COMMISSION 27 OF THE I. A. U.
                   INFORMATION BULLETIN ON VARIABLE STARS
                                Number 2464

                                                          Konkoly Observatory
                                                          Budapest
                                                          24 January 1984
                                                          HU ISSN 0374-0676



                 REVISED PHOTOMETRIC RESULTS OF SAO 072799



 A request for a confirmation of the variability of the star SAO 072799
(Frank, 1980) led us to observe this star photoelectrically in August-
September 1981, as well as in September 1982. The observations made during
these seasons had been reduced according to the preliminary ephemeris (Frank,
1981)

      Min I = JD Hel 2444632.2326 + 4.215095d x E         (1)

and the results have been given in I.B.V.S. No. 2435. From the shape of the
light curves given in Figures 1 and 2 of the above mentioned work, it was
difficult to define the type and the period of the variability of SAO 072799.
  But more recent photometric work (Fernandes and Frank, 1981, Kroll, 1983)
led us to reanalyse our observations according to the ephemeris (Fernandes
and Frank, 1981)
      Min I = JD Hel 2444257.2826 + 7.351785d x E        (2)
Two times of the secondary minimum, given in Table I, have been derived, one
by essentially visual inspection and the other by extrapolation of the
ascending branch of the respective minimum.

                         Table I
   HJD          (O-C)1   (O-C)2     E     Filter      Min.
                                                        
2444849.2483   +0.1470   +0.1643   80.5    B,V        II*
2445231.5414   +0.1473   +0.1782   132.5   B,V        II

 The (O-C)_1 values have been computed by using the ephemeris given by
Equation (2), while the (O-C)_2 values have been found according to the
ephemeris (Kroll, 1983).

      Min I = JD Hel 2444257.2865 + 7.351522d x E

 The observed light curves are given in Figures 1 and 2. From an inspection
of Figure 2 it is obvious that a secondary minimum occurs at the phase 0.52
(see also Fernandes and Frank, 1981). Here the descending and a small part


* By extrapolation



                             [FIGURE 1]

          Figure 1   B and V light curves of SAO 072799




                             [FIGURE 2]

          Figure 2   B and V light curves of SAO 072799





of the ascending one can easily be seen. In Figure 1 the ascending branch of
the secondary minimum is clearly shown. By extrapolating this part of the
light curve we expect the minimum time roughly at the phase 0.52. The maximum
light in both Figures seems to be distorted.
  From our observations and those made by others (Frank, 1980, Fernandes
and Frank, 1981; Kroll, 1983) there is no doubt that the star SAO 072799 is
an eclipsing variable with primary and secondary minima of almost equal depth.
For a better understanding of this newly discovered eclipsing variable more
observations are needed.





             P.G. NIARCHOS

             Department of Astronomy
             University of Athens
             Panepistimiopolis, Athens 621
             Greece





References:
Fernandes, M. and Frank, P.: 1981, I.B.V.S. No. 2053
Frank, P.: 1980, I.B.V.S. No. 1885
Frank, P.: 1981 (private communication)
Kroll, P.: 1983, Mitt.Verand. Sterne Sonneberg, 9, p. 187 [BIBCODE 1983MitVS...9..187K ]
Niarchos, P.: 1983, I.B.V.S. No. 2435