COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                      Number 2676


                                   Konkoly Observatory
                                   Budapest
                                   1 March 1985

                                   HU ISSN 0374 - 0676


   IMPROVED PERIOD FOR THE CATACLYSMIC VARIABLE V795 Her=PG 1711+336:

              IS IT AN OUTSTANDING OBJECT?


  Periodic light variations of the star PG 1711+336 were noticed by Mironov et
al. (1983a, b). An identification chart, photoelectric magnitudes of 13 nearby
stars and the position of the object in the (B-V, U-B) diagram were given in
the first paper (1983a). The colour temperature of PG 1711+336=V795 Her was
shown to be 20000dK. In the second paper (1983b) the position of the object
in the (B-V, W-B) colour diagram was shown.
  The photometry of V795 Her during the 1968-85 years has revealed long-term
variability from 12.5m to 13.2m in B and short-periodic light variations with
the amplitude 0.3m and the period P=0.11583d.
  Monitoring of the variable was continued in 1984. Now we obtained 38 
individual points in U, 75 in W, 213 in B, 116 in-V and 59 in R. (Julian 
Dates 2445442- 2445959). Tables of observations will be given elsewhere.
  An analysis of all observational points, obtained for V795 Her from 1983,
allows us to improve the period of the optical light variations, which turns
out to be two minutes shorter than given previously. The improved ephemeris
is as follows:

            JD Min.hel.=2445527.295+0.114488d*E

  The light curve in B plotted with this ephemeris is shown in Figure 1.

                                   Figure 1: The B light curve of
                                   V795 Her. Notation: (.) - observations
                                   obtained with the 48 cm
                                   reflector at Tian-Shan
         [FIGURE 1]
                                   High-Altitude (3000m) Observatory
                                   of SSAI in Alma-Ata; (x) - observations
                                   obtained with the 60 cm
                                   Zeiss reflector at the SSAI
                                   Crimean laboratory (the altitude
                                   is 600 m).

The minimum appears to be highly asymmetric ; egress is steeper than ingress.
The out-of-eclipse magnitude, as well as a shape of the light curve, slightly
change from cycle to cycle due to intrinsic variability. This leads to a significant
scatter of the individual points in the light curve. Moreover, there are slight
variations of (B-V) colour with the phase; near the maximum light, B-V= -0.08m,
and in a half-cycle, B-V=-0.02m,
  If the period determined is really the case, and not twice longer, then the
variable falls into the gap in a histogram which describes distribution of
cataclysmic variables vs. the period. If so, V795 Her can be a unique object.
We recommend that more attention be paid to this star by observers, especially
by spectroscopists. A radial-velocity curve for the star is highly needed in
order to prove the value of the orbital period. A detailed investigation of
physical parameters of V795 Her would help to interprete the nature of an
observational "gap" in the distribution of cataclysmic variables.





                      A.V. BAIDAK
                      N.A. LIPUNOVA
                      S. Yu. SHUGAROV
                      Sternberg State Astronomical
                      Institute(SSAI), 13, Universitetskij
                      Prospect, Moscow, 119899, USSR

                      V.G. MOSHKALEV
                      I.M. VOLKOV
                      Tian-Shan High-Altitude Observatory
                      of the Sternberg Astronomical Institute.



References;

Mironov, A.V., Moshkalev, V.G., Shugarov, S.Yu.,1983a : Astr.Tsirk. No. 1279,
         6 (in Russian). [BIBCODE 1983ATsir1279....6M ]
Mironov, A.V., Moshkalev, V.G., Shugarov, S.Yu.,1983b : I.B.V.S., No. 2438.