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\documentclass{aa}
%\documentclass[referee]{aa}
\usepackage{graphicx}
\usepackage{subfig}
\usepackage{txfonts}
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\usepackage{longtable}
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\hypersetup{
 colorlinks   = true, %Colours links instead of ugly boxes
 urlcolor     = blue, %Colour for external hyperlinks
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 }

\begin{document}

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\newcommand{\phoebee}{{\tt PHOEBE}}
\newcommand{\fotel}{{\tt FOTEL} }
\newcommand{\fotele}{{\tt FOTEL}}
\newcommand{\korel}{{\tt KOREL} }
\newcommand{\korele}{{\tt KOREL}}
\newcommand{\binsyn}{{\tt BINSYN} }
\newcommand{\binsyne}{{\tt BINSYN}}
\newcommand{\pyt}{{\tt PYTERPOL} }
\newcommand{\pyte}{{\tt PYTERPOL}}

\newcommand{\tria}{\hbox{$\bigtriangleup$}}
\newcommand{\ubv}{\hbox{$U\!B{}V$}}
\newcommand{\ubvr}{\hbox{$U\!B{}V\!R$}}
\newcommand{\bv}{\hbox{$B\!-\!V$}}
\newcommand{\ub}{\hbox{$U\!-\!B$}}
\newcommand{\hp}{$H_{\rm p}$}

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\newcommand{\oc}{$O-C$}
\newcommand{\ha}{H$\alpha$ }
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\newcommand{\hae}{H$\alpha$}
\newcommand{\hbe}{H$\beta$}
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\newcommand{\hip}{$Hipparcos$}
\newcommand{\ond}{Ond\v{r}ejov}


\title{Improved reduction and standardization of half a century\\
of \ubv\ photometry at Hvar\\
I. Overview, emission-line stars and binaries
\thanks{Based on photometric observations from
the Hvar Observatory and ESA Hipparcos Satellite.
 } }
\author{
H.~Bo\v{z}i\'c\inst{1}\and
P. Harmanec\inst{2}\and
J.~Horn\thanks{Ji\v{r}\'\i\ Horn passed away on Dec. 13, 1994}\inst{3}\and
K.~Juza\thanks{Karel Juza passed away on March 13, 1994}\inst{3}\and
P.~Koubsk\'y\inst{3}\and
S.~K\v{r}\'\i\v{z}\thanks{Svatopluk K\v{r}\'\i\v{z} passed away on Feb. 23, 2018}\inst{3}\and
P.~Mayer\thanks{Pavel Mayer passed away on Nov. 7, 2018}\inst{2}\and
P.~Hadrava\inst{4}\and
D.~Ru\v{z}djak\inst{1}\and
D.~Sudar\inst{1}\and
S.~\v{S}tefl\thanks{Stanislav \v{S}tefl passed away on June 11, 2014}\inst{3}\and
M.~Wolf\inst{2}\and
P.~Zasche\inst{2}\and
M.~Bro\v{z}\inst{2}\and
J.~Havelka\thanks{Josef Havelka passed away on June 19, 2009}\inst{3}\and
J.~Honsa\inst{3}\and
V.~Kocourek\inst{3}\and
M.~Tlamicha\inst{3}\and
F.~\v{Z}\v{d}\'arsk\'y\inst{3}\and
A.~Harmanec\inst{5}\and
J.~Jon\'ak\inst{2}\and
A.~Opli\v{s}tilov\'a\inst{2}\and
I.~Piantschitsch\inst{6,7,8}\and
I.~Skoki\'c\inst{1}\and
J.~\v{S}vr\v{c}kov\'a\inst{2}\and
K.~Vitovsk\'y\inst{2}\and
D.~Vr\v{s}nak\inst{9}\and
M.~Zummer\inst{5}
}
\institute{
Hvar Observatory, Faculty of Geodesy, Zagreb University,
Ka\v ci\'ceva~26, HR-10000 Zagreb, Croatia
  \and
Astronomical Institute, Faculty of Mathematics and Physics,
Charles University, V~Hole\v{s}ovi\v{c}k\'ach~2,\\
CZ-180~00~Praha~8, Czech Republic
  \and
Astronomical Institute of the Czech Academy of Sciences, Fri\v{c}ova~298,
CZ-251~65~Ond\v{r}ejov, Czech Republic
  \and
Astronomical Institute of the Czech Academy of Sciences, Bo\v{c}n\'\i~II~1401/1,
CZ-141~00 Praha~4, Czech Republic
 \and
Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
 \and
Institute of Physics, University of Graz, Universit\"atsplatz 5, A-8010 Graz,
Austria
 \and
Departament de F\'\i sica, Universitat de les Illes Balears (UIB), E-07122, Spain
 \and
Institute of Applied Computing \& Community Code (IAC3), UIB, Spain
 \and
Faculty of Electrical Engineering and Computing, University of Zagreb,
 Unska~3, HR-10000 Zagreb, Croatia
}
\date{Received \today}

\abstract {We present a summary report on 52 years of systematic photoelectric
\ubv\ observations of early-type emission-line stars {\bf and binaries of all
luminosity classes} secured by a~number of mainly
Croatian and Czech observers at the Hvar Observatory.
All these observations were {\bf carefully re-reduced} to the standard \ubv\ system
defined by the Johnson standard stars through the nonlinear transformation formul\ae.
{\bf These observations represent a very unique set of homogeneous observations,
covering also the near ultraviolet parts of the electromagnetic spectrum, where
the hot stars emit the maximum of their flux. This is extremely important addition to
the modelling of emission-line envelopes since the existing models are usually only
based on $V$ magnitude observations and/or very broad-band space photometries.
Our observations indicate that all emission-line stars of all luminosity classes}
are light and colour variables, but there is great individuality in the behaviour
of each star and often different variability patterns are found in the individual
passbands. We tried to classify various types of variability only on the basis of Hvar
photometry, complemented by the Hipparcos \hp\ photometry transformed
to Johnson $V$ passband, since these observations conveniently fill
the gap in Hvar observations. {\bf We also provide simple statistics of the recognized
types of variations and a~list of known binaries and multiple systems.
Observations of various other types of variables, including accidental discoveries,
will be reported in a~follow-up paper II.}
}

\keywords{stars: early-type --
  stars: emission-line (Be) --
  binaries: eclipsing --
  binaries: ellipsoidal}

\maketitle

\section{Introduction}
The astronomical observatory at Hvar, Croatia was founded in 1972 as a joint
enterprise of several astronomical institutions from former Yugoslavia and
Czechoslovakia. {\bf The instrument used for stellar photometry is}
a 0.65~m Cassegrain reflector with a~single-channel photoelectric
photometer operating with the \ubv\ filters. The early history
was summarised by \citet{mayer2013} and \citet{hb2013}
and the instrumentation and the original reduction
techniques were described in \citet{mayer77} and \citet{hvar2}.
The first observations were secured on July 29, 1972 and continued more or less
systematically since then, with the only longer gap (caused by the war
in the disintegrating Yugoslavia) from February 1991 until September 1993.
In 2013, a Cousins $R$ filter was installed to the photometer and since
then we have been obtaining four-colour observations. For consistency, we report
here the results of \ubv\ observations only but the archives of four-colour observations
will also be made publicly available after the publication of this study -- see
Sect.~\ref{data}. {\bf Readers interested in more details on the stellar photometric
programs are referred to Appenxix~\ref{apa}.
\footnote{This, and all other appendices are only available on ZENODO -- see
\url{https:\\...}}
}

\section{Investigation of early-type emission-line objects}
{\bf When our observing program started, little was known about light
variability of early-type emission-line stars and the possible causes
of the Be phenomenon. We therefore decided to monitor many bright stars,
including already known binaries, which have exhibited Balmer emission lines
during their recorded history, not restricting our program to only those
objects, which are now by some investigators called ``classical Be stars",
i.e. stars of apparent luminosity classes III to V. We were, and still are
of the opinion that hot emission-line objects should be viewed in their
complexity. This is supported, for instance, by the recent finding by
\citet{alzbeta2025} that the B0Ia object $\varepsilon$~Ori is not probably
a genuine supergiant but a rapidly rotating and highly flattened object
with circumstellar matter.}
  Our main motivation at that time was an~attempt to test the
binary hypothesis of the origin of the Be phenomenon \citep{kh75,hk76}.
The idea was that if Be stars are indeed mass accreting components
of binary system in the stage of large-scale mass transfer, with Roche-lobe
filling secondaries, one should find a non-negligible number of
eclipsing and ellipsoidal binaries among them. Although we later indeed found
several such systems, for instance CX~Dra \citep{zarf10,cxdrahorn,cxdrahvar},
KX~And \citep{kxand01,zarf14}, V360~Lac \citep{zarf17,zarf24}, BR CMi \citep{zarf30},
or HD~81357 \citep{zarf31}, for the majority of the observed Be stars we discovered
long-term light and colour changes related to the changes in their circumstellar
envelopes (seen in parallel spectroscopy), on a time scale of years;
see, for instance, \citet{zarf6,zarf7a,zarf7b,zarf11} and the three summary reports
\citep{hvar4,hvar5,hvar5d}.

The first three selected Be stars, V744~Her = 88~Her, V439~Her = 4~Her, and
EW Lac = HD 217050 were observed already in 1972. Our discovery that essentially
all Be stars are light and colour variables was quite important.
At that time, Be stars were sometimes used as the comparison stars in various
observing programs of differential photometry. Perhaps the most interesting is
the case of V1294~Aql = HD 184279, which was recommended as the secondary
standard of the \ubv\ system -- see \citet{zarf11}.
That prompted us to prepare a list of all at that time known bright Be stars
{\bf of all luminosity classes having the Bright-Star catalog (HR) numbers and
select suitable comparison and check stars for them. We again refer
readers for more details to Appendix~\ref{apa}.

When it turned out that only a smaller part of hot emission-line objects are
in the stage of mass transfer, new suggestions appeared. They sought the agent
creating the envelopes in the equatorial outflow of matter, first advocated by
\citet{struve31} and argued that the outflow is facilitated by stellar
non-radial pulsations (NRP) \citep[e.g.][]{baade82,bolton82, percy83}.

\citet{pols91} argued that the majority of Be stars are products of
the previous mass transfer, during which
they gained their high rotation \citep[as suggested already by][]{kh75} but that
their current companions are compact hot stars and also advocated the idea that
the Be phenomenon is often related to outflow, not accretion.
The idea that the majority of Be stars are products of mass-exchange in binaries
has then been further developed by, e.g., \citet{boubert2018,naze2022,dufton2022}
or \citet{rubio2023}.

Interpretation of long-term $V/R$ changes of the Balmer emission lines
in terms of one-armed density waves was suggested by \cite{kato83} and
developed by \citet{okazaki91} and \citet{okazaki97}. Modelling of
emission-line profiles progressed with the model of viscous decretion disk
by \citet{carciofi2012} and the {\tt Bedisk} and {\tt Beray} models
by \citet{sigut2007,mcgill2011} and \citet{silaj2014}.

Later, the idea that a~constructive interference of several pulsational modes
can trigger a~temporal outflow of material into the disk has been developed
\citep[e.g.][]{rivi98,carciofi2011,baade2017} or \citet{bartz2025}.
See also the review by \citet{rivi2013} for one widely accepted
current interpretation of the Be phenomemon.

At first glance, it might appear that the ground-based \ubv\ photometry is no longer
interesting at the era of accurate space phometries from instruments like
MOST \citep{walker2003},
CoRoT \citep{borde2003},
Kepler \citep{jenkins2010},
BRITE Constellation \citep{weiss2014} or
TESS \citep{tess}.
However, the value of the data we are presenting
in this study lies in the fact that they represent probably the longest series
of homogeneous and well calibrated observations, and especially for the hot stars
they provide also the monitoring in the ultraviolet part of the stellar flux, where the
radiation of hot stars dominates. It can also be conveniently combined with the
spectroscopic monitoring of emission-line stars provided in the Be Star spectra
(BeSS) database \citep{neiner2011}.
}

\section{The observational strategy and the new reduction
of all observations since 1972}

\subsection{Principles of our observational strategy}
Since our motivation, especially for the dominant Be-star program, was
to ensure a stable and accurate transformation to the standard
Johnson system \citep{john53,john54}, we soon realised that a non-linear
transformation formul\ae\ are required for the conversion of
extinction-free instrumental magnitudes to the standard Johnson magnitudes.
It is also necessary to derive the coefficients
of these transformations from all observations of standard stars in each
observing season \citep{hhj94}. The strategy of Hvar observations, developed
first for the Be star program but later used for all observing programs,
was that we prepared a list of all known bright Be stars north of declination
of $-30^\circ$, which were listed in the Bright Star Catalogue
\citep{hoffleit82}, and a few fainter ones. For all of them, we selected
suitable comparison and check stars. If more Be stars were found close
to each other in the sky, we observed
them all together, using the same comparison and check stars.
Since most of our observations dealt with early-type blue
stars, we also selected the so-called red standards for each group, to
facilitate good seasonal transformation.

Whenever possible, we have chosen the {\bf comparison stars},
for which the \ubv\ photometry obtained by Johnson and
his collaborators was available. Our primary source was the summary
publication by \citet{john66}. It was, of course, a "must" for
the red standards. This allowed us to save observing time. Comparisons,
checks, and red standard stars with known \ubv\ magnitudes could be used
for both, the monitoring the extinction during observing nights and for seasonal
transformation to the standard \ubv\ system.
However, it turned out that the stars, which have only a few original
Johnson observations, suffered from rather large accidental errors.
Our task then was to improve the original Johnson values but to preserve
the original Johnson system over the whole range of the Hertzsprung -- Russell
(HR) diagram.

We used the program suite HEC22/SORTARCH/VYPAR for data reduction from the
whole observing seasons, sorting and creating data archives, and for data
extraction. \footnote{The program suite for data reduction,
sorting and archiving, several auxiliary programs, manual, test examples,
and data files can be downloaded at
\url{https://astro.troja.mff.cuni.cz/projects/hec22/}}
The reduction program HEC22 proceeds as follows.
For each star and the time of observation, the zenith distance $z$ is
calculated from its equatorial coordinates recalculated for the time of
observation and the program derives the accurate air mass after
\citet{bemporad}:

\begin{eqnarray}
 X = \sec z-0.0018167Q-0.02875Q^2-0.0008083Q^3,\label{airok}
\end{eqnarray}
\noindent where
\begin{eqnarray}
 Q \equiv \sec z-1.
\end{eqnarray}

Transformation coefficients $G_i$ (i = 1,28) between observed
instrumental magnitudes, denoted $v$, $b$, $u$, and $r$, and extinction-free
magnitudes $v_0, b_0, u_0$, and $r_0$, determined (or fixed) separately
for each night, include the first-order extinction coefficients and
a~possibility to model time variations of the linear extinction
coefficients during each night through polynomials up to the
5$^{\rm th}$ degree as a function of time $t$.
The corresponding equations read as follows:

\begin{eqnarray}
v&=&v_0+G_1\nonumber\\
 &+&(G_5+G_9\,t+G_{13}\,t^2+G_{17}\,t^3+G_{21}\,t^4+G_{25}\,t^5)\,X,\\
b&=&b_0+G_2\nonumber\\
 &+&(G_6+G_{10}\,t+G_{14}\,t^2+G_{18}\,t^3+G_{22}\,t^4+G_{26}\,t^5)\,X,\\
u&=&u_0+G_3\nonumber\\
 &+&(G_7+G_{11}\,t+G_{15}\,t^2+G_{19}\,t^3+G_{23}\,t^4+G_{27}\,t^5)\,X,\\
r&=&r_0+G_4\nonumber\\
 &+&(G_8+G_{12}\,t+G_{16}\,t^2+G_{20}\,t^3+G_{24}\,t^4+G_{28}\,t^5)X.
\end{eqnarray}

{\bf An example of how such fit can improve the model of all-sky magnitudes
during long nights is shown in Appendix~\ref{apb}.}

There is also a possibility to take into account a~linear or a~quadratic
drift of the zero point of the instrument. In that case, the drift is derived
via the yellow-magnitude observations and forced upon the data in
all other passbands. The corresponding equations then read as

\begin{eqnarray}
v &=& v_0+G_1+G_5\,X+G_{9}'\,t+G_{13}'\,t^2,\\
b &=& b_0+G_2+G_6\,X+G_{9}'\,t+G_{13}'\,t^2,\\
u &=& u_0+G_3+G_7\,X+G_{9}'\,t+G_{13}'\,t^2,\\
r &=& r_0+G_4+G_8\,X+G_{9}'\,t+G_{13}'\,t^2.
\end{eqnarray}

\noindent We applied this drift only in a few cases for the earlier analog
high-voltage amplifiers. Naturally, the coefficients $G_9'$ and $G_{13}'$
are not the same as the similarly denoted coefficients $G_9$ and $G_{13}$
in Eq.~(3). We never tried to combine the time change of the extinction
during the night with the zero-point drifts, since there would be a~strong
correlation between the two and the fit would be unstable.

   The colour transformation equations between the Johnson standard value
for each magnitude ($V,B,U,R$) and the extinction-free instrumental
magnitudes are linear in the $U-B$ index, but have the form of a third-degree
polynomial in $B-V$. This form is necessary to compensate for
the unavoidably non-linear effect of the Balmer jump on the magnitudes of
stars from mid-B to F spectral types \citep[see][]{cousins76}.
The colour extinction coefficients in the form recommended
by \citet{young91} are also included among the seasonal transformation
coefficients. It is our experience that this form of transformation
equations ensures the reproduction of the standard Johnson
system within 0\m01, even in~$U$, for any standard star.

The respective equations are as follows:

\begin{eqnarray}
v_0-V&=&H_1(B-V)+H_2(U-B)\nonumber\\
     &+&H_3(B-V)^2+H_4(B-V)^3\nonumber\\
     &+&H_5\,X\,B_4(B-V+0.5\,X\,B_4)+H_6,\\
b_0-B&=&H_7(B-V)+H_8(U-B)\nonumber\\
     &+&H_9(B-V)^2+H_{10}(B-V)^3\nonumber\\
     &+&H_{11}\,X\,B_4(B-V+0.5\,X\,B_4)+H_{12},\\
u_0-U&=&H_{13}(B-V)+H_{14}(U-B)\nonumber\\
     &+&H_{15}(B-V)^2+H_{16}(B-V)^3\nonumber\\
     &+&H_{17}\,X\,B_5(U-B+0.5\,X\,B_5)+H_{18},\\
r_0-R&=&H_{19}(B-V)+H_{20}(U-B)\nonumber\\
     &+&H_{21}(B-V)^2+H_{22}(B-V)^3\nonumber\\
     &+&H_{23}\,X\,B_5(U-B+0.5\,X\,B_5)+H_{24},
\end{eqnarray}

\noindent where $B_4 \equiv G_6-G_5$ and $B_5 \equiv G_7-G_6$ are
the linear extinction coefficients in the \bv\ and \ub\ colours.

We note that in our formalism, quantities with suffix 0 are not,
in fact, really extinction-free instrumental magnitudes, but
extinction-free magnitudes uncorrected for the colour
extinction, which is only taken into account in the seasonal transformation
equations, where they actually belong, since they depend on the colour
properties of the photometer, not on the properties of the Earth
atmosphere. {\bf The program derives the transformation coefficients iteratively,
using all nights of a given season denoted as suitable for that purpose
and starting either with the values derived during the previous seasons
or with an instrumental system, i.e. choosing all $H$ coefficients
equal to zero.}

We {\bf note} that it is necessary to obtain observations of a reasonably large
number of standard stars of different colours, luminosity classes, and
reddenings to derive reliable non-linear transformation coefficients $H_{i}$.
Since this is not always possible, e.g., due to bad weather, the latest
versions of the program HEC22 also allow the use of bilinear transformation
formulae, which contain no terms of the second and third power in $(B-V)$ and
converge to reasonable transformation coefficients in these bad-weather
conditions. This compromise is, however, at the expense of a~slightly worse
transformation into the standard system, yet still much better than what would result from the use
of the often applied linear transformation formul\ae.

The possibility to derive and use the linear transformation formul\ae\ is also
included (non-zero coefficients $H_1\&H_{6}$, $H_7\&H_{12}$,
$H_{13}\&H_{18}$, and $H_{19}\&H_{24}$). This can be justified in
situations when the observations only include objects with a limited range of
colours, or for passbands covering the flat parts of the stellar energy
distributions ($R$ or even $V$, for instance).

Since the non-linear transformations imply that all three passbands affect
the accuracy of the determination of the standard values for each
passband, we took care to use different integration times for each star in
each passband, usually longest for the $U$ passband, to obtain comparable
signal-to-noise ($S/N$) ratios in all of them (usual integration times being
between 10 and 25 seconds).

We always inspected individual nights of observations for a~given observing
season and assigned them one of three possible grades: excellent if the rms
of the fit of all-sky magnitudes for the standard stars observed was 0\m010
or lower, good for the rms between 0\m011 and 0\m015, and poor for the
rms exceeding 0\m015 in the \ubv\ passbands. Respective individual observations
were then treated with the weights 1.5, 1.0, and 0.5. Besides, we selected
nights with enough different standards observed and a large range of air masses,
and only for these nights, the all-sky data were archived in the all-sky
archive. The remaining nights were only used for the differential photometry
and are stored in the archive of differential observations, together with
information about the comparison star used. More details can be found
in the paper by \citet{hhj94}, {\bf where also all relevant references to
the development of methods of photoeletcric data reduction to a~standard
system are discussed}, and in the user manual to the program suite.


\subsection{Reasons for the complete revision of all observations secured
since 1972}
   Originally, our reduction program HEC22 used {\bf only linear extinction
coefficients, which were} assumed to remain constant
during each observing night. This is actually almost never so, even at
observing stations with good climate conditions such as La Silla or
Sutherland. For Hvar Observatory, located on an island at an altitude
of only 260~m above the sea level, the variations of linear extinction
during the night are usually quite large, especially during the summer seasons.
To cope with this problem, we had to split many observing nights into shorter
time segments and to derive the extinction for each segment separately.
This was not satisfactory because standard stars from many -- otherwise
good and long observing nights -- could not be used for seasonal
transformations. Only much later a version of the reduction program was
developed, which allows the monitoring of the variable extinction during
the observing night.
This was one of the reasons why we decided to undertake the tedious
task to re-reduce all observing seasons since 1972.

The other was the following: Although we took care during the first
revision of our system of standard Johnson \ubv\ values, as described
by \citet{hhj94}, we realised that we should base our standard system
on frequent observations of standard stars recommended by Johnson and
his collaborators.  Several years ago, we therefore derived robust mean
\ubvr\ values for all individual observations of the recommended Johnson
primary standards, for which extinction was measured, from \citet{john66}
study and used them in all consecutive observations at Hvar during good nights,
suitable for all-sky photometry.
Additionally, we did the same for several well-observed stars
from the list of 108 recommended Johnson secondary standards \citep{john54}.
{\bf For convenience of other observers, these robust \ubvr\ values for Johnson
standards are provided in Appendix~\ref{apc}: in Table~\ref{primstd} for
the primary standards, and in Table~\ref{secstd} for the selected
secondary standards.}

All selected stars were carefully checked for variability with the help
of individual Hipparcos satellite \hp\ photometry \citep{esa97} and
SIMBAD bibliography
\footnote{\url{http://simbad.u-strasbg.fr/simbad/sim-fid}}.

As shown already by \citet{hhj94}, the usual range of values of individual
observations for non-variable stars at Hvar is within 0\m02 to 0\m03.
This is comparable to the rms errors per one observation for the Johnson
standards used; see Tables~\ref{primstd} and \ref{secstd}. Accordingly,
the use of the selected Johnson standards, even those having possible
low-amplitude variations, has no systematic effect on the stability of
the Hvar standard photometric system.


\begin{figure*}[t]
\centering
\includegraphics[angle=0,scale=0.63]{ahv-v.pdf}
\includegraphics[angle=0,scale=0.63]{dhv-v.pdf}
\includegraphics[angle=0,scale=0.63]{ahv-b.pdf}
\includegraphics[angle=0,scale=0.63]{dhv-b.pdf}
\includegraphics[angle=0,scale=0.63]{ahv-u.pdf}
\includegraphics[angle=0,scale=0.63]{dhv-u.pdf}
\caption{A plot of rms errors of one observation of unit weight versus
magnitude for all three passbands. The left panels are for data from the all-sky
archive, the right ones for the data from the archive of differential
observations.}\label{rmsmin}
\end{figure*}

 The Johnson standards were then systematically observed
several times during each good observing night. Care was taken
to observe them in high and low air masses to "bracket" observations of
all other stars during each observing night.
We also carried out dedicated observations of all our comparison,
check, and red-standard stars, for which good Johnson values were missing.
This effort has continued till today and allowed us to get better standard
Johnson values for comparison, check, and red stars used in the early observing
seasons.

Subsequently, we repeated the reductions of all seasons since 1972. In the
vast majority of cases, this resulted in much better seasonal transformations
and a significant decrease in mean standard errors. However, to our
satisfaction, the final values of the standard all-sky \ubv\ magnitudes
do not differ too much from the values derived during
the first homogenisation \citep{hhj94}.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{51and-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{51and-b.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{51and-u.pdf}}
\caption{Individual differential observations \ubv\ observations of
the red standard 51~And, obtained relative to two different blue
comparison stars. Observations relative to 4~Per
($V=$5\m009, \bv$=-$0\m073, \ub$=-$0\m305) are shown by black circles and
those obtained relative to HR~189 ($V=$5\m674, \bv$=-$0\m125, \ub$=-$0\m571)
are shown by red circles. Observations from nights of poor quality are shown
by small symbols. Our standard all-sky values
for 51~And are $V=$3\m600(10), $B=$4\m881(10), and $U=$6\m312(11).}
\label{51and}
\end{figure}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{pher1d-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{pher1d-b.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{pher1d-u.pdf}}
\caption{The \ubv\ daily mean $V$, $B$, and $U$ differential observations
of the check star $\varphi$~Her = HD~145389 relative to $\upsilon$~Her
with their rms errors per one observation. Data from the night of dubious
quality are shown by smaller symbols.}
\label{phiher}
\end{figure}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{10lac-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{10lac-b.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{10lac-u.pdf}}
\caption{The \ubv\ seasonal mean $V$, $B$, and $U$ all-sky normal points with
their rms errors per one observation for the Johnson primary standard 10 Lac.}
\label{10lac}
\end{figure}

Our improved standard Johnson \ubv\ magnitudes for all the frequently
observed comparison, check, and red standard stars, which were later
used as our new standards, are in Table~\ref{tab01}. In Table~\ref{tab02}
we also provide our standard Johnson \ubv\ magnitudes for the less frequently
observed comparison, check, and red standard stars. We underline that these
stars were not used as our transformation standards, since their \ubv\ values
are naturally still less accurate.

\subsection{Notes on the accuracy of the observations and stability
tests of our standard system}
First, it is useful to explain what a~single observation means. In the early
years 1972 - 1978, strip-chart recorders were used. About 10 to 15~s long
integrations in the three filters were drawn on the paper, from time
to time followed by the sky readings in the same filters and gains of
the amplifier. These were graphically averaged and read out with a ruler.
It would not be straightforward to estimate their rms errors. The current
voltage-frequency converter used is controlled by the program
PEHVAR\footnote{Written by J. Horn and currently developed by P. Zasche}, which
records individual one-second integrations into a~separate file.
%Using it,
%it is sometimes possible to correct the mean value of the integration
%in situations such as when the star gets to the edge of the diaphragm
%near the end of measurement because of imperfect guiding.

 We provide several tests of the stability of our observations.

{\bf The general idea about the accuracy of Hvar photometry is well documented
by Figure~\ref{rmsmin}, where we show plots of the bottom envelope of diagrams
showing the dependence of the rms errors per one observation of unit weight
versus the magnitude of the object, both for the all-sky archive, and for
the archive of differential observations. This characterises the accuracy for
non-variable objects. It is encouraging to see that it is quite comparable
for all three passbands, thanks to somewhat longer integration times used
for the $U$ filter.
}

  The accuracy of Hvar observations of individual stars can also be estimated
with the help of the check stars used for each observed program star.
We underline that the check stars were always observed as frequently as
the corresponding program stars. The HD numbers of the check stars can be
found in Table~\ref{tab03} and their rms errors per one observation can be
found in Table~\ref{tab01}. For instance, the check star
HR~289 = HD~6114 has the rms errors 0\m009, 0\m009, and 0\m010 in $V$, $B$,
and $U$, respectively.

Already in some published studies, we have shown that our homogenised
magnitudes lead to very good reproduction of observed magnitudes
obtained at different observing sites, even from mountain observatories
like San Pedro M\'artir. This is well illustrated, for instance by
Table~2 of the paper by \citet{bozic2007}, where the differential
\ubv\ magnitudes of the check star $\varphi$~Her derived for
different seasons at the Hvar, San Pedro M\'artir, and Tubitak stations
are compared.  The mutual agreement of the values is excellent in all cases.


A very convincing test of the quality of our transformations into the
standard Johnson system is the case of the red standard 51~And. This star was
alternatively observed as the red standard in
two different groups, in both cases relative to blue and much fainter
comparisons, 4~Per and HR~189. As Fig.~\ref{51and} shows, the individual
values relative to both comparisons are stable in time
and close to our standard all-sky value for 51~And.

We also plot in Fig.~\ref{phiher} nightly mean values for
$\varphi$~Her = 11~Her = HD~145389. This star was used as the check star
in observations of the Be star V839~Her and was observed since 1972. Therefore,
it provides a good idea about the accuracy of Hvar observations over time.
It is now known to be a~565~d spectroscopic binary seen nearly pole-on,
a~rotating star with a 3\fd708 period and also a low-amplitude pulsating star
\citep[see][and references therein]{kochuk2021}. As Fig.~4 in their paper shows,
the light variability has a~full amplitude lower than 0\m01.

We also investigate the secular stability of the transformation to the standard system
on the example of the Johnson primary standard 10~Lac, which was regularly observed in Hvar
since 1974.  In Fig.~\ref{10lac} we show seasonal mean values with their rms errors.
Once again, the secular stability of the values is very satisfactory.
Thus, we believe that the standard Hvar \ubv\ values for all our standards can be trusted
and used in other observing programs elsewhere, {\bf including the CCD observations using
Johnson filters}.


%\clearpage
{\onecolumn
\begin{longtable}{rrrrrrcrrr}
\caption{\label{tab03} A complete list of 106 early-type emission-line stars observed at
Hvar Observatory, number of their observations, the comparison and check stars used, and
the orbital period and eccentricity if known, with references to sources of binary orbits.}\\
\hline\hline
Star   &HD/BD &    No. of     &Comp.&Check&Spectral&P&e&Ref.\\
name   &number&     obs.&      HD/BD&  HD&type & (days)&\\
\hline
\endfirsthead
\caption{continued}\\
\hline\hline
Star   &HD/BD &    No. of     &Comp.&Check&Spectral&P&e&Ref.\\
name   &number&      obs.     &HD/BD&   HD&type    & (days)&\\
\hline
\endhead
\hline
\endfoot
10 Cas         &   144&  18&  2626&  2011&B9IIIe&-&-&-\\
V742 Cas       &   698&   6&  2626&  2011&B5II-IIIe+BVI&55.9233&0.0&33\\
$\kappa$ Cas   &  2905&  17&  2626&  2011&B1Iae&-&-&-\\
$\omicron$ Cas &  4180& 895&  4142&  6114&B5III-IVe&1031.55&0.0&2\\
$\gamma$ Cas   &  5394& 137&  2626&  2011&B0.5IVe&203.52&-&3\\
V442 And       &  6226& 964&  4142&  6114&B3.5IIIe&-&-&-\\
$\varphi$ And  &  6811& 504&  4142&  6114&B7e&-&-&-\\
HD 9709        &  9709&   7&  4142&  6114&B8Ve&-&-&-\\
$\varphi$ Per  & 10516& 678& 12303& 11291&B0.5IVe+sdOB&126.6731&0.0&7\\
V777 Cas    & 11606&  11& 12303& 11291&B2Ve&-&-&-\\
V780 Cas    & 12302&   9& 12303& 11291&B1:V:pe+sdOB&-&-&5\\
HR 654      & 13854&  13& 12303& 11291&B1Iabe&-&-&-\\
V554 Per    & 14818& 146& 12303& 11291&B2Iae&-&-&-\\
HR 894      & 18552& 118& 18411& 19736&B7IVe&-&-&-\\
RX Cas      & +67 244& 361& 18962& 19556, 19193&B3e+K1III&32.3301&0.0&6\\
HR 1051     & 21551&  30& 21278& 24546&B8Ve&-&-&-\\
$\psi$ Per     & 22192&  29& 21278& 24546&B5Ve&126.6982&-&7\\
HR 1113     & 22780&  41& 21856& 23193&B7Ve&-&-&-\\
13 Tau      & 23016& 114& 23324& 23288&B7Ve&-&-&-\\
%$\omicron$ Per & 23180&  33& 21856& 23193&B0.5IIIe&4.4196&0.0&39\\
17 Tau      & 23302& 367& 23324& 23288&B6IIIe&-&-&-\\
V971 Tau    & 23480& 265& 23324& 23288&B6IVe&-&-&-\\
HR 1160     & 23551&  17& 21278& 24546&B8Ve&-&-&-\\
$\eta$ Tau     & 23630& 205& 23324& 23288&B7IIIe&-&-&-\\
BU Tau      & 23862& 469& 23324& 23288&B8Ve&218.34&0.0&8\\
MX Per      & 25940&  32& 21278& 24546&B3Ve&-&-&-\\
HR 1500     & 29866&  30& 33641& 29722&B8Ve&-&-&-\\
BV Cam      & 32343&   9& 39283& 34787&B3Ve&-&-&-\\
$\lambda$ Eri  & 33328&  24& 32249& 33224&B2IIIep&-&-&-\\
V960 Tau    & 36576& 392& 36589& 37711, 36819&B2IV-Ve&-&-&-\\
$\zeta$ Tau & 37202&1100& 36589& 37711, 36819&B2IVe&132.987&9\\
$\omega$ Ori& 37490&  90& 36591& 36351&B3Ve&-&-&-\\
V731 Tau    & 37967& 107& 36589& 37711&B4Ve&-&-&-\\
V696 Mon    & 41335& 318& 42690& 45546, 43023&B1Ve&80.913&0.0&10\\
HR 2231     & 43285&  36& 44783& 43526&B6Ve&-&-&-\\
AX Mon      & 45910&  40& 44783& 43526&B2e+K2II&232.499&0.0&6\\
HR 2370     & 45995&   7& 44783& 43526&B1.5Vne&103.1&0.0&11\\
HD 46150    & 46150&   3& 44783& 43526&O5V((f))z&-&-&-\\
HR 2418     & 47054&  63& 42690& 45546, 43023&B8IVe&-&-&-\\
$\psi^9$ Aur& 50658&  29& 49949& 52860, 50860&B8IIIe&-&-&-\\
AU Mon      & 50846&  15& 50109& 50169&B5V+F0&11.113&0.0&12\\
OT Gem      & 58050& 437& 58187& 59059&B2Ve&-&-&-\\
$\beta$ CMi & 58715& 168& 58187& 59059&B8Ve&-&-&-\\
BR CMi      & 61273& 103& 58187& 61341&B9.5e+G8III&12.919&0.0&13\\
UX Mon      & 65607& 152& 65199& 65005&A5IIIe+G2III&5.9044365&0.0&14\\
HR 3135     & 65875&  24& 63975& 71155&B2Ve&-&-&-\\
HD 81357    & 81357&  93& 82861& 77692, 81772&B8e&33.77458&0.0&15\\
$\kappa$ Dra&109387& 429&107193&115612, 104316&B6IIIe&61.5549&0.0&16\\
$\vartheta$ CrB   &138749& 158&138341&136849&B6Vnne&-&-&-\\
V839 Her    &142926& 685&142926&145389,141930&B7e&46.1921&0.0&17\\
$\delta$ Sco   &143275&  98&144470&142096&B0.3IVe&3950.8&0.938&18\\
$\chi$ Oph     &148184&  11&144470&142096&B1.5Ve&34.121&0.26&19\\
$\zeta$ Oph    &149757& 168&148367&147550&O9.2IVnne&-&-&-\\
V2315 Oph   &161261&   5&161677, 169420&----&kA0hB8Ve&-&-&-\\
V744 Her    &162732&1449&158414, 162132&162579&B6IIIe&86.7221&0.16&20\\
V2048 Oph   &164284& 164&164432&163641&B2Ve&-&-&-\\
V974 Her    &164447& 183&166182&166230&B8IVe&-&-&-\\
$\omicron$ Her &166014& 182&166182&166230&B9.5IIIe&-&-&-\\
NW Ser      &168797& 327&170200&169578&B2Vne&-&-&-\\
CX Dra      &174237&1167&173664&172883&B3e+F5III&6.696&0.0&21\\
$\beta$ Lyr    &174638& 544&176437&174602, 172044&B8II+B0e::&12.913779&0.0&22\\
V4024 Sgr   &178175&   1&177817&182678, 182645&B2Ve&-&-&-\\
$\upsilon$ Sgr &181616&  46&177817&182678, 182645&B2Vpe&137.9343&0.0&1\\
HD 183261   &183261&   1&184606&188260&B3IIe&-&-&-\\
7 Vul       &183537& 131&188260&184606&B4-5IVe&69.4212&0.113&23\\
V923 Aql    &183656&1620&183227&184663&B6e&214.716&0.0&24\\
$\beta$2 Cyg   &183914&  14&188260&184606&B8Ve&-&-&-\\
V1294 Aql   &184279&1709&183227&184663&B0.5IVe&192.91&0.0&25\\
HR 7482     &185859&  38&188260&184606&B3I&-&-&-\\
V1507 Cyg   &187399& 193&188170&186357&B8III+Be&27.9705&0.389&26\\
V395 Vul    &187811&  39&188260&184606&B2.5Ve&-&-&-\\
V1746 Cyg   &189687& 209&188892&193369&B3IVe&-&-&-\\
V1624 Cyg   &191610& 510&188892&193369&B2.5Ve+sdO&359.98&0.0&27\\
20 Vul      &192044& 130&190993&191747&B7Ve&-&-&-\\
QR Vul      &192685& 191&190993&191747&B3Ve&-&-&-\\
P Cyg       &193237& 122&188892&193369&B1-2Iae&-&-&-\\
25 Vul      &193911& 124&190993&191747&B6IVe&-&-&-\\
V2119 Cyg   &194335& 140&188892&193369&B2IIIe&63.146&0.0&28\\
V2120 Cyg   &194883&  74&194668&197618&B2Ve&-&-&-\\
HR 7843     &195554& 161&194668&197618&B8.5Ve&-&-&-\\
V1661 Cyg   &198478& 288&203245&199311&B2.5Iae&-&-&-\\
HR 7983     &198625&  78&203245&199311&B4Ve&-&-&-\\
V2140 Cyg   &199478&  90&203245&199311&B7Iae&-&-&-\\
V832 Cyg    &200120& 849&203245&199311&B1.5Ve+sdOB&28.1871&0.144&34\\
V1931 Cyg   &200310& 889&203245&199311&B1Ve&147.617&0.20&5\\
HR 8103     &201733&  71&203245&199311&B4IVe&-&-&-\\
$\upsilon$ Cyg &202904&   6&202349&204403&B2Ve&-&-&-\\
HR 8153     &203025&   8&208218&202214&B2IIIe&-&-&-\\
V382 Cep    &203467&  82&208218&202214&B3IVe&-&-&-\\
HR 8259     &205551&  21&207330&206259, 207793&B7IIIe&-&-&-\\
$\epsilon$ Cap &205637&   2&144206, 213420& --- &B3IIIe&128.3&0.0&29\\
HD 206773   &206673&  57&208218&202214&B0.5V:pe&-&-&-\\
EM Cep      &208392&  10&208218&202214&B1Vne&-&-&-\\
HR 8375     &208682&   8&208218&202214&B2Ve&-&-&-\\
8 Lac A     &214168& 151&217101&214680&B1Vne&-&-&-\\
HR 8682     &216057& 205&218470&219080, 212593&B7Ve&-&-&-\\
V360 Lac    &216200& 424&217101&214680&B3e+F9IV&10.0854&0.0&30\\
EW Lac      &217050&1281&218470&219080, 212593&B4IIIpe&-&-&-\\
V378 And    &217543& 267&217101&214680&B2.5Vne&-&-&-\\
$\omicron$ And &217675&1636&217101&214680&B6Ve&2525&0.24&35\\
KX And      &218393&1210&218470&219080, 212593&B0.5e+K1III&33.918&0.0&31\\
KY And      &218674& 970&218470&219080, 212593&B4Ve&-&-&-\\
LQ And      &224559& 590&223229&222439, 224342&B4Ve&7.41324&0.3&32\\
V639 Cas    &225094&  22&  2626&  2011&B2.9Iabe&-&-&-\\
MWC 327     &227611&   6&+35 3955&190919&B1:III/Ve&-&-&-\\
V1322 Cyg   &229221&   2&229234&229238&B0.2IIIe&-&-&-\\
\end{longtable}
\tablefoot{Column `References':
1...\citet{zarf25}; 2...\citet{zarf28}; 3...\citet{zarf29}; 4...\citet{bozic95}; 
5...\citet{klement2024}; 6...\citet{hec2001}; 7...\citet{mourard2015}; 8...\citet{zarf27}; 
9...\citet{zarf26}; 10...\citet{peters2016}; 11...\citet{naze2022}; 12...\citet{sahade82}; 
13...\citet{zarf30}; 14...\citet{sudar2011}; 
15...\citet{zarf31}; 16...\citet{zarf16}; 17...\citet{zarf18}; 18...\citet{tycner2011}; 
19...\citet{hec87c}; 20...\citet{zarf4}; 21...\citet{cxdrahorn}; 22...\citet{mourard2018}; 
23...\citet{hec2020}; 24...\citet{wolf2021}; 25...\citet{hec2022}; 26...\citet{hutchings73}; 
27...\citet{hec2025}; 28...\citet{klement2022a};  
29...\citet{rivi2006}; 30...\citet{zarf24}; 31...\citet{floquet89}; 32...\citet{jaymie91}; 
33...\citet{rivi2025}; 34...\citet{peters2013}; 35...\citet{grant88}
}

\begin{longtable}{rccccccc}
\caption{\label{tab04} Time intervals covered by Hvar observations of individual Be stars
and the total range of their recorded variability.}\\
\hline\hline
Star   &JD range&$V$ range&$B$ range &$U$ range &$B-V$ range&$U-B$ range\\
name   &-2400000&(mag.)&(mag.)&(mag.)&(mag.)&(mag.)\\
\hline
\endfirsthead
\caption{continued}\\
\hline\hline
Star   &JD range&$V$ range&$B$ range &$U$ range &$B-V$ range&$U-B$ range\\
name   &-2400000&(mag.)&(mag.)&(mag.)&(mag.)&(mag.)\\
\hline
\endhead
\hline
\endfoot
  10 Cas      &45307.3--56515.6& 5.558--5.614& 5.534--5.582& 5.332--5.385&-0.044 -- -0.005&-0.223 -- -0.196\\
  V742 Cas    &55791.5--55798.5& 7.078--7.089& 7.263--7.274& 6.854--6.870&+0.178 -- +0.187&-0.412 -- -0.397\\
 $\kappa$ Cas   &45307.3--56515.6& 4.115--4.211& 4.255--4.363& 3.486--3.595&+0.129 -- +0.163&-0.786 -- -0.756\\
  $\omicron$ Cas &45212.6--60583.5& 4.301--4.652& 4.291--4.685& 3.691--4.012&-0.073 -- +0.033&-0.673 -- -0.512\\
  $\gamma$ Cas   &45307.3--60362.3& 2.084--2.245& 1.954--2.153& 0.944--1.123&-0.141 -- +0.005&-1.078 -- -0.984\\
  V442 And    &45212.6--60583.5& 6.572--6.897& 6.592--6.867& 5.966--6.327&-0.064 -- +0.033&-0.646 -- -0.540\\
  $\varphi$ And     &45212.6--60583.5& 4.217--4.308& 4.163--4.271& 3.801--3.932&-0.085 -- -0.030&-0.403 -- -0.324\\
  HD 9709     &53026.3--54356.5& 7.085--7.179& 7.022--7.155& 6.586--6.740&-0.066 -- -0.007&-0.436 -- -0.414\\
  $\varphi$ Per     &44935.4--60583.5& 3.927--4.159& 3.795--4.049& 2.885--3.171&-0.188 -- -0.036&-0.952 -- -0.815\\
  V777 Cas    &53026.3--53388.3& 6.902--7.040& 6.976--7.096& 6.152--6.286&+0.044 -- +0.076&-0.837 -- -0.802\\
  V780 Cas    &53028.3--53388.3& 8.042--8.102& 8.322--8.374& 7.842--7.936&+0.268 -- +0.284&-0.482 -- -0.435\\
  HR 654      &44985.3--46696.6& 6.446--7.383& 6.734--7.621& 6.094--6.995&+0.234 -- +0.292&-0.644 -- -0.615\\
  V554 Per    &44935.4--50087.2& 6.187--6.318& 6.486--6.638& 5.878--6.054&+0.282 -- +0.327&-0.618 -- -0.545\\
  HR 894      &44860.6--54026.6& 6.105--6.181& 6.036--6.108& 5.642--5.710&-0.096 -- -0.024&-0.424 -- -0.372\\
  RX Cas      &42603.5--60330.3& 8.646--9.500& 9.777--11.037& 9.959--12.169&+0.919 -- +1.554&-0.114 -- +1.132\\
  HR 1051     &45307.4--46689.6& 5.828--5.871& 5.787--5.814& 5.469--5.495&-0.059 -- -0.027&-0.327 -- -0.302\\
  $\psi$ Per     &45307.4--46689.6& 4.194--4.247& 4.106--4.136& 3.508--3.547&-0.135 -- -0.073&-0.604 -- -0.573\\
  HR 1113     &44988.3--50087.5& 5.551--5.596& 5.491--5.524& 5.060--5.104&-0.088 -- -0.048&-0.440 -- -0.409\\
  13 Tau      &44863.6--54015.5& 5.668--5.710& 5.660--5.703& 5.371--5.452&-0.029 -- +0.009&-0.302 -- -0.220\\
  %$\omicron$ Per &44988.3--45359.3& 3.804--3.853& 3.853--3.910& 3.128--3.177&+0.024 -- +0.077&-0.748 -- -0.702\\
  17 Tau      &44863.6--60373.3& 3.638--3.764& 3.539--3.672& 3.149--3.298&-0.152 -- -0.073&-0.455 -- -0.345\\
  V971 Tau    &44863.6--60373.3& 4.170--4.235& 4.119--4.187& 3.679--3.816&-0.090 -- -0.027&-0.471 -- -0.344\\
  HR 1160     &45307.4--46689.6& 6.171--6.200& 6.236--6.257& 5.915--5.938&+0.043 -- +0.070&-0.327 -- -0.303\\
  $\eta$ Tau     &44863.6--60373.3& 2.875--2.962& 2.735--2.854& 2.385--2.505&-0.158 -- -0.062&-0.393 -- -0.303\\
  BU Tau      &43140.3--60583.5& 4.999--5.405& 4.919--5.377& 4.452--5.241&-0.113 -- -0.001&-0.476 -- +0.019\\
  MX Per      &43136.4--46689.6& 3.984--4.075& 3.965--4.046& 3.408--3.472&-0.106 -- +0.014&-0.574 -- -0.547\\
  HR 1500     &44921.5--52202.6& 6.058--6.096& 6.126--6.158& 5.813--5.871&+0.046 -- +0.086&-0.334 -- -0.275\\
  BV Cam      &45308.6--45697.4& 5.139--5.184& 5.077--5.099& 4.336--4.354&-0.089 -- -0.060&-0.748 -- -0.737\\
  $\lambda$ Eri  &51445.6--51520.5& 4.246--4.298& 4.060--4.117& 3.172--3.215&-0.217 -- -0.137&-0.925 -- -0.871\\
  V960 Tau    &44902.6--60583.6& 5.368--5.718& 5.447--5.737& 4.690--4.980&-0.016 -- +0.136&-0.832 -- -0.719\\
  $\zeta$ Tau    &43135.4--60583.6& 2.769--3.200& 2.570--2.993& 1.757--2.369&-0.278 -- -0.087&-0.866 -- -0.614\\
  $\omega$ Ori   &51512.5--59598.4& 4.441--4.597& 4.371--4.485& 3.601--3.726&-0.134 -- -0.070&-0.776 -- -0.732\\
  V731 Tau    &43136.4--46694.6& 6.197--6.270& 6.141--6.199& 5.489--5.583&-0.114 -- -0.034&-0.673 -- -0.603\\
  V696 Mon    &44902.6--59974.4& 5.179--5.302& 5.117--5.232& 4.280--4.396&-0.092 -- -0.015&-0.876 -- -0.780\\
  HR 2231     &44993.4--50865.3& 6.058--6.133& 5.943--6.037& 5.411--5.529&-0.140 -- -0.099&-0.532 -- -0.479\\
  AX Mon      &44993.4--53388.5& 6.684--6.810& 6.988--7.134& 6.344--6.771&+0.282 -- +0.380&-0.661 -- -0.351\\
  HR 2370     &49730.4--49751.4& 6.058--6.101& 6.000--6.031& 5.152--5.195&-0.078 -- -0.058&-0.848 -- -0.820\\
  HD 46150    &53388.5--53388.5& 6.716--6.728& 6.875--6.868& 6.048--6.051&+0.132 -- +0.145&-0.817 -- -0.807\\
  HR 2418     &44902.6--52561.6& 5.501--5.554& 5.411--5.466& 5.022--5.099&-0.107 -- -0.055&-0.411 -- -0.340\\
  $\psi^9$ Aur&45014.4--52940.5& 5.833--5.893& 5.769--5.828& 5.325--5.391&-0.096 -- -0.054&-0.454 -- -0.419\\
  AU Mon      &54862.4--55104.6& 8.221 -9.134& 8.275--9.323& 7.648--8.804&-0.003 -- +0.193&-0.637 -- -0.481\\
  OT Gem      &44977.4--58924.4& 6.061--6.509& 5.944--6.346& 5.097--5.541&-0.230 -- -0.071&-0.922 -- -0.760\\
  $\beta$ CMi &44977.4--58564.4& 2.862--2.917& 2.755--2.844& 2.473--2.593&-0.128 -- -0.062&-0.308 -- -0.242\\
  BR CMi      &55574.5--56015.3& 7.089--7.184& 7.355--7.433& 7.392--7.483&+0.233 -- +0.299&+0.005 -- +0.076\\
  UX Mon      &52655.4--55594.4& 8.230--9.343& 8.569--10.112& 8.341--10.789&+0.286 --+0.957&-0.233 -- -0.717\\
  HR 3135     &45056.3--53035.5& 6.444--6.505& 6.348--6.428& 5.602--5.653&-0.133 -- -0.052&-0.791 -- -0.721\\
  HD 81357    &55879.6--57116.4& 8.295--8.391& 8.459--8.553& 8.264--8.334&+0.118 -- +0.186&-0.251 -- -0.172\\
  $\kappa$ Dra   &42237.4--60454.4& 3.766--3.978& 3.624--3.882& 3.071--3.353&-0.218 -- +0.049&-0.637 -- -0.483\\
  $\vartheta$ CrB   &44801.4--58637.5& 4.128--4.230& 3.986--4.138& 3.443--3.628&-0.164 -- -0.073&-0.570 -- -0.449\\
  V839 Her    &41528.5--60520.4& 5.705--5.803& 5.572--5.710& 5.158--5.352&-0.162 -- -0.058&-0.447 -- -0.291\\
  $\delta$ Sco   &52068.4--60518.4& 1.579--2.231& 1.630--2.330& 0.705--1.208&-0.137 -- -0.147&-1.130 -- -0.861\\
  $\chi$ Oph     &54275.4--54290.4& 4.328--4.427& 4.637--4.737& 3.896--3.970&+0.290 -- +0.350&-0.781 -- -0.732\\
  $\zeta$ Oph    &52494.3--58682.4& 2.510--2.584& 2.522--2.615& 1.677--1.782&-0.027 -- +0.071&-0.886 -- -0.803\\
  V2315 Oph   &41896.4--42625.4& 8.240--8.461& 8.275--8.552& 8.106--8.398&+0.035 -- +0.100&-0.198 -- -0.105\\
  V744 Her    &41535.4--60580.3& 6.662--6.945& 6.504--6.858& 6.002--6.519&-0.191 -- -0.058&-0.557 -- -0.265\\
  V2048 Oph   &45105.5--60545.4& 4.636--4.898& 4.616--4.787& 3.737--4.056&-0.132 -- -0.001&-0.889 -- -0.703\\
  V974 Her    &45065.6--58395.3& 6.405--6.586& 6.339--6.508& 5.928--6.134&-0.101 -- -0.003&-0.419 -- -0.321\\
  $\omicron$ Her &45065.6--58395.3& 3.784--3.892& 3.720--3.921& 3.669--3.851&-0.123 -- +0.045&-0.142 -- +0.033\\
  NW Ser      &44433.4--48133.3& 6.019--6.191& 6.042--6.173& 5.381--5.595&-0.041 -- +0.035&-0.666 -- -0.578\\
  CX Dra      &42977.3--56094.4& 5.666--6.014& 5.658--5.959& 4.890--5.252&-0.143 -- +0.025&-0.818 -- -0.642\\
  $\beta$ Lyr    &49272.3--57949.5& 3.324--4.269& 3.303--4.323& 2.745--3.803&-0.052 -- -0.090&-0.628 -- -0.449\\
  V4024 Sgr   &53584.4--53584.4& 5.309--5.309& 5.308--5.308& 4.544--4.544&-0.001 -- -0.001&-0.764 -- -0.764\\
  $\upsilon$ Sgr &53570.4--54297.4& 4.510--4.620& 4.627--4.769& 4.055--4.190&+0.093 -- +0.149&-0.597 -- -0.555\\
  HD 183261   &54275.5--54275.5& 6.865--6.865& 6.854--6.854& 6.167--6.167&-0.011 -- -0.011&-0.687 -- -0.687\\
  7 Vul       &54273.4--59025.5& 6.317--6.388& 6.219--6.306& 5.677--5.771&-0.109 -- -0.073&-0.561 -- -0.503\\
  V923 Aql    &44073.4--60580.3& 5.983--6.166& 5.966--6.201& 5.618--6.018&-0.044 -- +0.095&-0.391 -- -0.102\\
  $\beta$2 Cyg   &46679.4--46695.4& 5.140--5.159& 5.051--5.069& 4.730--4.744&-0.098 -- -0.078&-0.327 -- -0.315\\
  V1294 Aql   &44073.4--60580.4& 6.788--7.565& 6.807--7.634& 5.997--7.587&-0.005 -- +0.173&-0.841 -- +0.002\\
  HR 7482     &46679.4--58682.5& 6.481--6.519& 6.859--6.913& 6.270--6.326&+0.376 -- +0.403&-0.613 -- -0.577\\
  V1507 Cyg   &43024.4--43760.4& 6.896--7.088& 7.082--7.260& 6.680--6.861&+0.103 -- +0.263&-0.463 -- -0.323\\
  V395 Vul    &46679.4--58682.5& 4.909--4.957& 4.726--4.792& 4.067--4.137&-0.183 -- -0.141&-0.700 -- -0.644\\
  V1746 Cyg   &46245.5--60583.3& 5.121--5.246& 4.990--5.084& 4.251--4.409&-0.168 -- -0.108&-0.747 -- -0.670\\
  V1624 Cyg   &42237.5--60583.3& 4.888--5.084& 4.721--4.943& 3.943--4.281&-0.216 -- -0.103&-0.850 -- -0.639\\
  20 Vul      &44432.5--60565.5& 5.867--5.945& 5.746--5.842& 5.285--5.405&-0.135 -- -0.089&-0.485 -- -0.428\\
  QR Vul      &44794.5--60583.3& 4.600--4.820& 4.453--4.644& 3.684--3.925&-0.227 -- -0.109&-0.799 -- -0.706\\
  P Cyg       &46287.4--55451.4& 4.715--4.877& 5.116--5.275& 4.559--4.718&-0.383 -- -0.450&-0.581 -- -0.513\\
  25 Vul      &44817.4--60565.5& 5.499--5.563& 5.395--5.487& 4.958--5.078&-0.120 -- -0.073&-0.460 -- -0.387\\
  V2119 Cyg   &46238.5--47022.4& 5.783--5.923& 5.616--5.758& 4.652--4.836&-0.190 -- -0.141&-0.981 -- -0.906\\
  V2120 Cyg   &45149.5--55068.4& 7.163--7.361& 7.221--7.345& 6.551--6.730&-0.019 -- +0.060&-0.672 -- -0.609\\
  HR 7843     &44431.5--55064.4& 5.863--5.942& 5.827--5.880& 5.574--5.675&-0.095 -- -0.009&-0.253 -- -0.166\\
  V1661 Cyg   &41528.4--53935.5& 4.740--4.896& 5.112--5.272& 4.651--4.835&+0.333 -- +0.424&-0.472 -- -0.404\\
  HR 7983     &46696.4--53592.5& 6.323--6.400& 6.264--6.342& 5.674--5.796&-0.074 -- -0.038&-6.616 -- -0.546\\
  V2140 Cyg   &43024.4--54662.5& 5.634--5.724& 6.097--6.192& 5.787--5.900&+0.424 -- +0.486&-0.334 -- -0.283\\
  V832 Cyg    &46258.6--60583.4& 4.451--4.837& 4.432--4.782& 3.489--3.887&-0.116 -- +0.013&-0.984 -- -0.860\\
  V1931 Cyg   &46281.5--60583.4& 5.289--5.503& 5.136--5.303& 4.152--4.405&-0.251 -- -0.122&-1.001 -- -0.890\\
  HR 8103     &46696.4--52100.5& 6.595--6.650& 6.454--6.514& 5.747--5.890&-0.164 -- -0.124&-0.707 -- -0.621\\
  $\upsilon$ Cyg &44817.4--44818.5& 4.342--4.371& 4.256--4.284& 3.433--3.460&-0.094 -- -0.081&-0.828 -- -0.815\\
  HR 8153     &48116.6--48123.6& 6.378--6.443& 6.585--6.666& 6.085--6.220&+0.191 -- +0.227&-0.507 -- -0.446\\
  V382 Cep    &45536.4--52282.2& 4.924--5.255& 4.942--5.222& 4.299--4.651&-0.128 -- +0.051&-0.694 -- -0.527\\
  HR 8259     &45155.5--59078.6& 6.153--6.202& 6.139--6.199& 5.875--5.947&-0.026 -- +0.001&-0.283 -- -0.238\\
  $\epsilon$ Cap &41929.5--41940.4& 4.582--4.613& 4.453--4.534& 3.811--3.880&-0.128 -- -0.079&-0.654 -- -0.642\\
  HD 206773   &52142.6--52282.2& 6.876--7.053& 6.980--7.183& 6.169--6.428&+0.087 -- +0.143&-0.830 -- -0.742\\
  EM Cep      &41954.5--54020.3& 6.975--7.115& 7.224--7.398& 6.665--6.851&+0.239 -- +0.296&-0.579 -- -0.540\\
  HR 8375     &48116.6--48123.6& 5.896--5.939& 5.807--7.873& 5.062--5.131&-0.102 -- -0.055&-0.747 -- -0.715\\
  8 Lac A     &43013.6--54026.5& 5.640--5.767& 5.483--5.662& 4.575--4.723&-0.191 -- -0.064&-0.950 -- -0.853\\
  HR 8682     &44432.6--51426.5& 6.117--6.199& 6.030--6.114& 5.528--5.674&-0.125 -- -0.043&-0.536 -- -0.440\\
  V360 Lac    &44473.5--53980.4& 5.862--5.994& 5.949--6.067& 5.442--5.579&+0.041 -- +0.112&-0.554 -- -0.469\\
  EW Lac      &41534.5--60199.5& 5.096--5.492& 4.958--5.361& 4.198--4.955&-0.165 -- -0.030&-0.778 -- -0.397\\
  V378 And    &42261.5--55460.4& 6.461--6.615& 6.317--6.530& 5.630--5.906&-0.180 -- -0.061&-0.743 -- -0.624\\
  $\omicron$ And &42614.6--60583.4& 3.498--3.784& 3.395--3.702& 2.861--3.256&-0.178 -- +0.000&-0.598 -- -0.427\\
  KX And      &42261.5--57621.5& 6.775--7.212& 7.092--7.596& 6.661--7.478&+0.251 -- +0.431&-0.551 -- -0.101\\
  KY And      &42614.5--57621.5& 6.686--6.894& 6.679--6.862& 6.075--6.317&-0.092 -- +0.059&-0.642 -- -0.513\\
  LQ And      &44433.5--60583.4& 6.498--6.598& 6.412--6.524& 5.793--5.920&-0.125 -- -0.035&-0.669 -- -0.554\\
  V639 Cas    &45307.3--55798.5& 6.201--6.273& 6.542--6.610& 6.011--6.099&+0.326 -- +0.347&-0.532 -- -0.506\\
  MWC 327     &44841.4--46689.4& 8.710--8.790& 9.074--9.148& 8.384--8.435&+0.335 -- +0.364&-0.721 -- -0.666\\
  V1322 Cyg   &44794.5--44843.3& 9.333--9.346& 10.190--10.223& 9.957--10.016&+0.844 -- +0.890&-0.233 -- -0.207\\
\end{longtable}
}

\twocolumn


\section{Long-term, phase-locked, and rapid light and colour changes
of Be stars observed at Hvar}
The list of all Be stars observed at Hvar, together with information
about the comparison and check stars used to their differential observations,
{\bf and MKK spectral types is in Table~\ref{tab03}. For known binaries,
also the orbital period, eccentricity and type of orbital light variability
is listed. In most cases, we give only one reference for the binary orbit, in which
previous studies are listed. Information} about the time interval covered
by their observations and the total range of variations recorded is
in Table~\ref{tab04}.

The following typical patterns of light and colour changes can be
distinguished:

 {\tt Long-term changes related to the strength and/or extent
of the Be envelope (LTEM).} These occur on a time scale of
years to decades and have two distinct alternatives, depending on the inclination
of the Be disk plane with respect to the observer: {\tt positive (LTEMp)},
when the brightenings are accompanied by the rise of the emission-line strength,
and {\tt inverse (LTEMi)}, when the light decreases are followed by
the emission-line rise \citep{hec83, hec94, hec2000, sigut2013}. We note
that in cases of intermediate inclination, a~given object can exhibit either
a~positive, or an inverse correlation in various epochs of observations, depending
on the extent of the Be envelope \citep[see, e.g.][]{hec2022}.

 {\tt Long-term cyclic changes {\bf (LTCV).}}
 {\bf They might be related to the long-term cyclic $V/R$
variations of the relative strength of the $V$ and $R$ peaks of the double
Balmer emission lines if the monitoring of corresponding spectral variations is available.
They} occur typically on a time
scale of several years and are related to non-axisymmetric geometrical
and/or dynamical changes of the structure of the Be disks. In the past,
they were interpreted as a gradual revolution of an elongated disk
\citep[see, e.g.][]{balle89}. {\bf Since the studies by \citet{okazaki91}
and \citet{okazaki97}}, they are usually understood as global
one-armed oscillations of the disks
and can also manifest themselves by the corresponding light changes
\citep[see the detailed discussion by][]{mennick97}. A recent example
of such changes was presented by \citet{wolf2021}. The problem is that
the LTVR sometimes occur simultaneously with the LTEM changes and it is
not easy to separate both effects
\citep[see, for instance][]{hec2022}.

 {\tt Light and colour variations related to the duplicity
of particular Be stars (MTBIN).} Such changes are periodic and
generally follow the orbital periods of the Be binaries
in question, but they are not easy to detect due
to the simultaneous presence of variations on other time scales.
In addition to clear cases of binary eclipses, they can also manifest themselves
as a combination of ellipticity and reflection, or occasional eclipses
of the outer parts of the disks. Numerous examples of such changes were
discussed, with corresponding references, by \citet{hhk2013}
and are documented by Hvar systematic photometry; see the
discussion of individual Be stars below.

 {\tt Rapid periodic or multiperiodic low amplitude changes (RAV).} These
brightness variations usually occur on timescales from about 0\fd1 to 2~d
and have been alternatively interpreted as pulsations or rotational modulation.
Since the typical observing strategy at Hvar was focused on monitoring
variations on longer time scales, Hvar observations are not very suitable
for analyses of such rapid changes, with the exception of several
dedicated observing campaigns on selected Be stars, for instance
$\zeta$ Tau \citep{bozic88}, $o$~And, KX~And, KY~And, LQ~And
and EW~Lac \citep{stagg88} or $\omega$~Ori \citep{balona2001}.

 {\tt Secular very long-term brightness decreases or increases
during the quiescest stages without strong LTEM changes {\bf (VLTV)}.} This
very long timescale of changes was probably first noted
for $\omega$~CMa by \citet{hec98} and empirically modeled in terms of
the viscous decretion disk model {\bf \citep{lee91,carciofi2009}}
by \citet{ghore2021, ghore2023}.
Several distinct examples of such behaviour were presented
by \citet{hec2022}. Understanding this type of
variability will require further observational and theoretical efforts.

   In the following, we discuss selected fifty two stars, which were observed more
systematically at Hvar. Because the observations at Hvar were interrupted
during 1990-1992, we complemented the Hvar $V$ series in the $V$ magnitude
time plots with the Hipparcos \hp\ photometry,
transformed to Johnson $V$ magnitude after \citet{hpbv}. These are shown
by red circles in all plots. The following notes on particular observed
Be stars are mostly related to LTEM, LTCV, VLTV, and/or MTBIN changes.
{\bf Here, we present examples of 19 interesting objects, showing different
characteristic variability patterns. Brief discussion of the remaining objects
can be found in Appendix~\ref{apd}.
}

\bigskip
 {\tt $o$ Cas = 22 Cas = HD 4180} This bright Be star is
the primary component A of a wide visual system AB WDS~J00447+4817.
\citet{zarf28} confirmed that it is also a spectroscopic binary with a~period
of 1031\fd6 and a rather large RV semi-amplitude of 22 \ks, which implies
a~large mass function. They also obtained a visual orbit with an~inclination
of 115$^\circ$ and since they did not detect any lines of the secondary,
they suggested that the secondary is actually a close pair of two A stars.
Such stars were indeed detected in the spectra studied by \citet{grund2007},
with a possible period close to 4 days \citep[see also][]{tou2013, hutter2021}.
Thus, it appears that the object is a hierarchical system Aa1, Aa2, and B.
\citet{zarf28} also found a period of 1\fd2578 in the residuals from
their RV orbit and showed large-amplitude cyclic light changes, based on
the Hvar photometry. Here, we present an extended series of Hvar observations in
Fig.~\ref{omicas}.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ocas-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ocas-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ocas-ub.pdf}}
\caption{The \ubv\ time variations of $o$~Cas. The red dots in this, and in all
following time plots for individual objects denote the Hipparcos \hp\ observations
transformed to Johnson $V$ magnitude after \citet{hpbv}.As mentioned in Sect.~2,
the accuracy of these observations can be judged from the rms errors per one
observation of the respective check star, which are provided in Table~\ref{tab01}.
For the check star HR~289 observed with $o$~Cas, they are 0\m009, 0\m009,
and 0\m010 for the $V$, $B$, and $U$ passbands, respectively.}
\label{omicas}
\end{figure}

\bigskip
{\tt V442 And = HD 6226}
This star was originally used as one of the check stars in our Be star observing program
and this led to the discovery of its light variability in the form of occasional brightenings,
accompanied by reddening in \bv\ and blueing in the \ub\ index. This finding was
published by \citet{hrvoje98}, who suggested that the object could be a Be star. This was
indeed confirmed by a detailed spectroscopic and photometric study by \citet{zarf22}, who
found that V442~And is a pole-on Be star with a positive correlation between brightness
and emission-line strength and pronounced line-profile variations, reminiscent of
an archetype Be star $\omega$~CMa, and varying with a regular 2\fd61507 period.
\citet{rich2021} published a very detailed study, based on numerous spectra and on
the KELT and TESS photometries. They estimated the spectral type as B2.5IIIe and confirmed
the period of line-profile changes. Analysing the \ha and \hb equivalent widths, they
found regular changes with two periods, 211\fd9, and 87\fd0. They also argued that the
emission-line episodes could be related to the interference of pulsational modes, resulting
in formations of transient circumstellar disks. Other published studies
are also summarised in their paper.
  The complete light curve of V442~And secured at Hvar is in Fig.~\ref{v442and}.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v442-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v442-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v442-ub.pdf}}
\caption{The \ubv\ time variations of V442~And.}
\label{v442and}
\end{figure}

\bigskip
{\tt $\varphi$~And = 42 And = HD 6811} This Be star is obviously observed
pole-on, shows a~single-peaked \ha emission profile and little light variability, and
was alternatively classified as B7Ve and B5IIIe \citep{jones2011, barnsley2013}.
It is also a member of a multiple visual system WDS~J01095+4715 and \citet{muter2010}
published a visual orbit with a period of about 202500~d.
Its mild light and colour variability {\bf would probably go unnoticed without} very systematic
monitoring and careful reduction; see Fig.~\ref{phiand}. It is characterised
by a {\bf steady slow light decrease on a very long (LTCV)} time scale, with no known episodes of more
rapid brightening or fading.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{phand-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{phand-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{phand-ub.pdf}}
\caption{The \ubv\ time variations of $\varphi$~And.}
\label{phiand}
\end{figure}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{phper-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{phper-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{phper-ub.pdf}}
\caption{The \ubv\ time variations of $\varphi$~Per.}
\label{phiper}
\end{figure}

\bigskip
{\tt $\varphi$~Per = 54 And = HD 10516} This object is a well-known
B0.5e+O6\,VI binary with a 126\fd7 period \citep[see][and references therein]
{poeckert81a,poeckert81b,gies93,thaller95,bozic95,gies98}.  \citet{bozic95}
compiled all the photometric and RV observations and summarised the early history of the system. They also derived an improved
orbital period of the system. Photometry, including the first part of
Hvar observations, shows only mild secular changes. They interpreted
the emission seen in \ion{He}{i}~6678~\AA\ as a double emission moving
with the secondary. However, \citet{stefl2000} and \citet{hummel2001}
argued that this emission actually originates in the part of the disk
of the primary, facing the hotter secondary and being illuminated by
it. \citet{mourard2015} resolved the secondary in their optical
interferometry and published the most detailed model of the
system to date, deriving the component masses of 9.6 and 1.2~\ms.
\citet{bozic2013} reported small sinusoidal $B$ magnitude light variation
with the orbital period.
The complete Hvar photometry is shown in Fig.~\ref{phiper}. It is seen
that the light variations are dominated by slow changes on the {\bf LTCV} time scale.
The $V$ magnitude varies in a cycle of more than 5000~d, while the \bv\ index
was gradually brightening over many years but started to get redder recently.

\bigskip
{\tt 17 Tau = HD 23302} This bright member of the Pleiades cluster,
also known as Electra, was reported to be a~single-line spectroscopic binary
with an orbital period of 100\fd46 by \citet{abt65}. They claimed
that the orbit, based on a limited set of RV measurements, is
not well determined. \citet{pearce&hill71} were not able to definitely
provide proof that the star was a~spectroscopic binary but left the
possibility open. \citet{torres2020} derived accurate RVs over
an interval of about 800 days and concluded that there is no evidence
of RV changes.
\citet{breger72} showed that 17~Tau is constant down to 0\m002-0\m003.
In his search for Maia variables \citet{mcnamara85} used 17~Tau as
a comparison star in the photometric search for the Maia candidates, finding
is to be constant, and its photometric constancy was also confirmed by
\citet{mcnamara87}. Also the Hipparcos \hp\ photometry does not show any
significant brightness changes. {\bf We note, however, that the star was
repeatably observed with TESS and these observations indicate cyclic
variations on a~time scale of about 1\fd1 with a full amplitude of
0\m0006 to 0\m0008.}
The Hvar photometry presented in Fig.~\ref{17tau} shows the presence of mild
long-term variations in brightness and colours on the level of several hundredths
of a~magnitude.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{17tau-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{17tau-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{17tau-ub.pdf}}
\caption{The \ubv\ time variations of 17~Tau.}
\label{17tau}
\end{figure}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{butau-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{butau-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{butau-ub.pdf}}
\caption{The \ubv\ time variations of BU~Tau.}
\label{butau}
\end{figure}

\bigskip
{\tt BU Tau = 28 Tau = HD 23862}  This well-known Be star is one of few
for which brightness and colour variations have been recorded systematically
for a long time, mainly due to the effort of Sharov and Lyutyj
\citep[see][and references therein]{sharov72,sharov97}. It is the primary
component of a binary with a highly eccentric orbit and an orbital period
of 218\fd03 \citep{zarf27, katahira96}. The orbit was not resolved
interferometrically by \citet{klement2024}.
The spectroscopic behaviour of this star is characterised by
remarkable changes between the normal Be state to Be-shell and Be
phase \citep{hirkog76, hirata95}. After a long
B phase that lasted until 1937, the star passed through 3
cycles of photometric and spectral variation.
The photometric variations show long-term cyclic changes
that started with a light decrease that lasted for some two
years. After reaching the light minimum, a gradual increase in
brightness to the initial level was temporarily replaced by another
mild light decrease, related to the development of a~metallic shell.
The period of the complete cycle lasts 34-36 years \citep{hirkog76, hec82}.
Using speckle interferometry \citet{mcalis89} found a third companion at
a separation of 0.22 sec. \citet{hec82} and \citet{Gies1990} (and some
others) considered a causal connection between the motion of that distant
companion and the occurrence of the shell phases. \citet{robert07}
recorded also the fourth companion of BU Tau at a distance of
4.66 sec. Besides a~few observations from the season 1976/77, Hvar
data cover almost the entire last cycle of photometric
changes. A secondary minimum is visible on the ascending part of
the curve, the depth of which is the most prominent at shorter
wavelengths; see Fig.~\ref{butau}. {\bf \citet{iliev2025} clearly
demonstrated that large changes in the strength of the \ha profile
occur shortly after each periastron passage in the 218\fd03 orbit.}
BU Tau shows the inverse correlation between the brightness and
emission-line strength. The behaviour in $U$-$B$/$B$-$V$ is shown
in Fig.~\ref{ubbvinv}. {\bf A~new detailed study of this object is
under preparation.}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ztau-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ztau-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ztau-ub.pdf}}
\caption{The \ubv\ time variations of $\zeta$~Tau.}
\label{zettau}
\end{figure}

\bigskip
{\tt $\zeta$~Tau = 123 Tau = HD 37302} This well-known and for a long time
studied Be star is a single-line spectroscopic binary with a 132\fd99 orbital
period, exhibiting also long-term cyclic RV and $V/R$ changes at certain time
intervals \citep[see the detailed studies by][where also references to original
papers can be found]{delplace70, hec84,zarf26,stefl2009,carciofi2009}.
There is a~clear correlation between the long-term RV and $V/R$ changes.
However, \citet{zarf26} have demonstrated that the light and colour behaviour
was different in each long cycle, alternating between positive and inverse
correlation. The first part of Hvar photometry has also been discussed in
\citet{bozic88}. In addition to long-term changes, these authors found
rapid variations with a 0\fd8 period (or a 1\fd6 period with a double-wave
phase curve). They also detected light decreases reminiscent of atmospheric
eclipses in some orbital cycles, which were missing in the others
\citep[see also Fig.~1 in][]{bozic2013}.
A complete set of Hvar observations is shown in Fig.~\ref{zettau}. The apparent
scatter of the data is mainly due to rapid large-amplitude changes.


\bigskip
{\tt V696 Mon = HR 2142 = HD 41335} This Be star was found to exhibit
two consecutive short-lived shell phases periodically every 80\fd85 days
\citep{peters71, peters72}.
Later, \citet{peters83} found that the object is a single-line spectroscopic binary
with an orbital period of 80\fd860, derived its radial-velocity curve and argued
that the observed shell phases are consequences of mass transfer in a binary system.
Peters originally argued that the secondary is a late-type Roche-lobe filling object
but no such object has ever been detected and \citet{waters91} proposed an~alternative
model, assuming that the secondary is a~small helium star and that the disk around
the primary is not an~accretion, but an~outflowing disk. \citet{peters2016}
indeed detected a weak signal in the IUE spectra corresponding to a hot subdwarf
companion, with a mass ratio of 0.07 and \tef around 43000~K. Using numerous optical
and IUE spectra, they also revised the orbital period to 80\fd913. \citet{sterken83} reported
a~0\m13 light decrease in the Str\"omgren $b$ magnitude. Hvar photometry of the
object has been secured rather systematically since the end of 1981 and was first
used, together with the Kitt Peak and Skalnat\'e Pleso photometry, to demonstrate that
no such light decrease occurred and that also the recurrent shell phases are not
accompanied by any light changes \citep{hecetal83}. The absence of light changes during
a~primary shell phase was also reported by \citet{dorren84}.
The time plot of the Hvar photometry, shown in Fig.~\ref{v696mon} shows only
a~very mild secular light decrease on the {\bf LTCV} time scale and little or no changes in
both colour indices. One could suspect some small rapid changes to be present, but we note
that the star is always observed at air masses larger than 1.55 at Hvar, which implies somewhat
higher scatter of individual observations.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v696-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v696-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v696-ub.pdf}}
\caption{The \ubv\ time variations of V696 Mon.}
\label{v696mon}
\end{figure}


\bigskip
{\tt $\varkappa$ Dra = 5 Dra = HD 109387} This bright Be star
observed in an~unusually high northern declination, was found to be
a~single-line spectroscopic binary with a 61\fd55 orbital period and a~small
RV amplitude by \citet{zarf16}. This was confirmed by subsequent orbital
solutions by \citet{saad2005} and \citet{saad2021}. However, all attempts
to detect the spectrum of the secondary failed. The secondary was finally
detected from near-IR interferometry by \citet{klement2022b}. They found
a~mass ratio of $0.117\pm0.009$, in agreement with the range estimated by
\citet{zarf16}. \citet{juza94} investigated spectral, polarimetric and
photometric observations from the past 100 years, including their own,
and argued that all observables varied with a period of 8406 days.
\citet{zarf23} concluded that this variability (which they estimated
to $8044\pm167$~days) is probably cyclic, not strictly periodic.
This is definitively confirmed by the extended series of Hvar
photometry, shown in Fig.~\ref{kapdra}, which shows a long systematic
brightness decrease since about JD~2451000 up to the present time.
This nicely correlates with the disappearance of the Balmer emission
documented over a similar time interval by \citet{klement2022b}.
{\bf A slow secular decrease on the VLTV scale seems to be present.}
\citet{balona2021} reported rotational modulation with a period of 1\fd134
from their analysis of TESS photometry.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kdra-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kdra-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kdra-ub.pdf}}
\caption{The \ubv\ time variations of $\kappa$~Dra.}
\label{kapdra}
\end{figure}

\bigskip
{\tt V839 Her = 4 Her = HD 142926} \ \ This Be star belongs to a few
Be stars systematically monitored at Hvar since 1972. It was identified as
a~single-line spectroscopic binary with a 46\fd2 period
\citep{zarf3, zarf5, zarf6}.
\citet{hhk2013} reported very mild light variations with the orbital period.
The time plot of all Hvar and transformed \hp\ photometric observations is shown
in Fig.~\ref{v839her}. So far, the only large light decrease, associated with
the formation of a new shell phase, was discovered by \citet{percy97} and is
also recorded in the \hp\ photometry. Since this is a very interesting case,
we made an exception and also included the observations by \citet{percy97}
in our time plot (shown by blue circles). This identifies V839~Her as
an~object with the inverse correlation between the light and the emission-line
strength \citep{zarf18}. This is corroborated by the study of \citet{sigut2023}.
These authors compared the inclination angles of a number of Be stars based
alternatively on the effects of gravitational darkening and on the \ha
emission line profile modelling. They found that V839~Her is seen almost
equator-on. In photometry, no secular variations outside the shell phase
have been detected in either the $V$ magnitude or \bv\ index, but are obvious
in the \ub\ index.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v839p-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v839-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v839-ub.pdf}}
\caption{The \ubv\ time variations of V839~Her. The blue dots denote observations
published by \citet{percy97}.}
\label{v839her}
\end{figure}


\bigskip
{\tt V744 Her = 88 Her = HD 162732} This Be star has also been
systematically monitored at Hvar since 1972. It was found to be a single-line
spectroscopic binary with an 86\fd7 period
\citep{zarf1, zarf2, zarf4, zarf7a, zarf7b}. Figure~\ref{v744her} shows
the light and colour changes of the object over 52~years of Hvar observations.
It is seen that the star underwent three episodes of secular light decreases,
accompanied by the emission and metallic shell episodes, the first one
being discussed in detail by \citet{zarf8}. It is a very good example of
an inverse correlation between the brightness and emission-line strength
(see Fig.~\ref{ubbvinv}). It is also seen that there is a slight secular brightness
decrease at the light maxima over the whole interval of Hvar observations
on the {\bf LTCV} time scale. There are almost no secular colour changes
in \bv\ but very pronounced ones in \ub. The secondary star is probably a~hot
and small object but it has never been directly observed
\citep[see, e.g.][]{wang2018}.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v744-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v744-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v744-ub.pdf}}
\caption{The \ubv\ time variations of V744~Her.}
\label{v744her}
\end{figure}

\bigskip
{\tt CX Dra = HD 174237}  This object is now known as a B2e+F5III
semi-detached binary with a 6\fd696 period seen under an intermediate
inclination of the orbit -- see the RV studies by
\citet{cxdrakou,zarf9,cxdrahorn,cxdramr}, and references therein.
The light and colour variations show cyclic changes correlated with
the variations of the strength of the \ha emission on a time scale
of several hundred days, showing a positive correlation
\citep{zarf10,cxdrahvar}. In addition to that, there are low-amplitude
phase-locked light changes with rather unusual properties -- see
Fig.~3 in \citet{cxdrahvar}. The lower envelope of these changes
is reminiscent of ellipticity and reflection in the undisturbed
state, but frequent brightenings are seen. We show the complete
light and colour changes recorded at Hvar in Fig.~\ref{cxdra}.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{cxdra-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{cxdra-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{cxdra-ub.pdf}}
\caption{The \ubv\ time variations of CX~Dra.}
\label{cxdra}
\end{figure}

\bigskip
{\tt V923 Aql = HD 183656}  This Be star was found
to be the primary component of a 214\fd7 binary by
\citet{zarf13}. Its very detailed study, based on all available
spectral and photometric observations over many decades was
published by \citet{wolf2021}. They documented its long-term,
orbital, and rapid variations. The object is a typical example of the
inverse correlation between the brightness and emission-line strength.
Although it exhibits large-amplitude cyclic RV and $V/R$ variations
with cycle lengths between about 1800, and 3000 days in RV, $V/R$,
$V$ magnitude, and \ub\ index, its \bv\ index remains secularly
stable and close to zero. Rapid changes, if periodic, may follow
a 0\fd8442 period. In Fig.~\ref{v923aql} we show the time plot
of Hvar photometry, extended a bit for more recent observations.
No evidence of changes on the longest {\bf LTCV} time scale is seen.


\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v923-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v923-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v923-ub.pdf}}
\caption{The \ubv\ time variations of V923~Aql.}
\label{v923aql}
\end{figure}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1294-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1294-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1294-ub.pdf}}
\caption{The \ubv\ time variations of V1294~Aql.}
\label{v1294aql}
\end{figure}

\bigskip
{\tt V1294 Aql = HD 184279} This is one of the Be stars with the
largest recorded range of light variations. Its amazing and complicated
spectral, light and colour variations were recently described in detail
in the study by \citet{hec2022}, who discovered that the object is also
a spectroscopic binary with a 192\fd9 period. The readers are referred to this
study. Here we only show the extended series of photometric observations
from Hvar in Fig.~\ref{v1294aql}. It is seen that
the brightness of the object is still rising and is maximal throughout the
recorded history.

\bigskip
{\tt V1624 Cyg = 28 Cyg = HD 191610} \ \  This Be star is well known for its
pronounced rapid photometric variations
\citep[for instance]{percy77,mills79,kreso90,hvar5}. \citet{baade2018} analyzed long
strings of photometry from the BRITE and SMEI satellites in relation
to the long-term variations of the strength of the \ha emission. They identified
a number of rapid periods ranging from 0\fd318 to 0\fd759, some of them being
combinations of others, and also a period of 19\fd634 with the largest amplitude,
seen in both, SMEI and BRITE data. They advocated the hypothesis that
the coupled non-radial pulsations are connected to mass transfer from
the stellar photosphere to the Be star disk. \citet{wang2018} tried to detect new
hot subdwarf companions to Be stars in the IUE spectra. For V1624~Cyg they
tabulated RVs for 25 spectra. \citet{wang2021} investigated far-UV spectra from
the Imaging Spectrograph of the Hubble Space Telescope (HST/STIS) and were
unable to find any lines of the secondary.
\citet{klement2022a} observed the object interferometrically with the CHARA array
and tentatively suggested an~orbit with a~246 d period. Later, \citet{klement2024}
concluded from extended interferometry covering about half of the orbital period
that the binary has a circular orbit with a 359\fd260 period and orbital
inclination of 119$^\circ$ (i.e. 61$^\circ$). Using RVs
from \citet{wang2018} and \citet{wang2021} papers and the probable distance
to the system, they estimated the masses of both stars. \citet{sigut2023} obtained
the inclination of the Be disk from \ha emission profile fitting as $40^\circ\pm5^\circ$,
and $69^\circ\pm17^\circ$ from the gravity darkening. It is therefore possible that the disk
lies in the orbital plane of the binary. \citet{hec2025} confirmed the orbital period
of 359\fd26 from the analysis of RVs derived from historical and new electronic spectra
and documented the long-term changes, showing that the object never lost the Balmer
emission during its recorded history. Hvar photometry is shown in Fig.~\ref{v1624cyg}.
The variations are dominated by rapid changes. There are obviously also changes on
longer time scales, but our limited set of observations
does not allow us to draw any firm conclusions about their character.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1624-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1624-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1624-ub.pdf}}
\caption{The \ubv\ time variations of V1624~Cyg.}
\label{v1624cyg}
\end{figure}

\bigskip
{\tt V832~Cyg = 59 Cyg = HD 200120} This object is the brightest
component A of the multiple visual system ADS~14526, with rather distant
fainter components B, C, D, and E.
Already \citet{hec82} speculated that -- at that time already known --
spectral variations and appearance of shell phases of V832~Cyg could be
related to the presence of as yet unknown close visual companion.
\citet{mcalister84} indeed discovered such a companion Ab and its orbital
variations have been monitored since then. Mason published a preliminary
orbit of the Aa-Ab pair with an orbital period of 161.5~yr and eccentricity
of 0.261 in Information Circular 175 of the IAU Comm. 26, but no details
were given. \citet{tolja87} discovered
radial-velocity (RV) and $V/R$ variations of the \ha emission with
a 29\fd14 period, which they interpreted as evidence that the object
is a spectroscopic binary. \citet{zarf21} carried out a detailed study
of this Be star, based on spectral and photometric observations from
several observatories. They indeed confirmed that V832~Cyg is a spectroscopic
binary with a 28\fd1971 period and argued that the true orbital RV amplitude
is best defined by the RVs measured on the steep emission wings of the
\ha line profile. This was nicely confirmed by the study of
\citet{peters2013}, who derived the RV curves of both binary components
from the far-UV spectra and proved that the secondary is a hot O type
subdwarf. \citet{zarf21} also documented
long-term light and colour changes with a positive correlation between
the light and emission-line strength combined with changes probably
attributable to one-arm disk oscillation. Prewhitening photometry
for these long-term changes, they found mild, but well-defined sinusoidal
light changes phase-locked with the orbital period.
The long-term brightness and colour variations of V832~Cyg extended to the
present time are shown in Fig.~\ref{v832cyg}.
One can see a steady increase in brightness throughout the time interval
covered by the \ubv\ observations, attributable to the variability
on the {\bf LTCV} time scale.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{59cyg-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{59cyg-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{59cyg-ub.pdf}}
\caption{The \ubv\ time variations of V832~Cyg.}
\label{v832cyg}
\end{figure}

\bigskip
{\tt EW Lac = HD 217050} \ \  This is a very active Be star, worth of a detailed
and complex study. It has been studied for about 100 years. Its Balmer emission
was variable until 1926. Then a~strong emission with sharp shell lines
visible over the whole Balmer series has developed and remained stable
until 1977, when the star became active again \citep[see, e.g.][]{hec79}.
These authors also showed that the star is a classical example of the positive
correlation between the brightness and emission-line strength.
\citet{stagg88} summarised the history of its photometric studies and suggested
a period of 0\fd72, close to timescales detected in previous studies, but
with a light curve variable with time. The spectra from the BeSS database
\citep{neiner2011} show that the emission gradually weakened and is virtually missing
since 2022.
Complete Hvar photometry shown in Fig.~\ref{ewlac} indicates that the star is
an example of variability on the {\bf LTCV} time scale, with secular brightness increase.
This is even better documented in Fig.~13 of \citet{hec2022}, where also earlier
photometry prior to start of Hvar observations is included. It is also seen that
the amplitude of rapid variations has decreased as the star was gradually losing
the Balmer emission.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ewlac-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ewlac-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ewlac-ub.pdf}}
\caption{The \ubv\ time variations of EW~Lac.}
\label{ewlac}
\end{figure}

\bigskip
{\tt $o$~And = HD 217675 = HR~8762}   This is a remarkable
Be star, for which rapid photometric variability was discovered
already during World War I, based on photoelectric observations
published by \citet{gutpra18}. Later, \citet{guth41} reported
a 1\fd5765 period of light variations and the star was long
considered to be a close contact binary
\citep[see][for the whole early history of the search for
the true period of its changes]{hec83}. Later, it was found
that $o$~And is a multiple system, containing a double-lined
spectroscopic binary with a 33\fd085 period, moving in a wide
orbit with the Be star, which dominates the optical spectrum
\citep{grant88, hec87}. {\bf In addition to, the object has two
speckle-interferometric companions. So far very uncertain closer
orbit has a possible period of 5.6~yr, defined by only five observations,
and the outer AB orbit has a period of 118.0~yr
\citep{zhuchkov2010,mitro2021}.}
The object exhibits rapid light variations
with a period of 1\fd571272 and a variable shape of the light curve
\citep{hec84b, hec87b, stagg88} and superimposed cyclic variation
with a regular cycle length over 2500 d (8.5 yr). \citet{hec84b}
suggested it could be related to a visual binary discovered by
\citet{wilson50} and causing recurrent shell phases.
Hvar photometry plotted in Fig.~\ref{omiand} shows regular
cyclic changes with a possible period of 2525~d.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{oand-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{oand-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{oand-ub.pdf}}
\caption{The \ubv\ time variations of $o$~And.}
\label{omiand}
\end{figure}

\bigskip
{\tt KX And = HD 218393} \ \ The light variability of this object was discovered
from Hvar photometry \citep{kxand01}. A large spectroscopic and photometric study,
based also on Hvar photometry, was published by \citet{zarf14}.
These authors found periodic RV, light and colour variations with
a 38\fd919 period and suggested tentatively that the object
could be an interacting binary. \citet{floquet95} and \citet{tolja98}
obtained a clear circular-orbit period based on the sharp lines of G8II
secondary component, with a~semiamplitude of 86~\ks, proving thus definitively
the binary nature of the object. \citet{stagg88} and \citet{kreso89}, who used
also Hvar photometry, reported possible short periods of 0\fd476 and 0\fd353,
respectively, after the removal of orbital changes. Such a removal is not
straightforward, however, since there are cycle-to-cycle changes in
the orbital light curve.
Complete Hvar photometry is in Fig.~\ref{kxand}. No secular changes are seen.
The orbital light curves are in Fig.~\ref{kxand-ph}.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kxand-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kxand-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kxand-ub.pdf}}
\caption{The \ubv\ time variations of KX~And.}
\label{kxand}
\end{figure}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kxphd-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kxphd-b.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kxphd-u.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kxphd-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kxphd-ub.pdf}}
\caption{The 38\fd919 orbital light curve of KX~And
based on Hvar (black) and transformed Hipparcos \hp\ (red)
observations.}
\label{kxand-ph}
\end{figure}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ubbvpos.pdf}}
\caption{The \ub\ versus \bv\ diagram for several Be stars with
a positive correlation between the brightness and emission-line strength.
Also shown are the reddening line and the photometric sequences
corresponding to the main sequence stars (V) and
to bright supergiants (Ia) \citep[adopted from][]{golay74}.}
\label{ubbvpos}
\end{figure}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ubbvinv.pdf}}
\caption{The \ub\ versus \bv\ diagram for several Be stars with
an inverse correlation between the brightness and emission-line strength.
The same notation as in Fig.~\ref{ubbvpos} is used.}
\label{ubbvinv}
\end{figure}

\section{Discussion}
Our systematic observational effort and monitoring of a~representative sample
of fifty nine bright early-type emission-line stars from the Northern Hemisphere
(down to declinations of about $-20^\circ$) helped to realize that virtually
all Be stars are light and colour variables and to the recognition of their
characteristic timescales. With the exception of several dedicated observational
campaigns, our photometry is more suited to the detection of changes
on long time scales.

The cases of objects like $\beta$~Lyr or V1507~Cyg show how the duplicity or
multiplicity of individual emission-line objects can lead to a large variety
of observational effects. In particular, the Roche-lobe filling brighter
but usually less massive secondaries in the binaries with large-scale mass
transfer can have spectra, which closely mimic the supergiant or bright giant
spectral classification but have masses significantly lower than 10~\ms.

{\bf In Table~\ref{tab03} binary stars with known orbits are identified by
their orbital period, eccentricity and source of the binary orbit. We note
that the confirmed binaries represent only about one third of the whole sample
of 106 objects.}  It is also notable that the vast majority of known binaries
with the Be primary has circular orbits. This seems to indicate
that these systems have undergone
large scale mass transfer sometimes in their evolution, which helped to
circularize their orbits. For V1507~Cyg, which has an eccentric orbit,
\citet{davidge2023} argued that the eccentricity was caused by a~third body
in the system. This could also be the case of BU~Tau, a member of the Pleiades
cluster, where the encounter with another body seems quite probable. Also
{\bf the two other objects with  probably eccentric orbits, V832~Cyg, and V1931~Cyg,
are member of a~relatively close visual systems WDS~J20598+4731, and
WDS~J21012+4609, respectively.}

Our sample indicates that the least variable Be stars are found among objects
with spectral types later than B5. \citet{shokry2018} -- who studied a~different
sample of Be stars -- arrived at a similar conclusion. However, this is
not a general rule. Objects like V839 Her, V744 Her or BU Tau actually show
large secular changes. That might be related to the fact that all of them
are known binaries.

{\bf In Table~\ref{types}, the variability patterns found for more frequently
observed hot emission-line objects are summarised. Although rich, our sample
is not numerous enough for truly statistical evaluation. However, some
preliminary conclusions can be drawn.}

First, it is seen that rapid variability is observed for the vast majority of
cases. There are, however, notable exceptions, such as 17~Tau, which was found to be
constant on shorter time scales {\bf on the level of accuracy of good
ground-based photometries. Yet, even this object seems to be variable
on sub-millimag level provided by TESS space photometry.}

The existence of variations on the very long {\bf LTCV} time scale
{\bf was probably detected in twelve cases. In eight cases a slow secular decrease
of brightness is found, while the slow increase is seen in only four cases.
The existence of this type of variability implies that it might not be reliable}
to estimate the true stellar radius from the dereddened
$V$ magnitude, bolometric correction and measured parallax since even
the observed $V$ magnitude outside the emission-line episodes varies
with time and probably refers to the remaining stellar pseudo-photosphere.

We note that in some cases of secular changes, the amplitude of variations
in the \bv\ index is larger than that in \ub, while in other objects it is
just the opposite.

{\bf We also want to point out that the models of Be star disks should not be
based only} on satellite photometries with their
very broad passbands. Cases of stars like V744~Her, V1294~Aql or BU~Tau show
that the variations in the yellow, blue, and ultraviolet parts of the stellar spectrum
can be quite different, and these differences are inevitably affecting
the variability patterns recorded with the very broad passbands of
the MOST \citep{walker2003}, TESS \citep{tess}, and largely also
BRITE \citep{weiss2014} satellites.

{\bf LTEM variability was detected in about a~half of all monitored objects.
From these, about 34~$\%$ cent showed the positive correlation between the brightness
and emission-line strength, and only 10~$\%$ showed the inverse correlation.
In two cases, alternation between the two types of correlation was found.}

In Figures~\ref{ubbvpos} and \ref{ubbvinv} we show examples of positive
and inverse correlations between brightness and Balmer-line emission
strength as defined in Sect.~3. We note that besides the basic type, the inverse
correlation is also observed on the time scale of binary orbital motion
for binaries observed not far from the equator-on configuration. This is
obviously due to varying projection effects of circumstellar matter as
these binaries revolve around each other. This is the case of KX~And,
UX~Mon or RX~Cas in Fig.~\ref{ubbvinv}.





%{\onecolumn
%\longtab{
%\begin{flushleft}
\begin{table*}
	\tiny
\caption{Types of variations, as defined in Sect.~3, of 59 hot emission-line
objects more frequently observed at Hvar}\label{types}
	\begin{tabular}{rrrcccccccc}
\hline\hline
	Star   &HD/BD &    No. &LTEM&LTCV&MTBIN&VLTV&RAV\\
\hline
	$\omicron$ Cas&   4180& 895&  p& ? & EL&  no&yes\\
	$\gamma$ Cas  &   5394& 137&  p&yes& ? & inc&yes\\
	V442 And      &   6226& 964&  p& no& no&  no&yes\\
	$\varphi$ And &   6811& 504& no&no?& no& dec&?\\
	$\varphi$ Per &  10516& 678&  p&yes&yes& dec&yes\\
	V554 Per      &  14818& 146& no&yes& no&  no&yes\\
	HR 894        &  18552& 118& no& no& no&  no&yes?\\
	RX Cas        &+67 244& 361& no& no& EB&  no&no?\\
	13 Tau        &  23016& 114& no& no& no&  no&no?\\
	17 Tau        &  23302& 367& no&yes& no&  no& no\\
	V971 Tau      &  23480& 265& no&yes& no&  no&yes\\
	$\eta$ Tau    &  23630& 205& no&yes& no& no?& no\\
	BU Tau        &  23862& 469&  i& no& no&  no& no\\
	V960 Tau      &  36576& 392&  p&yes& no&  no&yes\\
	$\zeta$ Tau   &  37202&1100&p+i&yes&yes&  no&yes\\
	$\omega$ Ori  &  37490&  90&  p& no& no&  no&yes\\
	V731 Tau      &  37967& 107& no& no& no&  no&yes\\
	V696 Mon      &  41335& 318& no& no& no& dec&no?\\
	HR 2418       &  47054&  63& no& no& no&dec?&yes\\
	OT Gem        &  58050& 437&  p& no& no&  no&yes\\
	$\beta$ CMi   &  58715& 168& no& no& no&  no&yes\\
	BR CMi        &  61273& 103& no& no& EL&  no& no\\
	UX Mon        &  65607& 152& no& no& EB&  no&yes\\
	HD 81357      &  81357&  93& no& no& EL&  no& no\\
	$\kappa$ Dra  & 109387& 429&  p& no& no& dec&yes\\
	$\vartheta$ CrB&138749& 158& no& no& no&  no&yes\\
	V839 Her      & 142926& 685&  i& no&yes&  no& no\\
	$\delta$ Sco  & 143275&  98&  p& no& no&inc?&no?\\
	$\zeta$ Oph   & 149757& 168&  p& no& no&  no&yes\\
	V744 Her      & 162732&1449&  i& no& no& dec& no\\
	V2048 Oph     & 164284& 164&  p& no& no& dec&yes\\
	V974 Her      & 164447& 183&  p& no& no&  no&no?\\
	$\omicron$ Her& 166014& 182& no& no& no&  no&yes\\
	NW Ser        & 168797& 327& no& no& no&  no&yes\\
	CX Dra        & 174237&1167&  p& no&yes&  no&yes\\
	$\beta$ Lyr   & 174638& 544& no&yes& EB&  no&yes\\
	7 Vul         & 183537& 131&  p& no& no&  no&yes\\
	V923 Aql      & 183656&1620&  i&yes& no&  no&yes\\
	V1294 Aql     & 184279&1709&p+i&yes&yes& dec&yes\\
	V1507 Cyg     & 187399& 193& no& no&yes&  no& no\\
	V1746 Cyg     & 189687& 209& i?& no& no&  no&yes\\
	V1624 Cyg     & 191610& 510&  p& no&  ?&  no&yes\\
	20 Vul        & 192044& 130& no& no& no&  no&yes?\\
	QR Vul        & 192685& 191&  p& no& no&  no&yes\\
	P Cyg         & 193237& 122& no& no& no&  no&yes\\
	25 Vul        & 193911& 124&  ?& no& no&  no&yes\\
       V2119 Cyg      & 194335& 140&  ?& no& no&  no&yes\\
          HR 7843     & 195554& 161& i?& no& no&  no&yes\\
        V1661 Cyg     & 198478& 288& no& no& no&  no&yes\\
         V832 Cyg     & 200120& 849&  p&yes&yes& inc&no?\\
        V1931 Cyg     & 200310& 889&  p& no& no&  no&yes\\
          8 Lac A     & 214168& 151& no& no& no&  no&yes\\
         V360 Lac     & 216200& 424& no&yes& EL&  no&yes\\
           EW Lac     & 217050&1281&  p& no& no& inc&yes\\
         V378 And     & 217543& 267&  p& no& no&  no&yes\\
   $\omicron$ And     & 217675&1636& no&yes& no&  no&yes\\
	   KX And     & 218393&1210& no& no&yes&  no&yes\\
	   KY And     & 218674& 970& no& no& no&  no&yes\\
	   LQ And     & 224559& 590& no& no& no&  no&yes\\
	   \hline
	   \end{tabular}
\tablefoot{Column LTEM: p = positive correlation between the brightness and
emission-line strength, i = inverse correlation between the brightness and
emission-line strength; column MTBIN: EB = eclipsing binary, EL = ellipsoidal
variations, yes denotes either mild sinusoidal variation with the known orbital
period or some peculiar orbital changes; column VLTV: dec = slow secular decrease
of brightness during phases of quiescence, inc = slow secular increase of
brightness during phases of quiescence.}
\end{table*}
%}

\section{Data availability}\label{data}
{\bf As soon as this paper will be published, we shall make the complete all-sky
and differential archives publicly available, together with lists of all stars
observed at Hvar and the instructions
how to extract the individual observations or suitably chosen normals points
for individual stars at
\centerline{\url{https://astro.troja.mff.cuni.cz/projects/hvar50/}}. A~mirror
image will also be provided on a server of the Faculty of Geodesy
of Zagreb University.

   The potential users of these revised Hvar observations should credit
this paper in their future publications.}

\medskip
\begin{acknowledgements}
H. Bo\v{z}i\'c acknowledges financial support from Croatian Science Foundation under
the project 6212 ``Solar and Stellar Variability". P.~Harmanec, M.~Wolf, M.~Bro\v{z},
A.~Opli\v{s}tilov\'a, J.~Jon\'ak, and K.~Vitovsk\'y were supported by
grant GA19-01995S of the Czech Science Foundation. Research of P.~Hadrava was
supported by project RVO~67985815.
Our colleagues J.~Grygar and K.~Pavlovski were associated with the whole
program and carried out a number of observations. Moreover, K.~Pavlovski
helped us to check and correct some of his observations. A~large number
of observations have also been secured by J.~Nemravov\'a-Bene\v{s}ov\'a.
These three colleagues informed us that they do not want to be listed
among the co-authors, which we have to respect.
We credit them for their significant contributions.
Our thanks go to our colleagues and students A.~Arena, J.~Arsenijevi\'c,
R.~Braj\v{s}a, R.~Bro\v{z}, P.~Chadima, D.~\v{C}ikoti\'c, E.~Frle\v{z},
K.~Ho\v{n}kov\'a, Z.~Ivanovi\'c, \v{Z}.~Ivezi\'c, J.~Jan\'\i k,
J.~Jury\v{s}ek, B.~Jovanovi\'c, G.~Lazin, M.~Malari\'c, A.~Muli\'c,
M.~Muminovi\'c, M.~Netopil, D.~Ond\v{r}ich,
D.~Pla\v{c}ko-Vr\v{s}nak, P.~Polechov\'a, \v{Z}.~Ru\v{z}i\'c,
I.~Vince, B.~Vr\v{s}nak, and M.~Zejda who obtained some Hvar
observations reported here and are not included among
the co-authors.  Our special thanks go to J.~Vacek for his design,
maintenance and regular servicing of the Hvar photoelectric photometer.
J.R.~Percy kindly put the archive of his \ubv\ observations of bright
Be stars at our disposal.
{\bf Detailed comments of the referee, Dietrich Baade, helped us to
re-think and restructure different parts of this study.}
The following internet-based resources were
consulted: the SIMBAD database and the VizieR service operated at
CDS, Strasbourg, France; and the NASA's Astrophysics Data System
Bibliographic Services.
%This work has made use of data from
%the European Space Agency (ESA) mission Gaia
%(\url{https://www.cosmos.esa.int/gaia}), processed by the Gaia
%Data Processing and Analysis Consortium (DPAC;
%\url{https://www.cosmos.esa.int/web/gaia/dpac/consortium}).
%Funding for the DPAC has been provided by national institutions,
%in particular the institutions participating in
%the Gaia Multilateral Agreement.
\end{acknowledgements}
\bibliographystyle{aa}
\bibliography{hvar6}


\begin{appendix}

\section{Details on the history of the photometric program at Hvar}\label{apa}
\rm

Over the years, there were essentially three principal observing programs:
(i) systematic monitoring of bright emission-line (Be) stars , (ii) studies of
selected chemically peculiar (CP) stars \citep[e.g.][]{hvar3,kreso79},
and (iii) studies of various interesting binaries
\citep[for instance][]{mayer76,bozic2007,chadima2011}. In this paper, we
present the results of the first program, while the report on the remaining two
programs will be the subject of another study.

  During the first observing season, we primarily tried to cover
a complete light curve of the short-periodic eclipsing binary BR~Cyg
to demonstrate the good performance of the new instrument, and this result was
soon published \citep{hvar1}. In January 1973, Pavel Mayer obtained a nearly
complete light curve of another eclipsing binary, IU~Aur, and confirmed his
1971 discovery that the depths of the light-curve minima of this system
are secularly changing due to the precession of the binary orbit caused by
the presence of a~third body in the system \citep{mayer76}.

From 1980 to 1986 we were coordinating an~international observing campaign,
mainly via the Be Star Newsletter, created and for a~long time run
by M.~Jaschek \citep{hec80ca,hec80cb,hec82c}. We provided the list of Be stars
with the recommended comparisons to interested observers and reported their
observations in the issues of the Be Star Newsletters.

Around 1980, the first studies appeared, in which low-amplitude periodic
or even multiperiodic light variations of some Be stars were detected
\citep{bolton82,percy82,percy83,hec84,balona86}.
Since the typical timescales of such variations were from about 0.3 to 2~d,
observations secured at any single observing station suffered from strong
aliasing problems. This led us to organise a collaborative observing campaign
with the participation of several observers located in very different
geographic longitudes all over the globe. The campaign was carried out in 1983
and was quite successful. The preliminary results were reported by
\citet{stagg85} and the final report was published three years later
\citep{stagg88}.

Gradually, we have started producing detailed studies of individual,
well-observed Be stars of all luminosity classes, which were based not only
on Hvar observations but also on the collection of all available homogenised
photometric and spectroscopic data from various sources. Such studies were
usually carried out in a broad international collaboration. In recent years,
we have also profited from the collaboration with the
colleagues operating large optical interferometers and from comparisons with
theoretical models. This is, for instance, the case of papers like
\citet{hec96,zarf18,zarf21,zarf22,zarf24,zarf26,zarf28,zarf30,zarf31,wolf2021,
mourard2018,broz2021} or \citet{hec2022}, which are discussed in more detail
later, during the discussion of individual well-observed objects.

For curiosity, a~complete list of observers who participated in some
observations at Hvar and the number of usable differential observations
they obtained is given in Table~\ref{observers}.

\begin{table}
%\begin{longtable}{r,r}
\caption{A complete list of Hvar observers and the number
of usable individual differential observations per observer, which they secured
at the Hvar Observatory over the years 1972 -- 2024}\label{observers}
%\hline\hline\noalign{\smallskip}
\begin{tabular}{lrrrrrrrrrrrrrr}
\hline\hline\noalign{\smallskip}
Name of observer&No. of observations\\
\noalign{\smallskip}\hline\noalign{\smallskip}
Hrvoje Bo\v{z}i\'c                   & 46237\\
Petr Harmanec                        &  9530\\
Kre\v{s}imir Pavlovski               &  8674\\
Domagoj Ru\v{z}djak                  &  5636\\
Davor Sudar                          &  5259\\
Jana Nemravov\'a                     &  3945\\
V\'aclav Kocourek                    &  3876\\
Miloslav Tlamicha                    &  3715\\
Petr Hadrava                         &  3485\\
Al\v{z}b\v{e}ta Opli\v{s}tilov\'a    &  2859\\
Franti\v{s}ek \v{Z}\v{d}\'arsk\'y    &  2752\\
Kristian Vitovsk\'y                  &  2064\\
Ji\v{r}\'i Horn                      &  1927\\
Pavel Koubsk\'y                      &  1924\\
Jaroslav Honsa                       &  1902\\
Petr Zasche                          &  1849\\
Miroslav Bro\v{z}                    &  1837\\
Svatopluk K\v{r}\'\i\v{z}            &  1805\\
Marek Wolf                           &  1722\\
Josef Havelka                        &  1607\\
Jana \v{S}vr\v{c}kov\'a              &  1552\\
Michal Zummer                        &  1474\\
Damir \v{C}ikoti\'c                  &  1449\\
Donik Vr\v{s}nak                     &  1436\\
Rostislav Bro\v{z}                   &  1250\\
Juraj Jon\'ak                        &  1036\\
Ji\v{r}\'i Grygar                    &   988\\
Stanislav \v{S}tefl                  &   964\\
Karel Juza                           &   626\\
Adam Harmanec                        &   606\\
Isabelle Piantschitsch               &   582\\
Ivica Skoki\'c                       &   515\\
Jakub Jury\v{s}ek                    &   417\\
Mirjana Malari\'c                    &   373\\
Pavla Polechov\'a                    &   347\\
Milo\v{s} Zejda                      &   334\\
Jan Jan\'\i k                        &   334\\
Pavel Chadima                        &   327\\
Zoran Ivanovi\'c                     &   315\\
David Ond\v{r}ich                    &   302\\
\v{Z}eljko Ru\v{z}i\'c               &   269\\
Dunja Pla\v{c}ko-Vr\v{s}nak          &   218\\
I\v{s}tvan Vince                     &   209\\
Pavel Mayer                          &   177\\
Kate\v{r}ina Ho\v{n}kov\'a           &   166\\
Gordana Lazin                        &   137\\
Ji\v{r}\'i Vacek                     &   136\\
Muhamed Muminovi\'c                  &   136\\
Martin Netopil                       &   121\\
Emil Frle\v{z}                       &    99\\
Jelisaveta Arsenijevi\'c             &    83\\
Amir Muli\'c                         &    68\\
Boro Jovanovi\'c                     &    43\\
Roman Braj\v{s}a                     &    24\\
Aldo Arena                           &    24\\
Bojan Vr\v{s}nak                     &    17\\
\v{Z}eljko Ivezi\'c                  &     6\\
\hline
\end{tabular}
\end{table}


\section{Monitoring the atmospheric extinction at Hvar}\label{apb}
Determination of linear extiction coefficients for every night
of observations, in which the observed standard stars
span a~sufficient range of air masses (at least 0.2),
was a natural part of the data reduction. We found that
the all-sky magnitude residuals during longer observing nights
exhibited small cyclic variations, obviously caused by the
variable linear extinction during the course of the night.
The effect for the low altitude observatory like Hvar is quite
pronounced in some nights but we actually found similar, although
smaller-amplitude effects even at superb moutain observatories like
Sutherland or LaSilla. New versions of HEC22 program allow
removal of these changes with polynomials up to fifth degree.
Figure~\ref{extpol} shows an example of such action for one
Hvar observing night from the 2013 season.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ext0&5-u.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ext0&5-b.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{ext0&5-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kvkbku.pdf}}
\caption{An example of the fit of the residuals of the all-sky magnitudes
during one long summer night by a polynomial of fifth degree in all
three passbands. Original residuals are shown by black dots, those after
the polynomial fit by blue dots. The bottom panel shows the instantaneous values
of the linear extinction coefficients during the course of the night.}
\label{extpol}
\end{figure}

It was also deemed useful to present an overview of seasonal variations in
the extinction, relevant to air pollution at Hvar. Their value exceeds
the astronomical interest and can be valuable for broader community,
ecology studies in particular.

The seasonal variations, plotted in Fig~\ref{extph} and
already noted by \citet{koupav82}, are clearly seen. During the winter seasons,
atmospheric extinction is usually lower as the sea does not evaporate
too much. During the summer seasons, the values of the extinction coefficients
exhibit a large scatter due to local weather changes but on an average
they are much higher then in the winter. Another thing worth noting is
that the minimum values of the seasonal changes do not show any annual
modulation. Such a behavior has also been found at some other sites,
for instance at La~Silla \citep{rufener86} or Grosschwabhausen
observing station \citep{reimann92}). We note that in Fig~\ref{extph} there are some
values of extiction coefficients lying below the general slope of the
minimum extinction, especially for the $U$ band. These extinction
coefficients were usually determined on poor photometric nights or the nights
where only few extinction standard stars had been measured. Of course, such
nights were never used for all-sky photometry.

In Figure~\ref{extjd} we present a time plot of all extinction
coefficients in $U$, $B$ and $V$ passbands, recorded at Hvar Observatory
over the past fifty years. The scatter of the values is mainly caused by
seasonal changes discussed above. Nevertheless, a mild growth of
the extinction can be seen in 1975 and 1982. Such increases are often
related to large volcanic eruptions anywhere in the world.
The first maximum, seen in 1975 may be due to eruption of
the El Fuego volcano in Guatemala (October 1974). We warn, however,
that during the first observing seasons at Hvar, only a limited number
of nights and standard stars suitable for accurate determination of
the extinction were available.

 The next increase of the extinction appeared at the time of eruption
of the El Chiichon volcano (March 1982). The growth of extinction coefficients
after this eruption was also recorded at other observatories
like La Silla \citep{rufener86, burki95}, Jena University Observatory
\citep{reimann92}, or Lowell Observatory \citep{loctho86}. However, the effect
of the powerful eruption of the St. Helens volcano (March 1980) was not
obviously felt at extinction at Hvar. Needless to say, a very small number
of observations was made at that time, however. Also the La~Silla
observations \citep{rufener86} and observations at the Jena University
Observatory \citep{reimann92} did not detected this eruption while at
the Lowell Observatory \citep{loctho86}, the effect was only marginal.
The strong Pinatubo eruption (April 1991) was not covered by Hvar observations
because of the intermission due to war in Yugoslavia.

  A more detailed analysis of the extinction variations at Hvar
and their nature will be published elsewhere. Here we only note that
already \citet{pavlovski79} pointed out that the influence of the
molecular absorption (mainly by $O_3$) is of little effect in the
$UBV$ region. The Rayleigh scattering on air molecules that
depends on wavelength and the air pressure shows a small range
of variability. The most variable component of the extinction
is scattering by aerosols. The Hvar Observatory is a low-altitude
station and in the vicinity of the sea
and is a subject to significant weather changes even within one night.
Obviously the sea spray plays a major role in the large variations
of extinction during the summer seasons. Also occasional forest fires,
quite frequent on the Adriatic coast, may have significant influence on the
measured extinction.


\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{extph.pdf}}
\caption{The seasonal variations of the extinction coefficients at Hvar Observatory.}
\label{extph}
\end{figure}


\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{extjd.pdf}}
\caption{The long-time behaviour of the extinction coefficients at Hvar Observatory
over the past fifty years.}
\label{extjd}
\end{figure}


{\onecolumn
\section{Improved \ubv\ values of the Johnson standards and our
comparison, check, and red standard stars}\label{apc}

Here we provide our compilation of robust mean \ubvr\ values of Johnson standards
derived as robust mean values of individual all-sky observations from night, when
extinction was measured, from the paper by \citet{john66}. Values for the primary
standards are in Table~\ref{primstd}, those for selected secondary standards in
Table~\ref{secstd}. Additionally, we also provide our new \ubv\ standard values
for all comparison, check, and red standard stars used in our observing programs.
These can be used by other photometric observers are usable standards in their future
photoelectric or CCD observations, intended to be transformed to the standard Johnson system.
For standards observed in at least two different seasons and having at least
20 good individual observations, their \ubv\ values are listed in Table~\ref{tab01}.
For less frequently observed standards, their \ubv\ values are provided in Table~\ref{tab02}.

\begin{table*}
\caption[]{The robust mean values of the $V$ magnitude and the $B-V$, $U-B$ and $V-R$ indices
for the ten primary Johnson standards derived from $N$ individual observations published
by \citet{john66}. The rms errors are the rms errors of the mean values.}\label{primstd}
\begin{center}
\begin{tabular}{rrrrrrrrrrrrrrrrr}
\hline\hline\noalign{\smallskip}
Name & HD &$V$& rms &$N$&$B-V$& rms &$N$&$U-B$& rms &$N$&$V-R$& rms &$N$\\
\noalign{\smallskip}\hline\noalign{\smallskip}
$\alpha$ Ari  & 12929&2.0060&0.0033&191& 1.1509&0.0012&192& 1.1260&0.0018&189& 0.8432&0.0039&169\\
HR 875     & 18331&4.2836&0.0020& 77&-0.0551&0.0018& 78&-0.1165&0.0021& 63& 0.0160&0.0029& 63\\
$\beta$ Cnc   & 60267&3.5231&0.0019&223& 1.4830&0.0067&225& 1.7699&0.0020&224& 1.1155&0.0021&197\\
$\eta$ Hya    & 74280&4.2985&0.0012&186&-0.1941&0.0011&186&-0.7446&0.0014&182&-0.0634&0.0021&157\\
$\beta$ Lib   &135742&2.6072&0.0017&143&-0.1073&0.0015&143&-0.3614&0.0017&143&-0.0384&0.0040&128\\
$\alpha$ Ser  &140573&2.6355&0.0014&135& 1.1704&0.0014&137& 1.2509&0.0021&137& 0.8109&0.0048&123\\
$\epsilon$ CrB&143107&4.1527&0.0032&127& 1.2324&0.0012&126& 1.2751&0.0025&126& 0.9012&0.0036&114\\
$\tau$ Her    &147394&3.9052&0.0020&102&-0.1522&0.0019&106&-0.5621&0.0018&103&-0.0822&0.0034& 88\\
10 Lac     &214680&4.8845&0.0014&204&-0.2045&0.0012&204&-1.0464&0.0014&203&-0.0751&0.0018&187\\
HR 8832    &219134&5.5738&0.0019&158& 0.9966&0.0014&158& 0.8861&0.0018&158& 0.8346&0.0023&144\\
\noalign{\smallskip}\hline\noalign{\smallskip}
\end{tabular}
\end{center}
\tablefoot{Of the ten primary Johnson standards, two are reported as variables.
$\eta$~Hya is classified as the $\beta$~Cep pulsator and $\tau$~Her
as a~long-period pulsating star. $\alpha$~Ari, $\beta$~Cnc, $\beta$~Lib;
$\alpha$~Ser, 10~Lac, and HR~8832 are listed as suspected variables.}
\end{table*}

\begin{table*}
\caption[]{The robust mean values of the $V$ magnitude and $B-V$, $U-B$ and $V-R$ indices
derived from $N$ individual observations of seven selected secondary standards
\citep{john54}, with the data taken from \citet{john66}. The rms errors are rms errors
of the mean values.}\label{secstd}
\begin{center}
%\begin{flushleft}
\begin{tabular}{rrrrrrrrrrrrrr}
\hline\hline\noalign{\smallskip}
Name & HD &$V$& rms &$N$&$B-V$& rms &$N$&$U-B$& rms &$N$&$V-R$& rms &$N$\\
\noalign{\smallskip}\hline\noalign{\smallskip}
73 Cet     & 15318&4.2836&0.0020& 77&-0.0551&0.0018& 78&-0.1165&0.0021& 77& 0.0160&0.0029& 63\\
HR 753     & 16160&5.8164&0.0077& 10& 0.9633&0.0039& 10& 0.8074&0.0078& 10& 0.8177&0.0095&  7\\
$\upsilon$ Ori& 36512&4.6215&0.0014&273&-0.2618&0.0099&276&-1.0626&0.0012&274&-0.1217&0.0015&246\\
90 Leo     &100600&5.9495&0.0014&170&-0.1547&0.0011&170&-0.6572&0.0013&168&-0.0589&0.0026&129\\
HR 4550    &103095&6.4411&0.0017&167& 0.7511&0.0012&169& 0.1708&0.0016&167& 0.6637&0.0020&131\\
$\beta$ Oph   &161096&2.7619&0.0023&105& 1.1689&0.0018&107& 1.2408&0.0018&106& 0.8138&0.0033& 88\\
$\gamma$ Oph  &161868&3.7471&0.0024&110& 0.0380&0.0015&111& 0.0348&0.0021&110& 0.0457&0.0042& 91\\
\noalign{\smallskip}\hline\noalign{\smallskip}
\end{tabular}
%\end{flushleft}
\end{center}
\tablefoot{
Of the seven selected secondary standards, $\beta$~Oph is listed as
a suspected variable. HR~4550 got a variable-star name CF~UMa.
It seems that on some rare occasions (one being recorded in
Hipparcos \hp\ photometry) it becomes much fainter than usual.
However, we did not detect such a~decrease during our observations and
used it along with the other standards.}
\end{table*}

%\setcounter{table}{02}
%\longtab{
\begin{longtable}{rccrccccccc}
\caption{\label{tab01} Standard Johnson \ubv\ magnitudes of all comparison, check and
red standard stars used at Hvar, which have at least 20 observations secured in two or
more seasons. The time interval of their observations is also given.}\\
\hline\hline
Star    & HD or BD & JDmin - JDmax & No. of  &$V$&$B$&$U$&$B-V$&$U-B$&\\
name    & number   & -2400000      &obs.     &(mag.)&(mag.)&(mag.)&(mag.)&(mag.)\\
\hline
\endfirsthead
\caption{continued}\\
\hline\hline
Star    & HD or BD & JDmin - JDmax & No. of  &$V$&$B$&$U$&$B-V$&$U-B$&\\
name    & number   & -2400000 &obs.&(mag.)&(mag.)&(mag.)&(mag.)&(mag.)\\
\hline
\endhead
\hline
\endfoot
12 Cas      &  2011&45307.3--60362.4& 117& 5.385\p0.009& 5.397\p0.010& 5.246\p0.012& 0.012&-0.151\\
HR 96       &  2054&57627.5--58887.3&  29& 5.746\p0.009& 5.683\p0.009& 5.370\p0.011&-0.063&-0.313\\
HR 113      &  2626&45216.5--60362.3& 161& 5.940\p0.010& 5.953\p0.011& 5.603\p0.013& 0.013&-0.350\\
HR 189      &  4142&45212.6--60583.5& 847& 5.674\p0.008& 5.549\p0.009& 4.978\p0.011&-0.125&-0.571\\
$\upsilon$1 Cas&  5234&45216.5--59172.4&  94& 4.842\p0.012& 6.057\p0.010& 7.307\p0.011& 1.215& 1.249\\
HR 285      &  5848&56639.2--57957.5&  62& 4.261\p0.012& 5.481\p0.011& 6.798\p0.012& 1.219& 1.317\\
HR 286      &  5914&54015.4--58385.4& 124& 6.488\p0.010& 6.578\p0.011& 6.652\p0.013& 0.090& 0.074\\
HR 289      &  6114&45648.2--60583.5& 615& 6.472\p0.009& 6.721\p0.009& 6.814\p0.010& 0.248& 0.093\\
HR 333      &  6798&54015.4--57656.5&  35& 5.619\p0.011& 5.641\p0.010& 5.661\p0.013& 0.022& 0.020\\
51 And      &  9927&44956.2--60583.5& 925& 3.600\p0.010& 4.881\p0.010& 6.312\p0.011& 1.281& 1.432\\
HR 488      & 10362&54719.5--57779.4& 326& 6.337\p0.009& 6.367\p0.010& 5.942\p0.011& 0.030&-0.425\\
2 Per       & 11291&44956.2--60583.5& 754& 5.713\p0.008& 5.646\p0.009& 5.369\p0.011&-0.067&-0.277\\
HR 561      & 11875&54719.5--57779.4& 257& 6.026\p0.009& 5.996\p0.009& 5.588\p0.010&-0.030&-0.408\\
47 Cas      & 12230&55645.4--57615.5&  21& 5.294\p0.014& 5.617\p0.013& 5.658\p0.015& 0.323& 0.041\\
4 Per       & 12303&44956.2--60583.5& 853& 5.009\p0.008& 4.936\p0.009& 4.631\p0.011&-0.073&-0.305\\
HR 753      & 16160&46324.6--59275.3& 172& 5.815\p0.011& 6.792\p0.010& 7.585\p0.012& 0.977& 0.793\\
HD 16578    & 16578&52584.3--55068.6& 245& 9.029\p0.022& 9.113\p0.015& 9.186\p0.022& 0.084& 0.073\\
24 Per      & 18449&44865.6--59179.4&  48& 4.959\p0.009& 6.191\p0.011& 7.465\p0.015& 1.232& 1.274\\
HD 18962    & 18962&42607.5--60323.3& 163& 7.939\p0.011& 8.547\p0.012& 8.644\p0.014& 0.607& 0.098\\
HD 18992    & 18992&52584.3--55068.6& 190& 8.456\p0.014& 8.545\p0.018& 8.005\p0.018& 0.089&-0.540\\
HD 19193    & 19193&42607.6--58002.6& 109& 8.140\p0.011& 9.396\p0.013&10.696\p0.022& 1.256& 1.300\\
HD 19556    & 19556&55795.5--60323.3&  92& 8.441\p0.012& 9.086\p0.011& 9.215\p0.014& 0.645& 0.129\\
$\omega$ Per   & 19656&44861.6--59106.5& 169& 4.636\p0.010& 5.748\p0.010& 6.792\p0.014& 1.112& 1.044\\
HR 950      & 19736&44861.6--59097.5& 142& 6.160\p0.011& 6.060\p0.009& 5.486\p0.014&-0.099&-0.574\\
HR 1034     & 21278&45307.4--59176.4&  58& 4.999\p0.009& 4.908\p0.012& 4.366\p0.013&-0.092&-0.541\\
4 Tau       & 21686&54116.2--60323.4& 390& 5.150\p0.009& 5.105\p0.010& 5.012\p0.012&-0.045&-0.093\\
HR 1074     & 21856&44988.3--59179.4& 102& 5.902\p0.010& 5.836\p0.011& 5.005\p0.015&-0.066&-0.831\\
6 Tau       & 21933&54116.2--60323.4& 331& 5.774\p0.009& 5.698\p0.010& 5.398\p0.012&-0.076&-0.300\\
HR 1133     & 23193&44988.3--59106.5&  49& 5.615\p0.012& 5.675\p0.013& 5.772\p0.016& 0.060& 0.096\\
16 Tau      & 23288&44863.6--60583.5& 437& 5.476\p0.008& 5.438\p0.009& 5.097\p0.011&-0.038&-0.341\\
18 Tau      & 23324&43140.3--60583.5& 621& 5.674\p0.009& 5.601\p0.010& 5.231\p0.011&-0.073&-0.370\\
43 Per      & 24546&45307.4--59176.4&  30& 5.287\p0.014& 5.704\p0.016& 5.713\p0.018& 0.417& 0.009\\
HR 1229     & 24982&47444.4--59179.4&  44& 6.506\p0.007& 6.613\p0.009& 6.700\p0.010& 0.107& 0.087\\
HR 1243     & 25339&56523.6--60583.5& 223& 5.670\p0.011& 5.689\p0.011& 5.267\p0.013& 0.019&-0.422\\
$\nu$ Tau      & 25490&41691.2--59248.3&  22& 3.906\p0.014& 3.934\p0.013& 3.999\p0.014& 0.028& 0.064\\
37 Tau      & 25604&44863.6--59598.3& 240& 4.381\p0.010& 5.440\p0.009& 6.411\p0.010& 1.058& 0.971\\
$\lambda$ Per  & 25642&48273.3--58888.4&  78& 4.289\p0.006& 4.266\p0.007& 4.258\p0.009&-0.023&-0.008\\
HR 1284     & 26171&56523.6--60583.5& 175& 5.954\p0.012& 5.994\p0.011& 5.917\p0.012& 0.040&-0.077\\
$\omicron$2 Eri& 26965&41691.2--59275.3&  20& 4.426\p0.009& 5.237\p0.011& 5.679\p0.011& 0.812& 0.442\\
HR 1482     & 29526&48273.3--58888.3&  75& 5.674\p0.005& 5.661\p0.006& 5.630\p0.009&-0.013&-0.030\\
59 Per      & 29722&44926.5--58889.4&  37& 5.308\p0.009& 5.324\p0.007& 5.351\p0.010& 0.016& 0.027\\
HD 31894    & 31894&55574.3--58864.4&  49& 8.484\p0.012& 8.529\p0.015& 7.883\p0.016& 0.045&-0.645\\
HR 1644     & 32655&45307.5--59103.5& 205& 6.222\p0.008& 6.667\p0.009& 7.003\p0.012& 0.445& 0.336\\
$\mu$ Aur      & 33641&44926.5--58889.4&  48& 4.826\p0.013& 5.018\p0.022& 5.119\p0.041& 0.192& 0.101\\
HR 1725     & 34332&55858.6--59179.6&  32& 6.233\p0.010& 7.610\p0.011& 9.247\p0.024& 1.376& 1.638\\
$\lambda$ Aur  & 34411&45307.5--59103.5& 260& 4.708\p0.008& 5.317\p0.009& 5.463\p0.011& 0.609& 0.146\\
HR 1738     & 34557&55858.6--59179.6&  24& 5.478\p0.007& 5.593\p0.007& 5.682\p0.010& 0.115& 0.088\\
$\rho$ Aur     & 34759&55858.6--59179.6&  24& 5.223\p0.006& 5.079\p0.007& 4.485\p0.010&-0.144&-0.594\\
HD 35619    & 35619&41691.2--59248.4&  37& 8.533\p0.015& 8.802\p0.012& 8.140\p0.014& 0.269&-0.662\\
HD 35653    & 35653&41691.2--59248.4&  36& 7.451\p0.022& 7.586\p0.018& 6.883\p0.013& 0.135&-0.703\\
33 Ori      & 36351&51512.5--60362.4& 249& 5.458\p0.008& 5.274\p0.008& 4.446\p0.009&-0.184&-0.828\\
HR 1860     & 36589&43136.4--60583.6& 892& 6.203\p0.009& 6.176\p0.009& 5.779\p0.011&-0.028&-0.397\\
HR 1861     & 36591&53744.4--60362.4& 198& 5.341\p0.009& 5.150\p0.009& 4.223\p0.011&-0.190&-0.927\\
HR 1871     & 36741&51512.5--54021.6&  65& 6.584\p0.009& 6.398\p0.009& 5.607\p0.010&-0.186&-0.791\\
121 Tau     & 36819&44902.6--60583.6& 170& 5.380\p0.010& 5.300\p0.009& 4.668\p0.012&-0.080&-0.632\\
126 Tau     & 37711&43136.4--60574.6& 704& 4.847\p0.009& 4.723\p0.010& 4.075\p0.012&-0.125&-0.648\\
51 Ori      & 37984&51512.5--60362.3& 126& 4.930\p0.010& 6.078\p0.010& 7.139\p0.012& 1.147& 1.062\\
$\chi$1 Ori    & 39587&43136.4--60575.6& 467& 4.406\p0.011& 4.992\p0.011& 5.060\p0.013& 0.586& 0.069\\
HR 2154     & 41692&44902.6--52561.6&  72& 5.379\p0.012& 5.252\p0.013& 4.707\p0.016&-0.127&-0.545\\
HR 2205     & 42690&44902.6--59974.4& 369& 5.055\p0.009& 4.860\p0.010& 4.077\p0.012&-0.196&-0.783\\
HR 2218     & 43023&44902.7--59974.4& 201& 5.860\p0.009& 6.764\p0.010& 7.401\p0.013& 0.904& 0.636\\
HR 2248     & 43526&44993.4--58892.4&  67& 6.565\p0.010& 6.450\p0.011& 5.946\p0.015&-0.114&-0.504\\
HR 2300     & 44783&44993.4--58892.5&  75& 6.268\p0.011& 6.193\p0.012& 5.904\p0.018&-0.076&-0.289\\
10 Mon      & 45546&44902.6--59974.4& 271& 5.055\p0.009& 4.876\p0.009& 4.118\p0.011&-0.179&-0.758\\
$\psi$4 Aur    & 47914&45023.4--58925.4&  31& 5.039\p0.010& 6.530\p0.011& 8.372\p0.016& 1.491& 1.842\\
18 Mon      & 49293&44993.4--58892.5&  54& 4.506\p0.010& 5.605\p0.011& 6.637\p0.016& 1.099& 1.031\\
HR 2532     & 49949&45023.4--58925.4&  46& 6.263\p0.010& 6.486\p0.009& 6.614\p0.013& 0.223& 0.128\\
16 Lyn      & 50973&45023.4--58925.4&  24& 4.919\p0.008& 4.948\p0.009& 5.004\p0.013& 0.030& 0.055\\
HR 2645     & 52860&45023.4--58925.4&  26& 6.381\p0.009& 6.342\p0.009& 6.091\p0.011&-0.038&-0.251\\
1 CMi       & 58187&44984.4--59300.4& 515& 5.383\p0.009& 5.488\p0.009& 5.620\p0.011& 0.104& 0.132\\
$\epsilon$ CMi & 58367&44984.4--59300.4& 273& 5.016\p0.010& 6.013\p0.009& 6.791\p0.012& 0.997& 0.777\\
HR 2858     & 59059&44984.4--59300.4& 367& 6.247\p0.009& 6.202\p0.009& 6.102\p0.011&-0.045&-0.100\\
HD 61341    & 61341&55586.5--57792.5&  31& 7.980\p0.014& 8.175\p0.006& 8.276\p0.025& 0.195& 0.101\\
$\zeta$ CMi    & 63975&45056.3--58929.4&  47& 5.134\p0.009& 5.016\p0.011& 4.539\p0.011&-0.118&-0.477\\
HD 65005    & 65005&52655.4--58946.3&  63& 8.003\p0.009& 8.115\p0.012& 8.247\p0.016& 0.111& 0.133\\
HD 65199    & 65199&52655.4--58946.3&  81& 7.682\p0.010& 7.600\p0.009& 7.214\p0.012&-0.082&-0.385\\
HR 3145     & 66141&53026.5--58929.4&  26& 4.414\p0.008& 5.662\p0.011& 6.949\p0.014& 1.247& 1.287\\
30 Mon      & 71155&43143.5--58929.4&  45& 3.903\p0.010& 3.887\p0.008& 3.862\p0.010&-0.016&-0.024\\
39 Cnc      & 73665&41691.6--59276.4&  21& 6.427\p0.013& 7.400\p0.010& 8.225\p0.011& 0.973& 0.825\\
42 Cnc      & 73785&41691.6--59276.4&  25& 6.840\p0.012& 7.042\p0.013& 7.203\p0.010& 0.202& 0.161\\
HR 3608     & 77692&55879.6--58946.4&  32& 6.454\p0.006& 6.491\p0.005& 6.573\p0.006& 0.037& 0.081\\
HD 81772    & 81772&55879.6--58946.4&  43& 8.256\p0.010& 8.570\p0.008& 8.732\p0.012& 0.314& 0.162\\
HD 82861    & 82861&55879.6--58946.4&  61& 7.074\p0.008& 7.218\p0.008& 7.312\p0.007& 0.144& 0.094\\
$\omicron$ Leo & 83808&46095.5--58946.3&  74& 3.523\p0.012& 4.001\p0.011& 4.211\p0.013& 0.478& 0.210\\
$\nu$ Leo      & 86360&46095.5--58946.3&  61& 5.275\p0.013& 5.222\p0.012& 5.101\p0.014&-0.053&-0.121\\
$\lambda$ UMa  & 89021&43143.6--50902.5&  75& 3.456\p0.012& 3.479\p0.010& 3.558\p0.012& 0.022& 0.079\\
43 Leo      & 89962&46095.5--58892.6&  39& 6.105\p0.014& 7.204\p0.010& 8.317\p0.021& 1.099& 1.112\\
49 UMa      & 95310&50854.4--50902.5&  71& 5.082\p0.016& 5.317\p0.010& 5.500\p0.013& 0.236& 0.182\\
51 UMa      & 95934&50854.4--50902.5&  80& 6.031\p0.016& 6.187\p0.011& 6.288\p0.013& 0.156& 0.101\\
55 UMa      & 98353&50854.4--50902.5&  63& 4.774\p0.015& 4.881\p0.010& 4.919\p0.015& 0.107& 0.038\\
HD 104316   &104316&45357.6--58924.5&  77& 6.775\p0.008& 6.867\p0.008& 6.947\p0.013& 0.092& 0.080\\
HR 4609     &104985&44984.7--59733.4& 212& 5.825\p0.013& 6.847\p0.013& 7.693\p0.016& 1.022& 0.846\\
HR 4687     &107193&44984.7--59733.4& 359& 5.492\p0.010& 5.534\p0.011& 5.611\p0.013& 0.042& 0.077\\
HR 5018     &115612&45357.6--59733.4& 165& 6.220\p0.008& 6.165\p0.008& 6.028\p0.009&-0.055&-0.137\\
81 UMa      &118214&41828.4--59025.4&  30& 5.637\p0.009& 5.608\p0.010& 5.544\p0.009&-0.029&-0.064\\
HR 5162     &119476&52444.4--52445.5&  25& 5.845\p0.009& 5.916\p0.010& 5.983\p0.017& 0.071& 0.067\\
HD 119581   &119581&52444.4--52445.5&  23& 6.614\p0.008& 6.738\p0.011& 6.845\p0.016& 0.124& 0.107\\
HR 5216     &120874&41828.4--59025.4&  45& 6.490\p0.011& 6.578\p0.012& 6.641\p0.014& 0.089& 0.063\\
50 Boo      &136849&45916.3--59032.4&  76& 5.393\p0.009& 5.334\p0.008& 5.143\p0.010&-0.059&-0.191\\
HR 5760     &138341&45916.3--59032.4&  97& 6.469\p0.010& 6.667\p0.010& 6.795\p0.013& 0.199& 0.128\\
BD+64 1078  &139549&53491.4--59344.4& 178& 9.141\p0.011& 9.546\p0.012& 9.503\p0.017& 0.406&-0.044\\
BD+64 1079  &139703&53491.4--59344.4& 141& 9.312\p0.011&10.233\p0.011&10.812\p0.016& 0.921& 0.578\\
HD 141930   &141930&45121.4--58564.6&  76& 7.716\p0.008& 7.815\p0.008& 7.916\p0.012& 0.099& 0.102\\
$\lambda$ Lib  &142096&52068.4--60518.4& 100& 5.026\p0.010& 5.035\p0.011& 4.430\p0.014& 0.009&-0.605\\
$\chi$ Her     &142373&42994.3--60467.4& 472& 4.606\p0.008& 5.176\p0.009& 5.185\p0.011& 0.569& 0.009\\
$\lambda$ CrB  &142908&44432.3--59032.4& 129& 5.436\p0.010& 5.781\p0.011& 5.816\p0.011& 0.345& 0.036\\
$\upsilon$ Her &144206&41528.5--60467.4& 720& 4.736\p0.008& 4.642\p0.009& 4.315\p0.011&-0.094&-0.327\\
$\omega$1 Sco  &144470&42241.4--60518.4& 121& 3.935\p0.010& 3.932\p0.012& 3.092\p0.013&-0.003&-0.841\\
$\varphi$ Her     &145389&41536.4--60467.4& 544& 4.249\p0.007& 4.189\p0.009& 3.937\p0.010&-0.061&-0.251\\
HR 6096     &147550&52494.3--54296.4&  80& 6.243\p0.013& 6.301\p0.010& 6.293\p0.013& 0.058&-0.009\\
$\rho$ Oph     &147933&52494.3--56094.4&  21& 4.567\p0.031& 4.802\p0.030& 4.227\p0.031& 0.235&-0.575\\
$\upsilon$ Oph &148357&52494.3--56094.4& 135& 4.636\p0.010& 4.814\p0.013& 4.888\p0.013& 0.178& 0.074\\
16 Oph      &151133&52494.3--54280.5&  50& 6.037\p0.007& 6.017\p0.009& 5.878\p0.011&-0.020&-0.139\\
HR 6278     &152585&52494.3--53192.4&  32& 6.584\p0.012& 6.715\p0.015& 6.829\p0.019& 0.130& 0.114\\
$\epsilon$ Her &153808&52068.3--55120.3&  95& 3.918\p0.010& 3.895\p0.010& 3.804\p0.011&-0.023&-0.091\\
HR 6353     &154445&54275.4--58002.3&  90& 5.623\p0.010& 5.795\p0.012& 5.171\p0.016& 0.172&-0.623\\
HR 6361     &154660&54275.4--58006.3& 363& 6.360\p0.010& 6.572\p0.011& 6.667\p0.014& 0.212& 0.095\\
HR 6367     &154895&54275.4--58002.3& 275& 6.061\p0.009& 6.140\p0.010& 6.159\p0.011& 0.078& 0.019\\
72 Her      &157214&52068.3--55120.3&  95& 5.385\p0.011& 6.005\p0.010& 6.090\p0.011& 0.620& 0.085\\
77 Her      &158414&43313.4--60574.3& 814& 5.851\p0.008& 5.979\p0.009& 6.118\p0.010& 0.128& 0.139\\
30 Dra      &162579&41536.4--60574.3& 710& 5.040\p0.008& 5.073\p0.009& 5.080\p0.010& 0.033& 0.007\\
$\ksi$ Dra     &163588&42241.4--60574.3& 626& 3.745\p0.010& 4.925\p0.010& 6.150\p0.011& 1.180& 1.225\\
HR 6689     &163624&43712.4--59043.5&  77& 5.953\p0.012& 6.078\p0.012& 6.167\p0.017& 0.125& 0.089\\
HR 6690     &163641&45105.5--60535.3& 146& 6.290\p0.009& 6.296\p0.010& 6.062\p0.011& 0.006&-0.234\\
93 Her      &164349&44799.3--60535.4& 356& 4.680\p0.009& 5.923\p0.009& 7.141\p0.010& 1.243& 1.219\\
HR 6719     &164432&45105.5--60535.4& 176& 6.352\p0.009& 6.277\p0.011& 5.520\p0.012&-0.075&-0.756\\
71 Oph      &165760&45105.5--59793.4& 106& 4.663\p0.008& 5.615\p0.009& 6.356\p0.011& 0.952& 0.741\\
102 Her     &166182&44799.4--60535.4& 491& 4.359\p0.008& 4.189\p0.010& 3.392\p0.011&-0.170&-0.797\\
101 Her     &166230&46269.4--60531.4& 343& 5.115\p0.008& 5.278\p0.009& 5.458\p0.010& 0.162& 0.180\\
15 Sgr      &167264&41824.6--59027.5&  32& 5.315\p0.018& 5.388\p0.018& 4.524\p0.020& 0.073&-0.864\\
21 Sgr      &169420&41824.6--59027.5&  41& 4.801\p0.016& 6.122\p0.020& 7.106\p0.025& 1.321& 0.984\\
HR 6900     &169578&44433.4--59044.5& 271& 6.732\p0.010& 6.758\p0.011& 6.561\p0.013& 0.026&-0.197\\
HR 6925     &170137&44433.4--59044.5& 145& 6.003\p0.012& 7.659\p0.012& 9.520\p0.019& 1.656& 1.860\\
HR 6928     &170200&44433.4--59044.5& 313& 5.711\p0.009& 5.687\p0.010& 5.329\p0.014&-0.024&-0.358\\
HR 6997     &172044&49538.5--56899.4&  58& 5.413\p0.006& 5.319\p0.009& 4.805\p0.014&-0.094&-0.514\\
HR 7028     &172883&42993.5--59043.5& 726& 6.015\p0.009& 5.942\p0.009& 5.731\p0.012&-0.072&-0.211\\
HR 7060     &173664&42993.4--59051.5& 891& 6.207\p0.009& 6.282\p0.009& 6.434\p0.013& 0.074& 0.153\\
$\nu$2 Lyr     &174602&49538.5--57973.4& 333& 5.240\p0.008& 5.338\p0.011& 5.438\p0.011& 0.098& 0.100\\
HR 7123     &175225&42998.4--59051.5& 492& 5.523\p0.009& 6.357\p0.010& 6.878\p0.014& 0.835& 0.520\\
HD 175406   &175406&55357.5--56541.4& 292& 8.133\p0.008& 8.395\p0.008& 8.480\p0.011& 0.261& 0.086\\
HD 175469   &175469&55357.5--56541.4& 268& 8.995\p0.010& 9.216\p0.009& 9.306\p0.011& 0.221& 0.090\\
$\gamma$ Lyr   &176437&46969.4--59180.2& 431& 3.252\p0.009& 3.184\p0.013& 3.148\p0.013&-0.068&-0.036\\
HR 7239     &177817&53584.4--59098.3&  75& 6.012\p0.010& 5.993\p0.010& 5.648\p0.010&-0.019&-0.345\\
51 Dra      &178201&42994.4--56094.4&  65& 5.419\p0.018& 5.395\p0.023& 5.328\p0.030&-0.024&-0.067\\
HD 180889   &180889&46238.5--47374.4& 157& 6.907\p0.008& 7.078\p0.010& 7.239\p0.015& 0.172& 0.161\\
HD 181751   &181751&46238.5--47374.4& 108& 6.571\p0.008& 6.500\p0.011& 6.150\p0.015&-0.070&-0.351\\
HR 7378     &182645&53936.5--59098.3&  46& 5.716\p0.010& 5.753\p0.012& 5.424\p0.011& 0.037&-0.329\\
HR 7379     &182678&54280.4--59098.3&  45& 6.719\p0.009& 6.766\p0.008& 6.695\p0.011& 0.047&-0.072\\
HR 7397     &183227&44079.5--60575.4&1566& 5.844\p0.009& 5.861\p0.010& 5.482\p0.013& 0.017&-0.379\\
HR 7404     &183387&44079.5--60575.4& 964& 6.251\p0.009& 7.570\p0.011& 8.931\p0.015& 1.319& 1.361\\
9 Vul       &184606&46679.4--59025.5& 103& 5.008\p0.009& 4.909\p0.010& 4.499\p0.012&-0.099&-0.410\\
HR 7438     &184663&44079.5--60575.4&1137& 6.373\p0.009& 6.782\p0.010& 6.748\p0.012& 0.409&-0.034\\
$\beta$ Sge    &185958&46238.5--58690.6& 111& 4.392\p0.008& 5.426\p0.010& 6.328\p0.016& 1.034& 0.902\\
HD 185978   &185978&54751.2--58402.4& 102& 7.892\p0.011& 8.398\p0.014& 8.493\p0.016& 0.506& 0.095\\
HD 186239   &186239&58324.5--58402.4&  75& 7.362\p0.011& 7.583\p0.011& 7.675\p0.014& 0.221& 0.092\\
HR 7512     &186568&45900.5--58696.5& 597& 6.077\p0.009& 6.003\p0.009& 5.713\p0.011&-0.074& 0.290\\
15 Cyg      &186675&46679.4--60575.4&  88& 4.900\p0.008& 5.837\p0.012& 6.540\p0.013& 0.936& 0.704\\
$\gamma$ Aql   &186791&46969.4--47061.3&  20& 2.717\p0.010& 4.231\p0.013& 5.945\p0.020& 1.515& 1.713\\
17 Cyg      &187013&57210.5--58696.5&  81& 5.007\p0.010& 5.469\p0.012& 5.471\p0.013& 0.462& 0.001\\
HR 7550     &187458&45900.5--58696.5& 722& 6.659\p0.009& 7.083\p0.010& 7.031\p0.012& 0.424&-0.052\\
HD 187664   &187664&54280.5--59082.3&  39& 6.890\p0.011& 7.204\p0.012& 7.435\p0.012& 0.314& 0.232\\
HD 188170   &188170&43027.4--58682.6& 104& 7.352\p0.013& 7.275\p0.015& 6.900\p0.017&-0.077&-0.375\\
13 Vul      &188260&46665.5--59025.5& 160& 4.585\p0.008& 4.536\p0.009& 4.403\p0.012&-0.049&-0.133\\
$\beta$ Aql    &188512&42654.3--57970.5&  21& 3.722\p0.015& 4.576\p0.015& 5.064\p0.012& 0.854& 0.488\\
22 Cyg      &188892&46238.5--60583.3& 362& 4.953\p0.008& 4.862\p0.010& 4.344\p0.013&-0.090&-0.518\\
17 Vul      &190993&44817.4--60583.3& 225& 5.082\p0.010& 4.908\p0.011& 4.228\p0.013&-0.174&-0.680\\
18 Vul      &191747&44432.5--60583.3& 178& 5.529\p0.009& 5.603\p0.009& 5.722\p0.012& 0.074& 0.119\\
19 Vul      &192004&44432.5--60583.3& 118& 5.492\p0.012& 6.907\p0.012& 8.406\p0.016& 1.415& 1.499\\
33 Cyg      &192696&46323.3--59101.4&  59& 4.289\p0.010& 4.398\p0.012& 4.501\p0.014& 0.109& 0.103\\
36 Cyg      &193369&46238.5--60583.3& 273& 5.593\p0.009& 5.633\p0.009& 5.663\p0.013& 0.040& 0.030\\
HR 7815     &194668&44433.5--59087.6& 355& 6.511\p0.009& 6.496\p0.011& 6.447\p0.014&-0.015&-0.049\\
42 Cyg      &195324&46680.4--59077.5&  40& 5.874\p0.010& 6.321\p0.013& 6.531\p0.027& 0.447& 0.210\\
HD 197618   &197618&53578.3--57964.5& 127& 6.995\p0.009& 7.154\p0.009& 7.241\p0.011& 0.159& 0.087\\
$\eta$ Cep     &198149&41528.4--59082.5& 296& 3.426\p0.010& 4.337\p0.011& 4.953\p0.015& 0.911& 0.616\\
HD 198679   &198679&53686.2--57966.4&  23& 6.905\p0.011& 6.852\p0.012& 6.694\p0.015&-0.053&-0.157\\
HD 198692   &198692&51426.4--59101.4&  65& 6.660\p0.011& 7.672\p0.010& 8.483\p0.017& 1.012& 0.811\\
HR 7996     &198820&52165.4--59101.4&  35& 6.436\p0.010& 6.299\p0.007& 5.669\p0.009&-0.138&-0.630\\
HD 199007   &199007&51402.4--59101.4& 154& 7.958\p0.012& 7.907\p0.009& 7.587\p0.011&-0.051&-0.320\\
HD 199311   &199311&46269.5--60583.4& 841& 6.687\p0.008& 6.765\p0.009& 6.857\p0.011& 0.078& 0.092\\
HD 199479   &199479&46269.5--52094.5& 135& 6.845\p0.010& 6.804\p0.009& 6.587\p0.013&-0.041&-0.217\\
HIP 103770  &200270&52500.4--52549.4& 163& 7.768\p0.010& 8.227\p0.012& 8.171\p0.013& 0.459&-0.057\\
HIP 103874  &200468&52500.4--52549.4& 142& 7.862\p0.009& 8.039\p0.012& 8.157\p0.013& 0.177& 0.119\\
HR 8119     &202214&45538.5--59101.4& 130& 5.617\p0.007& 5.737\p0.008& 4.982\p0.010& 0.120&-0.755\\
HD 202349   &202349&44817.4--59082.5& 217& 7.362\p0.010& 7.195\p0.009& 6.222\p0.012&-0.167&-0.974\\
HR 8161     &203245&51067.3--60583.4& 937& 5.762\p0.008& 5.633\p0.009& 5.115\p0.010&-0.128&-0.519\\
$\alpha$ Cep   &203280&46988.4--52494.5&  24& 2.457\p0.010& 2.676\p0.013& 2.786\p0.015& 0.219& 0.110\\
70 Cyg      &204403&44817.4--59082.5& 163& 5.315\p0.007& 5.166\p0.009& 4.505\p0.012&-0.149&-0.661\\
72 Cyg      &205512&44817.4--60531.5& 652& 4.891\p0.009& 5.981\p0.010& 6.991\p0.011& 1.090& 1.011\\
HD 206259   &206259&45155.5--59097.4&  32& 7.534\p0.010& 7.596\p0.011& 7.032\p0.014& 0.062&-0.563\\
HD 206694   &206694&57581.5--57996.5& 157& 8.804\p0.012& 9.319\p0.011& 9.393\p0.014& 0.515& 0.074\\
$\pi$2 Cyg     &207330&42244.5--59097.4&  83& 4.244\p0.008& 4.116\p0.011& 3.404\p0.015&-0.128&-0.713\\
12 Cep      &207528&58740.4--59043.6&  24& 5.517\p0.012& 7.086\p0.011& 9.021\p0.024& 1.569& 1.935\\
HR 8342     &207636&57581.5--58006.5& 168& 6.475\p0.009& 6.466\p0.011& 6.437\p0.012&-0.009&-0.029\\
HD 207793   &207793&45155.5--59087.5&  21& 6.560\p0.010& 6.940\p0.011& 6.424\p0.012& 0.380&-0.516\\
HR 8473     &210873&57581.5--58006.5& 193& 6.389\p0.011& 6.327\p0.011& 6.161\p0.012&-0.063&-0.165\\
2 Lac       &212120&41536.5--59180.2&  88& 4.550\p0.011& 4.445\p0.013& 3.916\p0.014&-0.105&-0.529\\
$\beta$ Lac    &212496&45155.5--59097.4&  40& 4.448\p0.010& 5.458\p0.012& 6.249\p0.016& 1.009& 0.791\\
4 Lac       &212593&41536.5--58740.5& 169& 4.578\p0.011& 4.666\p0.012& 4.314\p0.014& 0.089&-0.352\\
6 Lac       &213420&41929.5--59180.3&  31& 4.509\p0.011& 4.421\p0.011& 3.691\p0.012&-0.088&-0.730\\
$\alpha$ Lac   &213558&46280.5--50341.5&  57& 3.775\p0.010& 3.784\p0.011& 3.802\p0.011& 0.009& 0.018\\
9 Lac       &214454&42996.5--50341.5&  44& 4.641\p0.011& 4.887\p0.010& 5.005\p0.012& 0.246& 0.118\\
15 Lac      &216397&42993.5--46696.5&  54& 4.921\p0.023& 6.536\p0.038& 8.488\p0.034& 1.615& 1.952\\
HR 8708     &216608&46280.5--46696.5&  25& 5.771\p0.009& 6.060\p0.013& 6.170\p0.016& 0.290& 0.110\\
HR 8733     &217101&44432.5--60583.4&1455& 6.175\p0.009& 6.028\p0.009& 5.220\p0.011&-0.147&-0.808\\
2 And       &217782&42993.5--60583.4& 949& 5.108\p0.009& 5.194\p0.010& 5.304\p0.011& 0.086& 0.110\\
3 And       &218031&46664.6--60189.5& 263& 4.662\p0.008& 5.718\p0.010& 6.618\p0.012& 1.056& 0.899\\
1 Cas       &218376&50854.2--51080.5&  40& 4.828\p0.018& 4.792\p0.013& 3.947\p0.027&-0.035&-0.845\\
4 And       &218452&43140.2--60583.4& 892& 5.301\p0.011& 6.724\p0.011& 8.443\p0.015& 1.423& 1.720\\
5 And       &218470&42266.5--60197.6&1203& 5.686\p0.009& 6.116\p0.010& 6.100\p0.012& 0.430&-0.016\\
HR 8806     &218525&43712.5--59077.6&  25& 6.524\p0.011& 6.692\p0.010& 6.892\p0.010& 0.168& 0.200\\
7 And       &219080&45561.5--60197.6& 564& 4.535\p0.008& 4.828\p0.010& 4.861\p0.011& 0.293& 0.033\\
HD 219326   &219326&53241.5--58006.5& 318& 8.361\p0.010& 8.462\p0.011& 8.575\p0.012& 0.101& 0.114\\
HR 8870     &219891&43712.5--59077.6&  54& 6.528\p0.008& 6.689\p0.009& 6.827\p0.011& 0.161& 0.138\\
10 And      &219981&46664.5--51066.6&  25& 5.788\p0.012& 7.321\p0.015& 9.185\p0.019& 1.533& 1.865\\
HD 220073   &220073&52136.6--58006.5& 454& 7.699\p0.009& 8.119\p0.010& 8.122\p0.012& 0.420& 0.003\\
$\iota$ And    &222173&42266.5--51372.4&  25& 4.304\p0.016& 4.205\p0.013& 3.886\p0.021&-0.099&-0.319\\
$\kappa$ And   &222439&42266.5--60583.4& 406& 4.155\p0.009& 4.068\p0.010& 3.849\p0.011&-0.086&-0.220\\
HR 9011     &223229&45297.2--60583.4& 395& 6.085\p0.009& 5.957\p0.008& 5.289\p0.010&-0.127&-0.668\\
HR 9057     &224342&46287.6--58716.4&  56& 6.019\p0.010& 6.739\p0.015& 7.067\p0.021& 0.720& 0.328\\
$\sigma$ Cas   &224572&50854.2--51080.5&  38& 4.880\p0.013& 4.805\p0.010& 4.006\p0.016&-0.075&-0.799\\
HD 224890   &224890&54754.3--55120.6&  34& 6.510\p0.015& 6.694\p0.017& 6.791\p0.019& 0.184& 0.098\\
BD+52 2289  &  --  &42994.4--54294.4&  32& 9.761\p0.017&10.201\p0.051&10.199\p0.059& 0.440&-0.002\\
BD+52 2288  &  --  &42994.4--54294.4&  45& 9.029\p0.018& 9.490 \p.021& 9.441\p0.033& 0.461&-0.048\\
\end{longtable}
%}

%\longtab{
\begin{longtable}{rccrccccccc}
\caption{\label{tab02} The (less accurate) standard Johnson \ubv\ magnitudes of less
frequently observed comparison, check, and red standard stars used at Hvar.}\\
\hline\hline
Star    & HD or BD & JDmin - JDmax & No. of  &$V$&$B$&$U$&$B-V$&$U-B$&\\
name    & number   & -2400000 &obs.&(mag.)&(mag.)&(mag.)&(mag.)&(mag.)\\
\hline
\endfirsthead
\caption{continued}\\
\hline\hline
Star    & HD or BD & JDmin - JDmax & No. of  &$V$&$B$&$U$&$B-V$&$U-B$&\\
name    & number   & -2400000 &obs.&(mag.)&(mag.)&(mag.)&(mag.)&(mag.)\\
\hline
\endhead
\hline
\endfoot
HR 1        &     3&46287.6--46290.6&   9& 6.718\p0.008& 6.783\p0.011& 6.858\p0.014& 0.065& 0.075\\
HD 567      &   567&57634.5--58887.3&  17& 7.221\p0.017& 7.191\p0.024& 6.801\p0.023&-0.029&-0.390\\
$\chi$ Peg     &  1013&42266.5--42278.5&   3& 4.866\p0.011& 6.504\p0.019& 8.350\p0.017& 1.638& 1.846\\
HD 1687     &  1687&56092.5--56092.5&   2& 8.138\p0.003& 9.052\p0.007& 9.648\p0.012& 0.914& 0.596\\
BD+81 13/A  &  3440&46689.6--46696.6&   2& 6.367\p0.009& 6.921\p0.015& 6.905\p0.022& 0.553&-0.016\\
$\nu$ And      &  4727&43136.2--59179.4&  18& 4.541\p0.011& 4.399\p0.009& 3.812\p0.010&-0.142&-0.587\\
20 Cet      &  5112&43140.2--43152.3&   2& 4.738\p0.059& 6.351\p0.023& 8.287\p0.030& 1.613& 1.936\\
$\upsilon$2 Cas&  5395&52488.5--54021.5&  16& 4.639\p0.007& 5.597\p0.008& 6.266\p0.012& 0.958& 0.669\\
BD+81 27/G  &  5817&46689.6--46689.6&   1& 8.429\p0.000& 9.019\p0.000& 9.015\p0.000& 0.590&-0.004\\
BD+81 29/F  &  5905&46689.6--46689.6&   1& 8.519\p0.000& 9.163\p0.000& 9.336\p0.000& 0.644& 0.173\\
BD+81 30/E  &  6006&46689.6--46690.6&   2& 7.968\p0.026& 7.979\p0.028& 7.904\p0.035& 0.012&-0.075\\
80 Psc      &  6763&43140.2--43152.3&   2& 5.514\p0.027& 5.852\p0.001& 5.860\p0.024& 0.338& 0.008\\
BD+80 35/C  &  7471&46689.6--46689.6&   1& 7.209\p0.000& 7.568\p0.000& 7.645\p0.000& 0.359& 0.077\\
BD+80 36/B  &  7505&46689.6--46689.6&   1& 6.688\p0.000& 6.715\p0.000& 6.729\p0.000& 0.027& 0.014\\
$\ksi$ And     &  8207&43136.3--43152.3&   4& 4.880\p0.013& 5.985\p0.019& 7.004\p0.019& 1.104& 1.019\\
$\psi$ Cas     &  8491&45216.5--45216.5&   1& 4.737\p0.000& 5.793\p0.000& 6.734\p0.000& 1.056& 0.941\\
$\upsilon$ And &  9826&46324.6--46324.6&   3& 4.094\p0.002& 4.623\p0.002& 4.691\p0.003& 0.529& 0.068\\
$\tau$ And     & 10205&43136.3--43152.3&   4& 4.970\p0.028& 4.878\p0.013& 4.480\p0.019&-0.091&-0.398\\
107 Psc     & 10476&46324.6--46324.6&   3& 5.267\p0.007& 6.097\p0.009& 6.604\p0.019& 0.830& 0.507\\
HR 502      & 10857&51447.5--51928.3&   9& 6.256\p0.008& 6.323\p0.006& 6.406\p0.008& 0.067& 0.083\\
HR 540      & 11408&51435.6--51928.3&  12& 6.449\p0.005& 6.638\p0.006& 6.751\p0.012& 0.188& 0.113\\
HR 572      & 12005&56898.4--56898.4&   2& 6.056\p0.004& 7.195\p0.003& 8.033\p0.006& 1.140& 0.837\\
50 Cas      & 12216&47371.6--47373.6&   2& 3.991\p0.021& 4.010\p0.028& 4.053\p0.038& 0.019& 0.042\\
HD 13841    & 13841&46679.6--46680.6&   7& 7.365\p0.014& 7.606\p0.009& 6.977\p0.009& 0.242&-0.629\\
HD 14369    & 14369&54018.5--56095.4&  19& 8.097\p0.012& 8.499\p0.015& 8.440\p0.016& 0.402&-0.059\\
$\pi$ Cet      & 17081&43136.4--43152.3&   4& 4.232\p0.023& 4.149\p0.023& 3.724\p0.025&-0.083&-0.425\\
HR 975      & 20193&54026.5--54026.6&   4& 6.311\p0.005& 6.668\p0.008& 6.642\p0.007& 0.357&-0.025\\
$\alpha$ Per   & 20902&47049.5--52494.5&  10& 1.798\p0.011& 2.271\p0.010& 2.655\p0.025& 0.473& 0.383\\
HR 1019     & 20995&54026.5--54026.6&   4& 5.795\p0.009& 5.780\p0.006& 5.623\p0.004&-0.015&-0.157\\
HR 1041     & 21402&54026.5--54026.6&   4& 5.733\p0.002& 5.769\p0.003& 5.836\p0.007& 0.036& 0.067\\
27 Tau      & 23850&52946.5--56508.6&  11& 3.642\p0.008& 3.548\p0.014& 3.196\p0.011&-0.093&-0.352\\
HR 1188     & 23985&43140.3--43152.3&  13& 5.263\p0.031& 5.480\p0.033& 5.562\p0.032& 0.217& 0.083\\
HR 1226     & 24843&52488.5--52488.5&   2& 6.302\p0.005& 7.368\p0.001& 8.273\p0.008& 1.066& 0.905\\
HR 1234     & 25152&52502.5--55454.5&   2& 6.421\p0.003& 6.411\p0.036& 6.328\p0.023&-0.010&-0.084\\
HD 25539    & 25539&55454.5--55454.5&   8& 6.872\p0.017& 6.916\p0.030& 6.323\p0.034& 0.044&-0.593\\
$\pi$3 Ori     & 30652&56540.6--57996.6&  15& 3.186\p0.009& 3.631\p0.014& 3.625\p0.014& 0.446&-0.007\\
$\pi$4 Ori     & 30836&56540.6--57634.6&  10& 3.682\p0.011& 3.513\p0.018& 2.704\p0.010&-0.169&-0.809\\
HD 31617    & 31617&56002.3--56002.3&   3& 7.423\p0.011& 7.432\p0.008& 6.692\p0.007& 0.008&-0.740\\
HR 1617     & 32249&51445.6--51520.5&  46& 4.795\p0.008& 4.617\p0.014& 3.876\p0.016&-0.178&-0.741\\
HR 1621     & 32309&43136.4--43152.3&   4& 4.902\p0.018& 4.858\p0.032& 4.726\p0.026&-0.045&-0.131\\
HD 32328    & 32328&56002.3--56002.3&   3& 7.664\p0.008& 7.616\p0.006& 7.278\p0.007&-0.049&-0.338\\
HR 1671     & 33224&51445.6--51520.5&  25& 5.820\p0.015& 5.735\p0.015& 5.344\p0.017&-0.086&-0.391\\
HR 1697     & 33833&51445.6--51520.5&  12& 5.928\p0.009& 6.869\p0.011& 7.603\p0.012& 0.941& 0.734\\
$\alpha$ Aur   & 34029&47049.5--47058.5&   4& 0.046\p0.017& 0.864\p0.036& 1.312\p0.039& 0.818& 0.448\\
16 Cam      & 34787&45309.6--45697.4&   7& 5.260\p0.007& 5.239\p0.015& 5.195\p0.013&-0.021&-0.044\\
$\beta$ Tau    & 35497&47052.6--47058.5&   2& 1.660\p0.015& 1.516\p0.003& 1.027\p0.004&-0.144&-0.489\\
HR 1833     & 36166&51943.3--53761.3&  19& 5.770\p0.008& 5.575\p0.011& 4.729\p0.009&-0.195&-0.846\\
38 Ori      & 36777&51943.3--51943.4&   3& 5.340\p0.011& 5.397\p0.010& 5.448\p0.013& 0.057& 0.051\\
$\varphi$1 Ori    & 36822&53388.4--53388.4&   3& 4.388\p0.007& 4.246\p0.002& 3.301\p0.007&-0.142&-0.945\\
$\sigma$ Ori   & 37468&58499.4--58499.4&   1& 3.821\p0.000& 3.582\p0.000& 2.566\p0.000&-0.239&-1.016\\
$\ksi$ Aur     & 39283&45308.5--55124.5&  18& 4.983\p0.009& 5.026\p0.014& 5.119\p0.016& 0.043& 0.093\\
$\delta$ Aur   & 40035&45308.5--55124.5&  12& 3.758\p0.009& 4.755\p0.016& 5.587\p0.014& 0.997& 0.832\\
HR 2224     & 43157&45359.3--45360.3&   5& 5.834\p0.006& 5.668\p0.009& 4.991\p0.007&-0.166&-0.677\\
HR 2234     & 43319&45359.3--45360.3&   5& 6.009\p0.013& 6.092\p0.009& 6.172\p0.008& 0.084& 0.080\\
HD 46149    & 46149&53388.5--53388.5&   3& 7.582\p0.001& 7.753\p0.002& 6.995\p0.007& 0.171&-0.758\\
$\psi$2 Aur    & 47174&43140.5--43152.5&   3& 4.802\p0.035& 6.058\p0.012& 7.338\p0.039& 1.256& 1.280\\
$\nu$3 CMa     & 47442&43140.5--43152.5&   3& 4.422\p0.030& 5.547\p0.023& 6.553\p0.044& 1.125& 1.006\\
HD 50109    & 50109&54862.4--54862.4&   4& 9.085\p0.019& 9.079\p0.011& 8.983\p0.017&-0.006&-0.096\\
HD 50169    & 50169&54862.4--54862.4&   3& 9.021\p0.008& 9.023\p0.007& 9.018\p0.007& 0.002&-0.005\\
HD 50346    & 50346&54862.4--54862.4&   3& 8.756\p0.009& 8.680\p0.007& 8.107\p0.007&-0.076&-0.573\\
HD 50669    & 50669&54862.4--54862.4&   3& 8.929\p0.011& 9.625\p0.013& 9.915\p0.008& 0.696& 0.290\\
HR 2572     & 50747&54862.4--54862.4&   3& 5.463\p0.004& 5.616\p0.011& 5.788\p0.006& 0.153& 0.172\\
HD 53035    & 53035&52940.6--52940.6&  13& 7.897\p0.016& 7.827\p0.005& 7.311\p0.037&-0.070&-0.515\\
$\lambda$ Gem  & 56537&45065.3--50865.4&   9& 3.583\p0.008& 3.689\p0.006& 3.818\p0.015& 0.106& 0.129\\
16 Pup      & 67797&43140.6--43152.5&   3& 4.395\p0.005& 4.249\p0.007& 3.653\p0.017&-0.146&-0.596\\
9 Hya       & 74137&43140.6--43152.5&   4& 4.882\p0.011& 5.929\p0.018& 6.845\p0.028& 1.047& 0.916\\
$\iota$ UMa    & 76644&43143.5--43143.5&   1& 3.141\p0.000& 3.351\p0.000& 3.411\p0.000& 0.210& 0.060\\
$\kappa$ UMa   & 77327&43140.6--43152.5&   3& 3.580\p0.006& 3.562\p0.008& 3.596\p0.006&-0.017& 0.034\\
$\vartheta$ Hya   & 79469&43143.5--43143.5&   1& 3.928\p0.000& 3.851\p0.000& 3.728\p0.000&-0.077&-0.123\\
HR 3751     & 81817&56747.3--56747.4&   4& 4.278\p0.008& 5.756\p0.007& 7.470\p0.005& 1.479& 1.714\\
21 LMi      & 87696&43143.6--43143.6&   1& 4.481\p0.000& 4.687\p0.000& 4.738\p0.000& 0.206& 0.051\\
$\alpha$ Leo   & 87901&46095.5--58941.5&  15& 1.341\p0.010& 1.180\p0.022& 0.851\p0.012&-0.161&-0.329\\
56 UMa      & 98839&41824.4--41828.3&   2& 4.997\p0.018& 5.970\p0.033& 6.746\p0.014& 0.972& 0.776\\
$\gamma$ Crt   & 99211&41824.4--41828.3&   2& 3.980\p0.038& 4.190\p0.038& 4.197\p0.042& 0.210& 0.007\\
HD 100972   &100972&41824.4--41828.4&   2& 6.842\p0.002& 6.838\p0.015& 6.843\p0.002&-0.004& 0.004\\
$\zeta$ Crt    &102070&41824.4--41828.3&   2& 4.659\p0.018& 5.625\p0.004& 6.311\p0.030& 0.967& 0.685\\
$\gamma$ UMa   &103287&43143.6--43143.6&   1& 2.452\p0.000& 2.465\p0.000& 2.475\p0.000& 0.013& 0.010\\
HR 4561     &103498&55357.4--55364.4&   8& 7.031\p0.009& 7.053\p0.010& 7.062\p0.009& 0.021& 0.009\\
HR 4572     &103799&55357.4--55364.4&   6& 6.613\p0.009& 7.096\p0.011& 7.082\p0.011& 0.483&-0.014\\
HD 103984   &103984&55357.4--55364.4&   6& 6.931\p0.009& 7.334\p0.008& 7.319\p0.009& 0.403&-0.015\\
$\delta$ UMa   &166205&46969.4--47006.3&   6& 3.312\p0.006& 3.388\p0.013& 3.445\p0.017& 0.076& 0.057\\
$\eta$ Vir     &107259&41691.6--41696.6&   4& 3.861\p0.019& 3.867\p0.027& 3.910\p0.040& 0.006& 0.043\\
6 Dra       &109551&51376.4--51379.4&   5& 4.945\p0.010& 6.278\p0.008& 7.488\p0.014& 1.333& 1.209\\
$\chi$ Vir     &110014&41691.6--41696.6&   4& 4.607\p0.024& 5.794\p0.023& 7.166\p0.042& 1.188& 1.371\\
$\beta$ Com    &114710&42646.3--42654.3&   4& 4.261\p0.022& 4.843\p0.033& 4.899\p0.024& 0.582& 0.056\\
$\eta$ UMa     &120315&46969.4--47006.3&   9& 1.856\p0.010& 1.668\p0.008& 0.995\p0.013&-0.189&-0.672\\
86 UMa      &121409&41828.4--59025.4&  18& 5.740\p0.009& 5.701\p0.012& 5.629\p0.011&-0.039&-0.072\\
$\epsilon$ Boo &129989&52494.4--52494.4&   1& 2.362\p0.000& 3.333\p0.000& 4.064\p0.000& 0.971& 0.731\\
$\chi$ Boo     &135502&52412.4--52500.4&  12& 5.294\p0.007& 5.347\p0.007& 5.418\p0.006& 0.053& 0.071\\
$\gamma$ CrB   &140436&52412.4--52500.4&  12& 3.826\p0.006& 3.827\p0.007& 3.807\p0.005& 0.001&-0.020\\
$\vartheta$ Lib   &142198&41824.4--58946.6&  12& 4.165\p0.011& 5.180\p0.013& 5.978\p0.019& 1.014& 0.799\\
$\nu$ Sco AB   &145502&41824.4--42929.4&   7& 3.998\p0.008& 4.047\p0.009& 3.389\p0.012& 0.049&-0.658\\
$\psi$ Oph     &147700&42241.4--42244.4&   2& 4.439\p0.016& 5.450\p0.001& 6.283\p0.008& 1.010& 0.834\\
59 Her      &154029&52068.3--55120.3&   9& 5.278\p0.010& 5.298\p0.007& 5.342\p0.016& 0.020& 0.044\\
$\alpha$ Oph   &159561&46969.4--47006.4&  11& 2.079\p0.008& 2.227\p0.017& 2.349\p0.017& 0.149& 0.122\\
$\gamma$ Dra   &164058&46969.4--47061.3&  22& 2.227\p0.008& 3.762\p0.010& 5.620\p0.016& 1.535& 1.858\\
HR 6757     &165462&43712.4--43722.4&   8& 6.394\p0.012& 7.435\p0.018& 8.255\p0.017& 1.042& 0.819\\
HD 166101   &166101&57652.3--57652.4&   4& 8.793\p0.027& 9.574\p0.016& 9.798\p0.042& 0.780& 0.224\\
$\delta$ UMi   &166205&56858.5--56858.5&   3& 4.363\p0.004& 4.377\p0.003& 4.417\p0.004& 0.014& 0.039\\
HD 166361   &166361&57652.3--57652.4&   3& 7.454\p0.018& 9.292\p0.015&11.089\p0.153& 1.839& 1.796\\
HD 168443   &168443&57652.3--57652.4&   4& 6.893\p0.005& 7.634\p0.010& 7.924\p0.016& 0.741& 0.289\\
HR 6943     &170650&55121.2--55121.3&  13& 5.877\p0.009& 5.788\p0.015& 5.270\p0.016&-0.089&-0.518\\
HR 6966     &171245&55121.2--55121.2&   2& 5.884\p0.004& 7.365\p0.011& 9.118\p0.022& 1.481& 1.753\\
BD+24 3545  &174369&55124.3--55124.3&   2& 6.750\p0.014& 6.833\p0.001& 6.898\p0.005& 0.083& 0.066\\
$\ksi$2 Sgr    &175775&42241.4--53937.5&   7& 3.537\p0.017& 4.698\p0.024& 5.819\p0.018& 1.162& 1.121\\
$\lambda$ Lyr  &176679&56491.4--56639.2&   2& 4.961\p0.001& 6.414\p0.018& 8.082\p0.012& 1.454& 1.668\\
$\zeta$ Aql    &177724&46969.4--47061.3&  18& 2.990\p0.009& 2.996\p0.011& 3.002\p0.014& 0.006& 0.006\\
$\beta$1 Cyg   &183912&46689.3--46689.4&   2& 3.067\p0.003& 4.189\p0.001& 4.864\p0.007& 1.123& 0.674\\
$\kappa$ Aql   &184915&42647.3--42654.4&   3& 4.938\p0.017& 4.925\p0.015& 4.069\p0.016&-0.013&-0.855\\
HD 187411   &187411&57615.4--59082.4&  13& 8.105\p0.009& 8.471\p0.010& 8.601\p0.013& 0.366& 0.130\\
23 Vul      &192806&43027.4--50341.5&  13& 4.511\p0.009& 5.780\p0.007& 6.920\p0.015& 1.268& 1.140\\
39 Cyg      &194317&46688.4--46695.4&   4& 4.431\p0.024& 5.781\p0.017& 7.297\p0.019& 1.351& 1.516\\
13 Cap      &196348&43712.4--43722.5&   2& 6.791\p0.011& 8.017\p0.008& 9.292\p0.012& 1.227& 1.274\\
71 Aql      &196574&41528.4--59179.3&  13& 4.337\p0.009& 5.270\p0.008& 5.954\p0.012& 0.933& 0.684\\
HR 7922     &197226&47017.4--47022.4&   7& 6.521\p0.006& 6.396\p0.008& 5.907\p0.017&-0.125&-0.489\\
$\epsilon$ Aqr &198001&41528.4--41528.4&   2& 3.775\p0.022& 3.779\p0.011& 3.790\p0.037& 0.003& 0.012\\
HD 198424   &198424&47017.4--47022.4&  12& 7.510\p0.008& 7.410\p0.012& 6.980\p0.020&-0.100&-0.431\\
56 Cyg      &198639&51715.4--51715.4&   3& 5.068\p0.005& 5.266\p0.010& 5.370\p0.012& 0.198& 0.104\\
HD 198793   &198793&53686.2--53686.2&   3& 7.141\p0.003& 7.058\p0.005& 6.592\p0.007&-0.082&-0.466\\
HR 8029     &199661&53686.2--53686.2&   3& 6.237\p0.004& 6.075\p0.006& 5.350\p0.003&-0.162&-0.725\\
HD 199781   &199781&51376.3--51380.5&   5& 8.335\p0.026& 8.789\p0.041& 8.778\p0.075& 0.453&-0.010\\
HD 199890   &199890&51715.4--51715.4&   3& 7.518\p0.001& 7.422\p0.007& 7.044\p0.012&-0.097&-0.378\\
HD 199986   &199986&51377.4--58351.5&   8& 7.052\p0.038& 7.488\p0.410& 7.755\p0.721& 0.436& 0.267\\
HR 8049     &200205&46691.4--46691.4&   2& 5.537\p0.004& 6.964\p0.004& 8.562\p0.007& 1.427& 1.599\\
$\vartheta$ Cap   &200761&42607.5--43722.5&   2& 4.062\p0.005& 4.057\p0.010& 4.058\p0.016&-0.005& 0.001\\
HR 8107     &201836&43027.4--43027.4&   6& 6.452\p0.007& 6.445\p0.014& 6.064\p0.015&-0.007&-0.381\\
HR 8136     &202654&43027.4--43027.4&   5& 6.445\p0.014& 6.308\p0.009& 5.626\p0.011&-0.137&-0.682\\
1 Peg       &203504&42237.4--42237.4&   1& 4.104\p0.000& 5.195\p0.000& 6.250\p0.000& 1.091& 1.055\\
HR 8185     &203644&51371.4--51371.5&   4& 5.688\p0.005& 6.787\p0.015& 7.825\p0.019& 1.099& 1.038\\
$\kappa$ Cap   &206453&42607.6--43713.6&   3& 4.716\p0.024& 5.581\p0.022& 6.113\p0.021& 0.864& 0.532\\
HD 209932   &209932&55452.3--55460.5&  52& 6.522\p0.012& 6.490\p0.015& 6.350\p0.016&-0.032&-0.140\\
BD+48 3613  &210119&52940.2--52940.4&  14& 8.328\p0.009& 8.426\p0.009& 8.505\p0.016& 0.098& 0.078\\
HD 210387   &210387&55452.3--55460.5&  33& 6.799\p0.013& 6.761\p0.014& 6.486\p0.016&-0.038&-0.275\\
35 Peg      &212943&42266.4--42278.4&   3& 4.765\p0.010& 5.811\p0.022& 6.682\p0.023& 1.046& 0.871\\
HR 8606     &214240&43143.2--43326.6&   7& 6.276\p0.016& 6.227\p0.012& 5.664\p0.010&-0.049&-0.563\\
11 Lac      &214868&42607.6--42609.6&   2& 4.492\p0.006& 5.828\p0.001& 7.287\p0.003& 1.335& 1.459\\
HR 8654     &215359&58700.6--58700.6&   3& 5.921\p0.008& 7.442\p0.004& 9.139\p0.015& 1.521& 1.698\\
$\alpha$ Peg   &218045&46988.4--47061.3&  23& 2.482\p0.009& 2.441\p0.011& 2.389\p0.014&-0.041&-0.052\\
HD 219430   &219430&42278.5--42278.5&   1& 4.165\p0.000& 5.262\p0.000& 6.287\p0.000& 1.097& 1.025\\
$\psi$1 Aqr    &219449&42237.6--42237.6&   1& 4.268\p0.000& 5.403\p0.000& 6.415\p0.000& 1.135& 1.012\\
HR 8857     &219668&43712.5--43722.5&   5& 6.505\p0.006& 7.547\p0.016& 8.539\p0.014& 1.042& 0.991\\
72 Peg      &221673&42237.6--42237.6&   1& 5.010\p0.000& 6.390\p0.000& 8.007\p0.000& 1.380& 1.617\\
$\omega$2 Aqr  &222661&42607.6--43713.6&   3& 4.454\p0.022& 4.385\p0.024& 4.248\p0.032&-0.069&-0.137\\
BD+37 3873  &228897&55121.3--55124.4&  13& 8.923\p0.008& 9.060\p0.009& 8.590\p0.013& 0.137&-0.470\\
HD 277197   &277197&55851.5--55858.7&  11& 9.490\p0.013& 9.557\p0.015& 9.018\p0.027& 0.067&-0.539\\
HD 339764   &339764&55454.4--55454.4&   1& 9.599\p0.000& 9.688\p0.000& 9.779\p0.000& 0.089& 0.091\\
ADS 10347B  &  --  &54275.4--54294.4&  15& 9.630\p0.062&10.267\p0.097&10.407\p0.113& 0.637& 0.140\\
ADS 10347AB &  --  &54281.5--57948.4&  15& 6.334\p0.033& 6.581\p0.068& 6.702\p0.131& 0.247& 0.121\\
BD+43 1166C &  --  &55596.4--56002.3&   5&10.720\p0.338&11.402\p0.423&11.712\p0.393& 0.682& 0.310\\
BD+67 248   &  --  &55851.4--55858.6&  11& 9.024\p0.012& 9.752\p0.013&10.463\p0.012& 0.728& 0.711\\
BD+68 220   &  --  &55858.6--55858.6&   2& 9.146\p0.000& 9.752\p0.010& 9.802\p0.002& 0.606& 0.050\\
BD+43 1168  &  --  &56002.3--56002.3&   3& 9.390\p0.011&10.311\p0.011&10.579\p0.014& 0.920& 0.269\\
\end{longtable}
%}

\twocolumn
\section{Brief discussion on the remaining more frequently observed hot
emission-line stars}\label{apd}

{\tt $\gamma$~Cas = 27 Cas = HD 5394} This one of the brightest Be stars
in the sky has been subject of more than 1100 studies. It is now known to be
a spectroscopic binary with a 203\fd52 orbital period
\citep[][and references therein]{zarf20,zarf29,borre2020}, with a low-mass companion,
probably a white dwarf \citep{gies2023}. Its light variations are characterised
by long-term changes with positive correlation and rapid changes with periods
1\fd216, and 0\fd4033 \citep[][and references therein]{hec2002,borre2020,smith2021}.
Observations of this star at Hvar are not very numerous, mainly because of the
fact that it was necessary to use a lower high voltage due to its brightness
to avoid saturation. They are shown in Fig.~\ref{gamcas} and only complement
the secular brightness changes documented in \citet{hec2002} and \citet{smith2021}.


\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{gcas-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{gcas-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{gcas-ub.pdf}}
\caption{The \ubv\ time variations of $\gamma$~Cas.}
\label{gamcas}
\end{figure}

\bigskip
{\tt V554 Per = 10 Per = HD 14818}  This object is classified as B2Ia but \citet{wes2022}
observed its \ha emission, reminiscent of a P~Cyg profile. Its light variability was
reported by \citet{alvschu81} and \citet{hvar5} but the variable-star name V554~Per
was assigned to it only on the basis of Hipparcos photometry by \citet{namelist74}.
Hvar and Hipparcos photometry is shown in Fig.~\ref{v554per}. The brightness and colour
variations are characterized by cyclic changes, with no obvious secular trend.
A formal period analysis of combined Hvar and Hipparcos $V$ photometry suggests
a possible period of 237\fd082, but with a large scatter around the mean phase curve.



\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v554p-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v554p-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v554p-ub.pdf}}
\caption{The \ubv\ time variations of V554~Per.}
\label{v554per}
\end{figure}


\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{hr894-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{hr894-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{hr894-ub.pdf}}
\caption{The \ubv\ time variations of HR~894.}
\label{hr894}
\end{figure}

\bigskip
{\tt HR 894 = HD 18552} \citet{polidan76} tentatively suggested that this object
is a B8V+gG9 binary, based on the calcium triplet emission in the infrared spectra.
However, the presence of a cool giant companion has never been confirmed.
The object exhibits only mild variations of the \ha emission over a long interval of
spectral observations and Hvar photometry shows no significant light or colour changes
(see Fig.~\ref{hr894}). We therefore did not continue to observe it.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{rxcas-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{rxcas-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{rxcas-ub.pdf}}
\caption{The \ubv\ time variations of RX~Cas.}
\label{rxcas}
\end{figure}

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{rxph-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{rxph-b.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{rxph-u.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{rxph-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{rxph-ub.pdf}}
\caption{The magnitude and colour phase diagrams for RX~Cas based on the
quadratic ephemeris of \citet{mennick2022}.}
\label{rxcas-ph}
\end{figure}

\bigskip
{\tt RX Cas = BD+67 244} This object is an interacting Be+G3III binary with
a 32\fd3 period secularly increasing in time and with a~cyclic brightness
variation at light maxima on a scale of about 500 days \citep{struve44,
gaposchkin44,kriz80,andersen89}. \citet{mennick2022}
analysed more than a century of photometric observations, derived an~improved
quadratic ephemeris, and studied the long cycle of brightness variations at
maximum light. To the best of our knowledge, there is no reliable RV curve
of the Be primary hidden in the dense shell.
The first part of Hvar photometry has already been used in \citet{kriz80}
study. The complete set of Hvar observations is shown in Fig.~\ref{rxcas}.
In this case, we have not included Hipparcos photometry since the \bv\
index of the binary varies significantly with the binary orbital phase and
with the long cycle and the transformation to Johnson $V$ would
deserve a more sophisticated treatment. Our new detailed study of the binary
is under consideration and here we only show the phase coverage based on
the complete set of Hvar data in Fig.~\ref{rxcas-ph}. The
phase coverage is seen to be quite good. We note that the secondary minimum is absent
in the $U$ magnitude. However, a mild light decrease near orbital
phase 0.8 is observed in all three passbands.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{13tau-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{13tau-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{13tau-ub.pdf}}
\caption{The \ubv\ time variations of 13~Tau.}
\label{13tau}
\end{figure}

\bigskip
{\tt 13 Tau = HD 23016} is a Be star that is only projected in the sky to the
Pleiades cluster but is not its member. \citet{barnsley2013} provide some evidence
of a mild change in the \ha emission strength (equivalent range from 4.0 to 5.7~\AA)
over the time interval from JD~2451029 to 2455524. Hvar photometry shown in
Fig.~\ref{13tau} provides little evidence for a significant light variability
over a time interval of nearly 10000 days.

\bigskip
{\tt V971 Tau = 23 Tau = HD 23480}
For this bright Be star from the Pleiades cluster, also known as Merope,
\citep{mcnamara85, mcnamara87} found rapid variation
with the 0\fd490 period and an amplitude of several thousands of magnitude.
\citet{white17} using data from the Kepler mission confirmed this periodicity and
suggested the existence of several closely spaced periods. Despite
a very small amplitude of rapid changes, the Hvar photometry is able to resolve periodic variations with the 0\fd490 period. The Hvar photometry presented
in Fig.~\ref{v971tau} indicates that the small light variability is dominated by
these rapid changes but also reveals mild long-term variations, best seen in
the \ub\ index.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v971t-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v971t-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v971t-ub.pdf}}
\caption{The \ubv\ time variations of V971~Tau.}
\label{v971tau}
\end{figure}

\bigskip
{\tt $\eta$~Tau = 25 Tau = HD 23630} This brightest Be member of the Pleiades
cluster, also known as Alcyone, is a visual multiple system
WDS~03475+2406. Figure~\ref{etatau} shows that mild brightness and colour
variations on various time scales are probably present. A cyclic secular
variation can best be seen in the \ub\ index.
It is worth mentioning that \citet{krelow2019} studied the distances to
the brightest stars in the Pleiades derived both from Gaia DR2 release
and from interstellar Ca II lines and concluded that these stars do not form
a~compact cluster but are localized in front of the main Pleiades cluster
at a~distance close to what was derived from Hipparcos. They argued that
the observed spread in the individual distances of the stars in the core of
the cluster could be explained by additional grey interstellar extinction due
to the presence of larger dust grains in the cluster core.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{etat-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{etat-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{etat-ub.pdf}}
\caption{The \ubv\ time variations of $\eta$~Tau.}
\label{etatau}
\end{figure}

\bigskip
{\tt V960 Tau = 120 Tau = HD 36576} The light variability of this star
was discovered at Hvar and was first reported by \citet{pavlovski82}.
As Fig.~\ref{v960tau} shows, the star was monitored quite systematically
at Hvar and has complicated and seemingly irregular variations with a~large
range of 0\m3 in $V$. Its detailed study, which will also include
spectroscopic changes, is in preparation.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v960-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v960-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v960-ub.pdf}}
\caption{The \ubv\ time variations of V960~Tau.}
\label{v960tau}
\end{figure}

\bigskip
{\tt $\omega$ Ori = 47 Ori = HD 37490}
Hvar photometry was obtained mainly as a part of a multisite campaign on the
rapid line-profile and light variability, which resulted in the finding
that both, line-profile and light changes are governed by a single 0\fd97
period \citep{balona2001}. Several episodes of a rapid light increase have
been reported \citep[e.g.][]{guinan84,bergin89} accompanied also by
an~increase of polarization so it is probable that this star has a~positive
correlation between the brightness and \ha emission strength and might be
similar to V442~And. Not very rich Hvar photometry can be seen in
Fig.~\ref{omeori}. It seems that the variations of this star are dominated
by rapid changes; no secular changes are seen.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{omori-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{omori-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{omori-ub.pdf}}
\caption{The \ubv\ time variations of $\omega$~Ori.}
\label{omeori}
\end{figure}

\bigskip
{\tt V731 Tau = HD 37967} A limited set of Hvar observations seems
to show only small and probably rapid changes - see
Fig.~\ref{v731tau}. \citet{sigut2023} estimated the disk inclination
of about 55$^\circ$ for this B4 star.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v731t-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v731t-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v731t-ub.pdf}}
\caption{The \ubv\ time variations of V731~Tau.}
\label{v731tau}
\end{figure}

\bigskip
{\tt OT Gem = HD 58050} Hvar observations were already reported by \citet{bozic82} who
were unable to confirm earlier reports of rapid periodic changes, and by \citet{bozic99}
who found two episodes of light brightening and identified OT~Gem as the object
with a~positive correlation. This agrees with the estimate of the inclination of about
$20^\circ$ to $30^\circ$ by \citet{sigut2023}. \citet{balona2021} analysed small-amplitude
rapid light changes for a number of Be stars using TESS observations. For OT~Gem they
found a period of 0\fd4606 with a non-sinusoidal light curve.
\citet{bartz2022} -- investigating two sectors of TESS photometry -- noted the light
brightenings and changes on longer time scales but
reported also two groups of short periodic changes near 0\fd249 and 0\fd472.
The complete Hvar photometry is shown in Fig.~\ref{otgem} and shows frequent episodes of light
brightenings, similar to V442~And.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{otgem-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{otgem-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{otgem-ub.pdf}}
\caption{The \ubv\ time variations of OT~Gem.}
\label{otgem}
\end{figure}

\bigskip
{\tt $\beta$ CMi = 58715}
\citet{dula2017} announced that the object is a single-line spectroscopic binary
with a 170\fd4 period and a semiamplitude of RV curve of 2.25~\ks. However, \citet{hec2019} --
measuring RVs in many high-dispersion spectra -- were unable to confirm their result
and also \citet{klement2024} did not detect any secondary in their interferometry.
\citet{bozic82} were unable to find evidence of any rapid light variations,
but \citet{saio2007} detected very low light variations in
the MOST satellite photometry, which they interpreted
as g-mode non-radial pulsations. Using wavelet analysis, \citet{hec2019} re-analysed the MOST
photometry and found only one stable period of 0\fd6169, which they tentatively identified
with the star rotational period. \citet{balona2021} found a period of 0\fd6207 with
a non-sinusoidal light curve from TESS photometry.
A rather limited set of Hvar photometry is shown in Fig.~\ref{betcmi}. There is
little evidence of any changes on longer time scales.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{bcmi-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{bcmi-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{bcmi-ub.pdf}}
\caption{The \ubv\ time variations of $\beta$~CMi.}
\label{betcmi}
\end{figure}

\bigskip
{\tt BR CMi = HD 61273} \ \ A detailed spectroscopic and photometric study, based
largely on Hvar photometry, has been published by \citet{zarf30}. BR~CMi was found
to be a B9.5e + G8III semidetached binary in the late phase of mass transfer,
having ellipsoidal light variations and a~slowly increasing orbital period
of 12\fd919. No secular or cyclic light changes were found.

\bigskip
{\tt UX Mon = HD 65607} \ \ This binary was the subject of a very detailed
spectroscopic and photometric study, based also on Hvar photometry
\citep{sudar2011}. It was found to be a~rare binary system observed
in the early stage of mass exchange, before the mass ratio reversal.
Its 5\fd9044 orbital period was found to slowly decrease over time
at a rate of 0.26~s per year. In their discussion
of W~Ser class of binaries and double periodic variables, \citet{mennick2016}
claimed that the period of UX Mon is constant.

\bigskip
{\tt HD 81357 = MWC 859} \ \ This object was found to be a semidetached
binary in the late stage of mass exchange and an~ellipsoidal variable.
Its detailed study was published by \citet{zarf31} and profits from Hvar
photometry. Neither secular nor cyclic light changes were found.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{dsco-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{dsco-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{dsco-ub.pdf}}
\caption{The \ubv\ time variations of $\delta$~Sco.}
\label{delsco}
\end{figure}

\bigskip
{\tt $\delta$ Sco = 7 Sco = HD 143275} This early B star was for a long time
considered a non-variable object and was even recommended as a~$uvby\beta$
standard star. Carefully analysing previous records and using the MAPPIT optical
interferometer, \citet{bedding93} discovered that the object is a~spectroscopic
binary with a highly eccentric orbit and a 10.5~yr orbital period and estimated
that the secondary is for 1\m5$\pm$0\m3 fainter than the primary. This was then
confirmed by several other studies. \citet{tycner2011} published the revised orbit
with a period of 10.817~yr, eccentricity of 0.9380, and orbital inclination of
32.9$^\circ$. \citet{cote93} discovered the presence of \ha emission, and since
then the object has become a~topic of many detailed studies. Large brightness and
colour variations were observed, but no clear proof was found that the occurrence of
\ha emission was related to the periastron passages. In fact, a strong
\ha emission persisted for a long time. The evolution of the disk during three passages in the periastron was discussed by \citet{rast2024}, who also show the light and colour
curve. It is rather surprising that all attempts to find the spectral lines
of the secondary failed.
Hvar observations are presented in Fig.~\ref{delsco} and complement existing
observations from other stations, for instance the \bv\ photometry by
\citet{jones2013}. Note that the object was inevitably observed at large air
masses from Hvar.

\bigskip
{\tt $\zeta$~Oph = 13 Oph = HD 149757} This star was used to be a photometric
standard star in the past. However, several \ha emission episodes were
recorded in its spectra \citep[see][and references therein]{ebbets81}.
This very rapid rotator is also the first Be star for which rapid line profile
variations were discovered by \citet{wyf79}. \citet{tow1} and \citet{tow3}
interpreted the line-profile and small light changes as evidence of
corotating structures revolving with a period of 0\fd64 but many
investigators understand these changes as evidence of non-radial
pulsations. This was also the conclusion of a study based on MOST
satellite photometry \citep{walker2005}. Hvar photometry shows only
small changes and no secular variations, but we warn that the star was
always inevitably observed at large air masses at Hvar.

\bigskip
{\tt V974 Her = HD 164447} \ \ This is a relatively little studied B8e star.
Hipparcos \hp\ photometry \citep{esa97} shows a slow decrease in brightness
over the whole interval of observations. Amateur spectra available in
the BeSS database \citep{neiner2011}, \footnote{\url{http://basebe.obspm.fr/basebe/}}
show that the star lost its Balmer emission in 2020.
Hvar photometry shown in Fig.~\ref{v974her} indicates a brightening
characteristic for a~positive correlation, which is rather rare for
late type B stars.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v974-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v974-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v974-ub.pdf}}
\caption{The \ubv\ time variations of V974~Her.}
\label{v974her}
\end{figure}

\bigskip
{\tt $o$ Her = HD 166014} \ \ This B9.5e star was proposed by \citet{perry87}
as a bright $uvby$H$\beta$ photometric standard. All the \ha spectra in
the BeSS database \citep{neiner2011}, covering the time interval from
2011 to 2024, show  weak double \ha emission not reaching the continuum level.
A limited set of Hvar photometry shown in Fig.~\ref{omiher} is indicative of
small rapid changes and no secular variations.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{omher-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{omher-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{omher-ub.pdf}}
\caption{The \ubv\ time variations of $o$~Her.}
\label{omiher}
\end{figure}

\bigskip
{\tt NW Ser = HD 168797} The Hvar photometry of this B2e star was analysed together
with photometry secured by John~R.~Percy in Toronto to document its rapid and possibly
periodic light changes on time scales from 0\fd4 to 5\fd5 days \citep{percy99}.
No more recent Hvar observations were secured since the publication of that study.
Fig.~\ref{nwser} shows the time plot of all available Hvar and transformed \hp\
observations.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{nwser-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{nwser-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{nwser-ub.pdf}}
\caption{The \ubv\ time variations of NW~Ser.}
\label{nwser}
\end{figure}

\bigskip
{\tt $\beta$ Lyr = 10 Lyr = HD 174638}  This is one of two first discovered
Be stars and a famous 12\fd93 eclipsing and strongly interacting binary with
a complicated structure of circumstellar matter comprising from a disk,
scattering halo and bipolar jets and with a rapidly increasing orbital
period (19~s per year). The history of its investigation
was summarised by \citet{hec2002}. Hvar observations (shown in
a phase plot Fig.~\ref{blyr-ph}) have been secured
in support of several large studies, which also provide summaries
of more recent studies: \citet{hec96,ak2007,mourard2018, broz2021}.
For a long time known cycle-to-cycle variations inside the binary
eclipses are seen there. There is, however, no secular trend in either
the brightness in $V$ passband or in the colour indices.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{blyrph-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{blyrph-b.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{blyrph-u.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{blyrph-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{blyrph-ub.pdf}}
\caption{The orbital light curve of $\beta$~Lyr.}
\label{blyr-ph}
\end{figure}

\bigskip
{\tt V1507 Cyg = HD 187399} This object was known to have \ha emission
since 1921 and was found to be a peculiar binary with an eccentric orbit
and a 27\fd97 orbital period \citep{merrill49}. \citet{hutchings73} interpreted
the object as a binary in the phase before the onset of a~large scale mass exchange
and also discussed a very peculiar orbital light curve, which was later published
in detail by \citet{hill76}. The peculiar shape of the light curve was confirmed
by our Hvar observations \citep{pavlovski79}. \citet{hutchings73} interpreted
the light-curve minima as evidence of shallow eclipses. \citet{davidge2023}
published a very detailed study of the binary and also summarized all other
published studies. Measuring weak emission wings of the
\ion{Si}{ii}~6347 and 6371~\AA\ lines, similarly as several investigators
did for $\beta$~Lyr, he obtained a RV curve of the secondary and estimated
the component masses. He argued that the brighter primary, whose spectrum is
closely reminiscent of the spectra of bright supergiants such as $\beta$~Ori,
is now the less massive star of the system, which lost its mass
toward the secondary during the earlier rapid phase of the mass transfer.
He correctly pointed out that the orbital period of 27\fd9705 \citep{hutchings73}
has remained constant within the limits of the accuracy of its determination
since the study \citet{merrill49}, implying that the system must now be in
the stage of terminal, slow mass transfer. He also speculated about
the possibility that the unusually eccentric (e=0.388) orbit could be
the consequence of perturbation by a third star in the system or fly-by.
\citet{koenig2024} investigated the role of the tidal share energy dissipation
for stars undergoing light brightenings during periastron passage and modelled
such a effect.
  The orbital light curve for the combined Hvar and Hipparcos \hp\
observations transformed to Johnson $V$ is shown in Fig.~\ref{v1507cyg-ph}.
No secular light changes were found.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1507-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1507-b.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1507-u.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1507-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1507-ub.pdf}}
\caption{The 27\fd9705 orbital light curve of V1507~Cyg
based on Hvar (black) and transformed Hipparcos \hp\ (red)
observations.}
\label{v1507cyg-ph}
\end{figure}

\bigskip
{\tt 20 Vul = HD 192044} This is a little studied B8 star. \citet{cop63} reported
broad nebulous \ion{H}{i} and \ion{He}{i} lines and double H$\beta$ and H$\gamma$
emission lines with variable intensity and $V/R$ changes for their photographic
spectra from the years 1938 to 1961 but no details were given. We are not aware
of any systematic study devoted to this object. The available Hvar photometry is shown
in Fig.~\ref{20vul}.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{20vul-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{20vul-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{20vul-ub.pdf}}
\caption{The \ubv\ time variations of 20~Vul.}
\label{20vul}
\end{figure}

\bigskip
{\tt QR Vul = HR 192685} \ \ This object is the brighter component
of a visual binary ADS~13589, the component B located only 0\farcs7
from it and being for 2\m7 fainter. {\bf Its photometric variability was
discovered at Hvar and it was then identified as a Be star
\citep[see][and references therein]{pavlovski83}.}
\citet{balona2021} analysed the TESS observations
and suggested that the light variations can be phased with a 0\fd7918 period
with a non-sinusoidal shape, which they identified with the period of rotation.
The limited Hvar photometry shown in Fig.~\ref{qrvul} is indicative of rapid changes and
occasional light brightenings.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{qrvul-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{qrvul-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{qrvul-ub.pdf}}
\caption{The \ubv\ time variations of QR~Vul.}
\label{qrvul}
\end{figure}

\bigskip
{\tt P Cyg = 34 Cyg = HD 93237}

The brightness variations of this famous luminous blue variable have been monitored
for 5 years with the BRITE satellites, and the results are presented
by \citet{elliot2022}. These authors were unable to find any consistent
periodicities and concluded that the variations are stochastic in nature.
Our limited Hvar observations are shown in Fig.~\ref{pcyg}. The first part
of them had already been reported, along with data from other stations,
by \citet{percy88b}, who were unable to find any strict periodicity.
The Hvar data can complement the existing observations. We note that the variations
in the \ub\ index are larger than those in \bv.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{pcyg-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{pcyg-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{pcyg-ub.pdf}}
\caption{The \ubv\ time variations of P~Cyg.}
\label{pcyg}
\end{figure}

\bigskip
{\tt 25 Vul = HD 193911} \ \ \citet{balona2021} concluded from the TESS
photometry that the small light changes can be reconciled with
a 1\fd890 period with a non-sinusoidal light curve. They identified it
with the star rotational period. Limited Hvar photometry shown in Fig.~\ref{25vul}
is indicative of small-amplitude rapid changes, with possibly some secular
evolution in the \ub\ index.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{25vul-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{25vul-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{25vul-ub.pdf}}
\caption{The \ubv\ time variations of 25~Vul.}
\label{25vul}
\end{figure}

\bigskip
{\tt V2119 Cyg = HD 194335} \ \ \citet{klement2024} obtained an interferometric
circular orbit with a period of 63\fd1475 and summarised the previous studies of this
Be binary with a hot compact companion. Unfortunately, no optical RV curve is available.
Hvar photometry is shown in Fig.~\ref{v2119cyg}. A plot of combined Hvar $V$ magnitude
and the transformed \hp\ magnitude versus the orbital phase does not show a convincing
light curve.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v2119-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v2119-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v2119-ub.pdf}}
\caption{The \ubv\ time variations of V2119~Cyg.}
\label{v2119cyg}
\end{figure}

\bigskip
{\tt V1661 Cyg = 55 Cyg = HD 198478} This star is classified as a B3-4Ia supergiant.
It was a subject of almost 500 studies, so we only refer the readers to the paper
of \citet{kraus2015}, where the studies of spectral and photometric variability
of V1661~Cyg are summarised. These authors tried to study an interplay between
the mass loss and pulsations and decomposed the observed variations in several
observables into a number of periods ranging from 2.7~hours to 22\fd5.
Our limited set of Hvar observations is shown in Fig.~\ref{v1661cyg}. It shows
some variability in $V$ and \bv\ colour but, notably, no variability in the
\ub\ index.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1661-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1661-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v1661-ub.pdf}}
\caption{The \ubv\ time variations of V1661~Cyg.}
\label{v1661cyg}
\end{figure}

\bigskip
{\tt V1931 Cyg = 60 Cyg = HD 200310} \ \ This object is the brighter component
of a visual binary WDS~J21012+4609. \citet{zarf19} discovered that the object
is also a~spectroscopic binary with a 146\fd6 period and analysing photometry including
Hvar observations, they reported large cyclic changes and several possible rapid
periods near 1~d. For comparison, \citet{balona2021} reported a rotational
period of 0\fd6109 with a double-wave light curve from TESS photometry.
The binary was resolved interferometrically and the combined
spectroscopic and astrometric solution gave an inproved period of 147\fd617,
an~eccentric orbit with $e=0.20$, and the orbital inclination of 84.$^\circ$6
\citep{klement2024}.
Hvar photometry plotted in Fig.~\ref{60cyg} shows the pronounced cyclic
light and colour changes on a time scale of years. Surprisingly, its shows
a~clear positive correlation in the \ub\ vs. \bv\ diagram. Is the circumstellar
disk tilted with respect to the binary orbit?

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{60cyg-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{60cyg-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{60cyg-ub.pdf}}
\caption{The \ubv\ time variations of V1931 Cyg.}
\label{60cyg}
\end{figure}

\bigskip
{\tt V382 Cep = 6 Cep = HD 203467} \ \ \citet{krajceva83} analyzed
two sets of RVs from photographic spectra and suggested that the object
could be a close spectroscopic binary with periods of either
2\fd4389 or 0\fd7085. \citet{balona2021} found
a~photometric period of 1\fd658, which they identified with the star
rotational period. Limited Hvar observations are shown in
Fig.~\ref{v382cep}. They show some secular changes but little can
be said about their character.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v382-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v382-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{v382-ub.pdf}}
\caption{The \ubv\ time variations of V382~Cep.}
\label{v382cep}
\end{figure}


\bigskip
{\tt 8 Lac A = HD 214168 = HIP 111546} 8~Lac is
a~multiple system WDS~J22359+3938 composed of components
Aa, Ab, B, C, D, E, F, G, H, I, and J. Component B is also an early B
star with $V=6$\m48 according to a few Hvar observations, in agreement
with the HD catalog. We note that the SIMBAD bibliography gives incorrectly
$V=5$\m67 for 8~Lac~B.  Regrettably, there are no Hipparcos \hp\
observations with error flags 0 or 1 in the Hipparcos catalogue
for either 8~Lac~A or 8~Lac~B.
\citet{balona2021} classify the star as $\beta$~Cep and rotational
variable from TESS photometry and give a rotation period of 0\fd4277.
\citet{klement2024} were unable to resolve the binary in
a~consistent way from their interferometric observations.
Hvar photometry is shown in Fig.~\ref{8lac}. It indicates mild rapid
and secular cyclic changes but little can be concluded about their
character.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{8laca-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{8laca-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{8laca-ub.pdf}}
\caption{The \ubv\ time variations of 8~Lac~A.}
\label{8lac}
\end{figure}

\bigskip
{\tt HR 8682 = HD 216057} \ \ This B8 star has no variable-star name
and the BeSS spectra since 2001 to 2024 show no or only marginal \ha emission
\citep{neiner2011}.
A limited set of Hvar photometry is in Fig.~\ref{hr8682}. No clear evidence
of variability was found.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{hr8682-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{hr8682-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{hr8682-ub.pdf}}
\caption{The \ubv\ time variations of HR~8682.}
\label{hr8682}
\end{figure}

\bigskip
{\tt V360 Lac = HD 216200} This object was found to be a semi-detached
Be+F binary with a~critically rotating secondary and an~orbital period
of 10\fd085 \citep{zarf17, zarf24}. There are also mild cyclic brightness
and colour changes but no slow changes on~the {\bf LTCV} time scale.
Since no new Hvar photometry was obtained since the publication
of \citet{zarf24}, we refer readers to the two cited papers, where also
other studies of this object are summarised.

\bigskip
{\tt KY And = HD 218674}  \ \ Analysing Sept.1982
Hvar photometry, \citet{kreso88} found a~dominant period of 0\fd751
in their data. \citet{stagg88} published the results of
an~international observing spectral and photometric campaign on five
Be stars including KY And. Hvar photometry represented a significant
contribution. While rapid light variations were undoubtedly found
for KY~And, determination of a~consistent period or a~combination
of several periods was not convincing. The most promising period
of 0\fd753 was detectable only in a~part of the data.
Complete Hvar photometry is in Fig.~\ref{kyand}. It is obvious that
the rapid changes dominate, no secular trends are seen.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kyand-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kyand-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{kyand-ub.pdf}}
\caption{The \ubv\ time variations of KY~And.}
\label{kyand}
\end{figure}


\bigskip
{\tt LQ And = HD 224559} This is one of the first Be stars for which the presence
of small-amplitude periodic light variations was found \citep{percy83}. A very detailed
period analysis of numerous photometric observations, including numerous observations
from Hvar by \citet{zarf15} led to the conclusion that that light variations
follow a 0\fd61904 period with a double-wave light curve, which was tentatively
identified with the star rotation period. \citet{jaymie91} analyzed a series
of electronic spectra and reported that the object could be a~single-line spectroscopic
binary with a 7\fd413 orbital period. The RV residuals from the orbital solution
as well as line intensities and equivalent widths were found to vary with
the photometric 0\fd61904 period. It is necessary to add that the binary period
was not confirmed in any of the follow-up studies.
The unpublished \ha spectra and spectra from the BeSS database indicate that during the
past 20 years the star had a strong emission reaching up to 4 times the continuum level.
Hvar photometry is shown in Fig.~\ref{lqand}.

\begin{figure}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{lqand-v.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{lqand-bv.pdf}}
\resizebox{\hsize}{!}{\includegraphics[angle=0]{lqand-ub.pdf}}
\caption{The \ubv\ time variations of LQ~And.}
\label{lqand}
\end{figure}
}


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