COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                       Number 1100

                                 Konkoly Observatory
                                 Budapest
                                 1976 February 11




    PHOTOELECTRIC MINIMA AND LIGHT CURVES OF BS DRACONIS


The variability of the system was discovered by Strohmeier
(1962). The light elements were obtained by him as follow:

           Hel.Min.J.D. 2426 444.475+1.682000d  E.

The first spectroscopic observations were made and analyzed
by Fitzgerald (1964). The system shows double line spectra. Both
of the components have the same spectral type and line intensities. 
Fitzgerald also showed that the period of the system should
be twice that of given by Strohmeier.
Photoelectric observations of BS Dra in B,V, colours were
made with the 48 cm Cassegrain telescope at the Ege University
Observatory on 21 nights between May 1972 and May 1973. The 
photometer was furnished with a 1P21 photomultiplier tube and standard 
Johnson B,V filters. In the observations BD +73d881 was used
as comparison star. Four primary and three secondary minima were
obtained and are given in the following Table.


              Times of Minima
-------------------------------------------------
Hel.Min.         Min.     O-C_I    O-C_II  Filter
-------------------------------------------------
2441461.4252      I      +.0542   +.0010   B,V
    471.5166      I      +.0536   +.0004   B
       .5163      I      +.0533   +.0001   V
    488.3335      I      +.0505   -.0028   B
       .3345      I      +.0515   -.0018   V
    493.3817      II     +.0527   -.0006   B
       .3838      II     +.0548   +.0015   V
    594.304       II     +.055    +.001    B,V
    826.4196      II     +.0546   -.0002   B,V
  42302.4277      I      +.0567   -.0001   B
       .4280      I      +.0570   +.0002   V
-------------------------------------------------


C_I and C_II values were obtained with the elements of Strohmeier 
and the new elements obtained by us:
            
      Hel.Min.J.D.2441461.4242+3.3640145d E.
                           +-2      +-21

The light and colour curves are shown in the Figure.  The
phases of the observations were calculated with the above new
light elements.   All the observations were corrected for differential 
extinction. The star varies about 0.720m at the primary
and 0.700m at the secondary minimum in both colour. A detailed
analysis of this system will be published elsewhere.

                       [FIGURE 1]

   This study is a part of research project No. 76 supported by
the Scientific and Technical Research Council of Turkey.



Ege University Observatory                C. IBANOGLU
P.K. 21 Bornova-Izmir, Turkey.            S. BOZKURT
                                          N. GUDUR
                                          O. GULMEN




References:

Fitzgerald, P. 1964, Publ. David Dunlap Obs. 2, 417 [BIBCODE 1964PDDO....2..417F ]
Strohmeier, W., 1962, I.B.V.S. No. 9