COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2053

                                 Konkoly Observatory
                                 Budapest
                                 1981 December 9

                                 HU ISSN 0374-0676




        SAO 072799, A NEW BRIGHT ECLIPSING BINARY




The variability of  SAO 072799 (BD +37d4713) was detected
photographically by one of us. The star was suspected to be an
eclipsing binary. This could be confirmed photoelectrically by
the other. Despite the fact of a still incomplete light curve
we present our results  now, to make possible that other 
observers join the observation of this interesting star.
Photoelectric observations were made by a digital photometer
equipped with an EMI 9781B tube in B, using the filters Schott
BG 12+GG 13  (2mm), with a 25 cm Schmidt-Cassegrain telescope.
SAO 072816 (F0,m_v =7.6m) served as comparison star, the constancy              
of which was checked with  SAO 072806 (M0,m_v =7.1m). The latter
was found to be variable during the course of the observations
(A ~0.1m).
The observed minima of SAO 072799 are given in Tab.I. It was
possible to find retrospectively some more on the photographic
films. The times of these minima are also included. The

                  Table I

The minima with asterisks were extrapolated from parts of the
decrease or increase
-------------------------------------------------------------
Epoch  Min.JD2444... O-C    p or B
-------------------------------------------------------------
-15.5*   143.4913   +0.163    p
 0*      257.2789   -0.0037   p
 35.5    518.4573   +0.1863   p
 51      632.2236   +0.0090   p
 83      867.4795   -0.0013   B
 84.5*   878.6625   +0.1541   B
 88.5*   908.0849   +0.1684   B
 89      911.5875   -0.0040   B
 89.5    915.4233   +0.1559   B
-------------------------------------------------------------

star shows primary and secondary minima of almost equal depth.
From the times of the primary minima the following elements
were calculated:

      Min.= JD 2444 257.2826 + 7.351785d
                       +- 43      +- 65

                    [FIGURE 1]

The O-C against these elements are also given in Tab.I, in the
case of the secondary minima the O-C against the phase 0.50 is
calculated. With these elements the lightcurve in Fig.1 was
obtained from the observations in B. The secondary minimum lies
clearly excentric at the phase 0.52. Also the shape is different
from that of the primary. The latter shows a "D" of 10.0, and a
"d" of 0.6 hours, the values for the secondary are: "D" 13.6,
"d" = 1.6 hours. The amplitudes in B are A_1 = 0.74m, A_2 = 0.64m.
Whereas the primary minimum is symmetric, the secondary shows a
steeper increase immediately after the constant phase. Also the
maximum light seems to be distorted. Especially around the phase
0.2 after both minima a small decrease in brightness (~0.08m) is
obvious. This has been found also repeated in the photographic
light curve and was originally described as secondary minimum in
IBVS 1885. All other peculiarities described here were also found
by the photographic observations. After completion of the light
curve all data will be published in "BAV-Rundbrief".





             M. FERNANDES

             P. FRANK

             BAV, Munsterdamm 90
             1000 Berlin 41, Germany





Reference:
Frank, P., 1980 IBVS No. 1885