COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2608

                                    Konkoly Observatory
                                    Budapest
                                    18 October 1984

                                    HU ISSN 0374 - 0676




       PERIOD AND LIGHT CURVE OF THE RRc STAR VZ VIRGINIS


   The variability of this star was detected in 1927 by Belyavsky, but no
further investigations have followed.
   In a search for blue objects in high galactic latitudes Bond and Tifft
(1974) found the spectral type of VZ Vir to be B8 hb (horizontal branch).
   Since February 1983 I have observed VZ Vir photoelectrically in B and V
with the 60 cm reflector II of Sonneberg Observatory. The conditions for
these observations were never very good because of the low declination of
this object. The mean error in one night was about 0.05 to 0.1 mag.

                           [FIGURE 1]

  In 1983 a preliminary period of VZ Vir was derived (Luthardt, 1983). By
using the observations of 1984 the elements could be improved. A calibration
in magnitude of the comparison star has not been made yet.

  Elements of VZ Vir:     Max. = J.D.hel. 244 5388.651+ 0.3396113d X E
  Amplitude:               A_V = 0.55 mag
  Range of B-V:     Delta(B-V) = 0.20 mag +- 0.05 mag

These elements and the form of the light curve - nearly symmetrical, a small
hump on the ascending branch - let us expect an RRc star. For constructing
the light curve given in the Figure moving averages are used.




                           R. LUTHARDT

                       Sonneberg Observatory of

                    Central Institute for Astrophysics
                    of Academy of Sciences of the GDR
                         6400 Sonneberg, GDR





References:

Bond, H.E., and Tifft, W.G., 1974: Publ. Astron. Soc. Pacific, 86, 981. [BIBCODE 1974PASP...86..981B ]
Luthardt, R., 1983: Mitt. Veranderl. Sterne, 10, Heft 2, p. 29. [BIBCODE 1983MitVS..10...29L ]