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\begin{document}
\IBVShead{5214}{3 January 2002}

\IBVStitle{UBVRI observations of V350 C\lowercase{ep} in the period 1998-2001}


\IBVSauth{SEMKOV, E.H.}

\IBVSinsto{Institute of Astronomy, Bulgarian Academy of Sciences,
72, Tsarigradsko Shose blvd., BG-1784 Sofia, Bulgaria, e-mail: evgeni@skyarchive.org}


\SIMBADobj{V350 Cep}
\IBVStyp{ TTau }
\IBVSkey{photometry}
\IBVSabs{Results from CCD photometric observations of the pre-main sequence }
\IBVSabs{star V350 Cep are present.}
\IBVSabs{A comparison star's sequence around V350 Cep was calibrated in UBVRI bands.}

\begintext

V350 Cep is a pre-main sequence star located in the region of
active star formation NGC 7129. The long-term light curve of V350
Cep resembles the FUOR type stars (Semkov et al. 1999) but its
spectrum is similar to the Classical T Tauri stars (Magakian et al. 1999).
FUOR outburst is a very rare phenomenon and only three stars classified as FUORs
(FU Ori, V 1515 Cyg and V 1057 Cyg) have well-studied light curves.
Therefore, the photometric observations of FUORs and FUOR like stars are important for
theoretical models fitting.

The present photometric data are a continuation of our
investigation of V350 Cep (Semkov 1993; Semkov 1996;
Semkov et al. 1999). Observations were made with tree telescopes:
the 2-m RCC and 50/70/172 cm Schmidt telescopes of the National
Astronomical Observatory Rozhen (Bulgaria) and 1.3-m RC telescope
of the Skinakas Observatory\footnote{Skinakas Observatory is a collaborate project of the University of Crete, the Foundation for Research and Technology - Hellas, and the Max-Planck-Institut f\"{u}r Extraterrestrishe Physik.} of the Institute of Astronomy,
University of Crete (Greece).

Observations with 2-m RCC and 1.3-m
telescopes were made with Photometrics CCD cameras $1024\times1024$
pixels. The size of the pixel is 24 $\mu$m and scale
0\farcs32/pixel for 2-m RCC telescope and 0\farcs5/pixel for
1.3-m RC telescope. All frames are bias subtracted and flat
fielded. Observations with 50/70 cm Schmidt telescope were made
with SBIG ST-8 CCD camera $1530\times1020$ pixels. The size of the
pixel is 9 $\mu$m and scale 1\farcs1/pixel. CCD frames obtained with the
50/70 cm Schmidt telescope were dark
subtracted and flat fielded. All frames ware taken through a standard
Johnson-Cousins set of filters. Aperture photometry was performed using
IRAF/DAOPHOT\footnote{IRAF is distributed by the NOAO, operated by the Association of Universities for Research in Astronomy Inc., under contract with the NSF.} routines.

Pogosyants (1991) calibrated a sequence of comparison stars in the
field of V~350~Cep. This sequence is not suitable for CCD photometric observations
because the stars are calibrated only in BV bands using photographic observations.
In order to facilitate transformation from instrumental measurement to the standard
system nine stars from Pogosyants's sequence has been calibrated in UBVRI bands.
Calibration was made during ten clear nights, five with 2-m RCC telescope and
five with 1.3-m RC telescope.
Standard stars from Landolt (1992) were used as reference.
Table 1 contains the photometric data for UBVRI comparison sequence. The corresponding
mean errors of the mean and number of observations for each star are listed also.
The finding chart of the comparison sequence is present in Fig. 1. The chart is a
reproduction from V frame obtained with the 1.3-m RC telescope on July 15, 2001.
North is at the top and east is to the left. The original designations of stars
given by Pogosyants (1991) are preserved.



The results from our CCD photometric observations are given in Table 2.
The table contains
the Julian Date, the V magnitude, $U-B$, $B-V$, $V-R$ and $V-I$ indices and the used telescope.
The mean value of instrumental errors are 0\fmm015(I) and 0\fmm019(V) for observations made with
Photometrics CCD cameras and 0\fmm022(I) and 0\fmm029(V) for observations made with
ST-8 CCD camera.
Fig. 2 shows the long-term B/pg- and V-band light curves of V350 Cep from all available
photometric observations.
In the figure open triangles denote our CCD photometric presented in
this paper. Other symbols are as in Semkov et al. (1999).
As seen from Fig. 2 the magnitude of V350 Cep during the period of observations
is still near to the maximum value. Therefore, the star has been keeping its maximum brightness
in the pass 25 years. The observed amplitude in V band is only 0\fmm64,
a value typical for Weak line T Tauri stars.

\IBVSfig{6cm}{5214-f1.eps}{A finding chart of the comparison sequence in the field of V350 Cep}

\centerline{Table 1. Photometric data for UBVRI comparison sequence.}
\vskip 3mm
\begin{center}
\begin{tabular}{cccccccccccc}
\hline
Star & V & $\sigma_V$& I & $\sigma_I$ & $V-R$ & $\sigma_{V-R}$ & $B-V$ & $\sigma_{B-V}$ & $U-B$ & $\sigma_{U-B}$ & n \\
\hline
A & 13.946 & .031 & 13.065 & .045 & 0.646 & .051 & 0.770 & .033 & 0.225 & .062 & 7\\
B & 14.568 & .073 & 12.963 & .066 & 0.815 & .081 & 1.280 & .105 & 0.410 & .283 & 10\\
C & 14.947 & .054 & 13.935 & .052 & 0.569 & .078 & 0.924 & .058 & 0.380 & .084 & 10\\
D & 15.332 & .041 & 14.384 & .066 & 0.503 & .085 & 0.786 & .050 & 0.205 & .098 & 10\\
G & 16.057 & .033 & 14.628 & .053 & 0.775 & .091 & 1.202 & .060 & 0.104 & .152 & 6\\
H & 16.317 & .056 & 14.885 & .068 & 0.746 & .070 & 1.245 & .065 &       &      & 10\\
J & 16.250 & .067 & 14.079 & .050 & 1.004 & .058 & 1.530 & .084 &       &      & 9\\
K & 16.938 & .036 & 15.240 & .061 & 0.857 & .076 & 1.306 & .039 &       &      & 6\\
M & 16.623 & .074 & 14.257 & .068 & 1.193 & .091 & 2.015 & .097 &       &      & 10\\
\hline
\end{tabular}
\end{center}

\newpage

\centerline{Table 2. Photometric observations of V350 Cep in the period
December 1998 - September 2001}
\vskip 3mm
\begin{center}
\begin{tabular}{ccccccc}
\hline
J.D.(24...)  & V    & $U-B$ & $B-V$ & $V-R$ & $V-I$ & Tel. \\
\hline
51166.212 &  16.023 & $-$0.16 &  1.030 &  0.926 &  2.011 &  2m\\
51225.608 &  16.047 & $-$0.40 &  0.989 &  0.853 &  1.960 &  2m\\
51226.240 &  16.057 & $-$0.22 &  1.008 &  0.919 &  1.948 &  2m\\
51226.593 &  15.946 & $-$0.35 &  0.968 &  0.843 &  1.944 &  2m\\
51230.605 &  15.903 &   $-$   &  0.947 &  0.772 &  1.868 &  2m\\
51351.508 &  15.942 &   $-$   &    $-$   &    $-$   &    $-$   & 1.3m\\
51583.664 &  16.24~ &   $-$   &    $-$   &    $-$   &    $-$   &  Scm\\
51611.609 &  16.461 &   $-$   &    $-$   &    $-$   &  2.183 &  2m\\
51709.524 &  16.287 & $-$0.55 &  1.074 &  0.942 &  2.105 & 1.3m\\
51710.433 &  16.288 &   $-$   &    $-$   &    $-$   &  2.088 & 1.3m\\
51710.514 &  16.271 &   $-$   &  1.030 &    $-$   &  2.078 & 1.3m\\
51711.452 &  16.365 &   $-$   &    $-$   &    $-$   &  2.140 & 1.3m\\
51711.554 &  16.362 &   $-$   &    $-$   &    $-$   &  2.143 & 1.3m\\
51712.426 &  16.372 &   $-$   &    $-$   &    $-$   &  2.127 & 1.3m\\
51712.553 &  16.344 &   $-$   &  1.110 &    $-$   &  2.134 & 1.3m\\
51716.387 &  16.313 &   $-$   &    $-$   &    $-$   &  2.114 & 1.3m\\
51716.542 &  16.290 &   $-$   &  1.056 &  0.958 &  2.105 & 1.3m\\
51717.383 &  16.346 &   $-$   &    $-$   &    $-$   &  2.122 & 1.3m\\
51718.383 &  16.304 &   $-$   &  1.089 &  0.957 &  2.114 & 1.3m\\
51718.382 &  16.342 &   $-$   &  1.136 &    $-$   &  2.136 & 1.3m\\
51719.542 &  16.363 &   $-$   &    $-$   &  0.959 &  2.145 & 1.3m\\
51720.460 &  16.161 & $-$0.20 &  1.085 &  0.934 &  2.022 & 1.3m\\
51736.547 &  16.168 & $-$0.46 &  1.069 &  0.917 &  2.043 & 1.3m\\
51763.592 &  16.165 &   $-$   &    $-$   &  0.927 &  2.045 & 1.3m\\
51765.278 &  16.249 & $-$0.25 &  1.093 &  0.961 &  2.111 & 1.3m\\
51765.599 &  16.272 &   $-$   &    $-$   &    $-$   &    $-$   & 1.3m\\
51766.274 &  16.261 & $-$0.51 &  1.092 &  0.930 &  2.089 & 1.3m\\
51767.257 &  16.266 &   $-$   &    $-$   &    $-$   &  2.110 & 1.3m\\
51845.363 &  16.24~ &   $-$   &    $-$   &  0.87~ &  2.05~ &  Scm\\
51847.310 &  16.28~ &   $-$   &  1.08~ &  0.90~ &  2.15~ &  Scm\\
51847.349 &  16.34~ &   $-$   &    $-$   &  0.96~ &  2.16~ &  Scm\\
51903.322 &  16.11~ &   $-$   &  1.08~ &  0.86~ &  2.01~ &  Scm\\
52057.471 &  16.24~ &   $-$   &    $-$   &  0.90~ &  2.13~ &  Scm\\
52095.530 &  16.264 & $-$0.51 &  1.128 &  0.949 &  2.086 & 1.3m\\
52096.287 &  16.158 &   $-$   &    $-$   &    $-$   &  2.060 & 1.3m\\
52097.283 &  16.152 &   $-$   &    $-$   &    $-$   &  2.026 & 1.3m\\
52099.281 &  16.017 &   $-$   &    $-$   &    $-$   &  1.940 & 1.3m\\
52106.524 &  16.178 &   $-$   &    $-$   &    $-$   &  2.045 & 1.3m\\
52128.499 &  16.076 &   $-$   &    $-$   &    $-$   &  1.989 & 1.3m\\
52153.581 &  16.034 &   $-$   &    $-$   &    $-$   &  1.991 & 1.3m\\
52154.559 &  15.931 &   $-$   &  1.032 &    $-$   &  1.947 & 1.3m\\
52155.556 &  16.094 & $-$0.27 &  0.988 &    $-$   &  2.011 & 1.3m\\
52156.559 &  15.931 & $-$0.43 &  0.962 &    $-$   &  1.947 & 1.3m\\
52157.568 &  15.838 &   $-$   &    $-$   &    $-$   &  1.897 & 1.3m\\
\hline
\end{tabular}
\end{center}

\newpage

\IBVSfig{10cm}{5214-f2.eps}{B/pg- and V-band light curves of V350 Cep}

\references

Landolt, A.U., 1992, {\it AJ}, {\bf 104}, 340 

Magakian, T.Y., Movsesian, T.A., Hovhannesian, E.R., 1999, {\it Astrophisics},
{\bf 42}, 121 \BIBCODE{1999Ap.....42..121M}
% Original: Magakian, T.Y., Movsesian, T.A., Hovhannesian, E.R., 1999, {\it Astrofizika},
% Corrected: Thu Aug 14 14:03:55 MET DST 2003

Pogosyants, A.Yu., 1991, {\it IBVS}, No. 3624 

Semkov, E.H., 1993, {\it IBVS}, No. 3825 

Semkov, E.H., 1996, {\it IBVS}, No. 4339 

Semkov, E.H., Mutafov, A.S., Munari, U., Rejkuba, M., 1999,
{\it AN}, {\bf 320}, 57 

\endreferences

\end{document}
