COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                       Number 3377

                                         Konkoly Observatory
                                         Budapest
                                         3 October 1989

                                         HU ISSN 0374 - 0676


         1989 BV PHOTOELECTRIC OBSERVATIONS OF BV Dra


BV Dra was detected as an eclipsing binary by Batten and Hardie (1965).
Photoelectric observations by Wood (1970), Rucinski (1976), Yamasaki (1979),
Rovithis and Rovithis-Livaniou (1982) indicate that the star is a normal W UMa
system. BV Dra, which forms a visual binary (ADS 9535) with BW Dra, was
observed from 20 May through 29 May 1989 with the 1.2m Kryonerion telescope and
a single channel photon counting photometer described by Dapergolas and
Korakitis (1987). The photometer employs a high gain 9789QB phototube and
conventional BV filters. Its output is fed directly to a microcomputer
enabling rapid data access.

The data reduction method is the standard one. The comparison star is the BD
+62d1395 and the accuracy of observations is +-0.02 mag.

Table I lists the dates of observations and phases covered whereas Figures 1
and 2 summarize the results for B and V colours.

Table I

Date               Phase

20 May 1989      .11   .38
                 .55   .73
21 May 1989      .11   .72
25 May 1989      .33   .11
29 May 1989      .03   .26

In Table II the times of minima and the O-C values are listed for the B and V
bands respectively. Times of minima are calculated using the method described
by Kwee and van Woerden (1956) whereas the O-C values were determined from the
linear ephemeris T=J.D.2442878.372 + 0.3500663d E (Geyer et al., 1982).


                             [FIGURE 1]
                             [FIGURE 2]


                         Table II
    V COLOUR                                   B COLOUR

Type of   Heliocentric    (O-C)      Heliocentric     (O-C)
minima    Jul. Day        phase      Jul. Day         phase

Secondary   2447668.5063   0.506     2447668.5069       0.507
                +-0.0002  +-.001         +-0.0005      +-.001
Secondary   2447672.3573   0.507     2447672.3549       0.500
                +-0.0002  +-.001         +-0.0005      +-.002
Primary     2447672.5316   0.005     2447672.5337       0.010
                +-0.0006  +-.002         +-0.0005      +-.002
Primary     2447676.3799   0.998
                +-0.0006  +-.002

From the Figures 1 and 2 it can be seen that the light curve is not fully
symmetric, and the differences between primary and secondary minima are ~0.05
mag in B and ~0.02 mag in V.


A. DAPERGOLAS and E. KONTIZAS    M. KONTIZAS
National Observatory of Athens   University of Athens
Astronomical Institute           Laboratory of Astrophysics
P.O. Box 20048                   Panepistimiopolis
GR Athens 118-10                 GR Athens 151-71
Greece                           Greece

References:

Batten, A.H. and Hardie, R.H.: 1965, Astron.J., 70, 666. [BIBCODE 1965AJ.....70..666B ]
Dapergolas, A. and Korakitis, R.: 1987, Publ. Nat. Obs. of Athens, Ser II,
   No. 28.
Geyer, E.H., Hoffmann, M. and Karimie, M.T.: 1982, Astron. Astrophys.
   Suppl. Ser., 48, 85. [BIBCODE 1982A&AS...48...85G ]
Kwee, K.K. and van Woerden, H.: 1956, Bull. Astr. Inst. Netherlands, 12, 327. [BIBCODE 1956BAN....12..327K ]
Rucinski, S.M.: 1976, IAU Symp., No. 73, 349, eds. P. Eggleton and J. Whelan. [BIBCODE 1976IAUS...73..349R ]
Rovithis, P. and Rovithis-Livaniou, H.: 1982, Astrophys. Space Sci., 82, 229. [BIBCODE 1982Ap&SS..82..229R ]
Wood, D.B.: 1970. Bull. American Astron. Soc., 2, 357. [BIBCODE 1970BAAS....2Q.357W ]
Yamasaki, A.: 1979, Astrophys. Space Sci., 60, 173. [BIBCODE 1979Ap&SS..60..173Y ]