COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                      Number 1870

                                  Konkoly Observatory
                                  Budapest
                                  1980 November 17

                                  HU ISSN 0374-0676




            HD 200925, A PULSATING VARIABLE




    The star HD 200925 (BD +50d3259) was observed by Bedolla
and Pena (1979) on four nights during 25th to 28th September
1978 in V filter. They reported this star as a variable with a
tentative period of 0.238d, and no definite type of its variability 
is given.
    To determine its accurate period and establishing its type
of variability, the star was observed by us photoelectrically
on the 38 cm reflector of the Uttar Pradesh State Observatory
on a total of seven nights during October-December 1979, using
a cooled (-20^o C) 1P21 photomultiplier tube, the conventional
U, B and V filters of the Johnson and Morgan system, and standard
d.c. techniques. The data were reduced to the standard system.
HD +50d3256 was used as a comparison star. The average standard
deviations of the comparison star are 0.015m, 0.010m and 0.010m
in U, B and V filters, respectively.
    On the basis of the maximum of the individual light curves
observed by us and those reported by Bedolla and Pena, we determined 
a period of 0.267396d. In our U, B and V light curves magnitude 
variations of 0.54m, 0.45m and 0.32m, respectively have
been noticed. The variation in B-V colour during a pulsation
cycle is 0.14m. The V light curve of our individual observations
and normal B-V colour curve covering the whole cycle, are given
in Figure 1.
    From the shapes of the light and colour curves, the star
appears to be a short period cepheid variable. The mean values
of B-V and U-B colours have been determined to be 0m30 and 0m07
respectively which indicate that it belongs to spectral type

                       [FIGURE 1]

F2 III. Using the period and B-V colour (assuming there is no
reddening), determined by us, in the P-L-C relation (Gupta,
1977), the absolute magnitude (M_v) is derived to be 0.37m +- 0.16m.
Plotting these values of M_v and B-V in the colour magnitude
diagram the star lies within the cepheid instability strip,
which further supports that the star HD 200925 is a cepheid
variable.
     A detailed analysis of the UBV light curves and further
observations are in progress.
     The authors are thankful to Dr. S.D. Sinvhal for fruitful
discussions.





                     S.K. GUPTA and T.D. PADALIA
                    Uttar Pradesh State Observatory,
                    Manora Peak, Naini Tal - 263129,
                            India

References:

Bedolla, S.F.G. and Pena, J.H., 1979, I.B.V.S. No. 1615
Gupta, S.K., 1977, Astrophys. Space Sci. 59, 85 [BIBCODE 1978Ap&SS..59...85G ]