COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2375

                                    Konkoly Observatory
                                    Budapest
                                    27 July 1983

                                    HU ISSN 0374-0676



      NEW PHOTOELECTRIC TIMES OF MINIMA OF VW CEPHEI




   VW Cep (BD +75d752) is a well known eclipsing binary of
W UMa-type, which has both variable period and variable light
curve. Due to the peculiarities of VW Cep, it has been the subject 
of many investigators. So, many photoelectric light curves
of the system have been obtained and a great deal of theoretical 
work has been done for a better understanding of this peculiar 
system.
   During a program of photoelectric observations of eclipsing
binary stars, the system was observed in two colours (B and V)
on September 5-11, 1980.



                    Table I
-----------------------------------------------------
     HJD       sigma    (O-C)_1   (O-C)_2 Filter Min.
-----------------------------------------------------
2440000+
   4488.4702  +-0.0001  -0.0002   -0.1072   B,V   II
   4489.3063  +-0.0002  +0.0009   -0.1060   B,V   II
   4489.4439  +-0.0001  -0.0006   -0.1076   B,V    I
   4490.4189  +-0.0001  +0.0003   -0.1067   B,V   II
   4490.5577  +-0.0001  -0.0001   -0.1071   B,V    I
   4491.3926  +-0.0001  -0.0001   -0.1071   B,V    I
   4492.3681  +-0.0002  +0.0013   -0.1057   B,V   II
   4492.5060  +-0.0001   0.0000   -0.1070   B,V    I
   4493.3409  +-0.0001   0.0000   -0.1070   B,V    I
   4493.4803  +-0.0001  +0.0002   -0.1068   B,V   II
   4494.3158  +-0.0002  +0.0008   -0.1063   B,V   II
   4494.4537  +-0.0001  -0.0005   -0.1075   B,V    I
-----------------------------------------------------

   The observations were made with a 48-inch Cassegrain reflector 
(Contopoulos and Banos, 1976) and a two beam multi-mode
photometer (Goudis and Meaburn, 1973). The two intermediate passband 
filters used were selected to be in close accordance with
the standard U,B,V colour system. As comparison star we used
BD +74d889, as check star BD +75d726.
   All the times of minima and the mean errors a were calculated 
by the method of Kwee and Van Woerden.
   The successive columns of Table I contain the heliocentric
time of minimum, the mean error sigma, the differences O-C, the
filter used and the type of minimum.
   The (O-C)_1 values were computed using the ephemeris given
by Hopp et al.(1979)

        Min I = JD Hel 2443410.4180 + 0.27831481d E

while the (O-C)_2 values were calculated according to van't
Veer's (1973) ephemeris

        Min I = JD Hel 2433898.4410 + 0.27831793d E





               P.G. NIARCHOS
               Department of Astronomy
               University of Athens
               Panepistimiopolis
               Athens 621
               GREECE





References:
Contopoulos, G. and Banos, C.: 1976, Sky and Telescope, 51, 152. [BIBCODE 1976S&T....51..154C ]
Goudis, C. and Meaburn, J.: 1973, Astrophys. Space Sci., 20, 149. [BIBCODE 1973Ap&SS..20..149G ]
Hopp, U., Witzigmann, S. and Kiehl, M.: 1979, I.B.V.S. No. 1599.
van't Veer, F.: 1973, Astron. Astrophys. 26, 357. [BIBCODE 1973A&A....26..357V ]