COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                     Number 3132




                                     Konkoly Observatory
                                     Budapest
                                     19 January 1988

                                     HU ISSN 0374-0676


      A RECENT LIGHT CURVE FOR THE BRIGHT W UMa TYPE ECLIPSING
                            BINARY GR Vir
          

  GR Vir = HD 129903 has been found to be an eclipsing binary of the W UMa
type. First indications of its variability were given by Strohmeier et al,
(1965), who stated that the photographic amplitude was 0.4 magnitudes. A
partial light curve was published by Harris (1979) who gave a provisional
period of 0.3472 days on the basis of 3 nights of observation, Hoffmann (1983)
published a radically different period (0.419757 days) which was adopted for
the most recent edition of the General Catalog of Variable Stars. No recent
spectral classifications beyond that of G0 given in the SAO Catalog could
be located.

  GR Vir has been observed in BV colors at intervals between JD 2446121 -
6952 with the 0.6 m telescope of the Corralitos Observatory and its single
channel photon-counting photometer and uncooled EMI 9924A photomultiplier
tube, and on JD 2446866 - 7 with the Kitt Peak Observatory #2 0.9-m. telescope 
with its automated filter photometer and cooled 1P21 tube. Observations
of standard stars revealed no systematic color differences to > 0.002 magnitudes
between the Corralitos and Kitt Peak systems. The primary comparison
star chosen was HD 129870 (V = 8.99 ; B-V = +.62; G0) with HD 129976 (V = 9.43;
B-V = +.90; G) used as a check of its non-variability. The standard errors of
the mean magnitude of (HD 129976 - HD 129870) were 0.012 in V magnitude and
0.016 in B-V.

  A period of 0.346975 days was found for GR Vir on the basis of 916 
observations over a total of nearly 2400 cycles. This period is in good 
agreement with that originally suggested by Harris. Plotting the same data with the
Hoffmann period showed that his period is in error and does not represent the
observations very well. The V magnitude of the symmetrical maxima is approximately 
7.81 and the eclipse depths of primary and secondary minima, 0.36 and
0.31 V magnitudes respectively. There is a slight reddening during primary
eclipse of about 0.03 magnitudes in B-V, leading to the conclusion that the
secondary star is slightly later in spectral type and less luminous.


                              [FIGURE 1]

 Figure 1: V magnitude light curve and B-V color changes for GR Vir. These
           are shown as differences between the comparison star HD 129870
           and the variable GR Vir.


   The eclipses may be total. Graphic depiction of the light curve and color
changes appear in Figure 1, with phase calculated by the following ephemeris:

         Prim. Min. = Hel. JD 2446560.85006 + 0.346975 d E

   An analysis of the light curve will be published later. Kind thanks are
tendered to L. Szabados for pointing out the variable designation and a helpful
reference.


                          E.M. HALBEDEL

                          Corralitos Observatory
                          P.O. Box 16314
                          Las Cruces, NM 88004
                          U. S. A.



References:
Harris, A.W. 1979, Inf. Bull. on Var. Stars, No. 1691.
Hoffmann, M. 1983, Inf. Bull. on Var. Stars, No. 2344.
Strohmeier, W., Knigge, R., and Ott, H. 1965, Inf. Bull on Var. Stars, No. 115.