COMMISSION 27 OF THE I.A.U.
                INFORMATION BULLETIN ON VARIABLE STARS
                            Number 3277

                                                         Konkoly Observatory
                                                         Budapest
                                                         30 December 1988

                                                         HU ISSN 0374 - 0676


            PHOTOELECTRIC OBSERVATIONS OF ST AQUARII

The eclipsing binary ST Aquarii (BD -7d5753, HD 211965, SAO 146035)
discovered by Miss Leavitt at Harvard (Pickering, 1908). She classified the
system to be an Algol type. Zacharov (1928) estimated the period to be
0.390455d. Later on Mergentaler (1928) discovered that the period should be
much longer than that estimated by Zacharov. Zacharov (1930) reclassified
the system to be Beta-Lyrae type, and he found the period about twice the 
original value, or 0.7810161d. The system consists of a bright A7 component
accompanied with a faint G8IV component (Roman, 1956).
   The eclipsing binary ST Aqr was observed photoelectrically at Kottamia
observatory (Egypt) on 5 nights during October to December 1978. The
cassegrain focus of the 74-inch reflector was equipped with a cooled two-
channel photometer. The detector was an EMI 9862B/350 photomultiplier tube,
powered by an Isotopes Development Ltd. type 1388 D.C. amplifier and then
fed to a Honeywell chart recorder. Two wide - band filters (B, V) have
been used in this work. The blue filter was a BG12 1mm + GG385 2mm, and
the yellow filter was a BG18 1mm + GG495 2mm Schott Glass B filter. The
effective wavelength for B and V filters were 4258 A and 5385 A, respectively,
and the bandwidth for the filters was 982 A for B and 981 A for V.
   For comparison and check, the stars BD -7d5751 and BD -7d5755 were used,
respectively. A total of 386 and 370 observation points were obtained in
B and V filters. The phases of the observations have been computed from the
light elements given by Gleim (1973):

  Min I (Hel.) = 2441 236.316 + 0.78099525d E

the times of minima and O-C values derived from the light curves.


                         [FIGURE 1]
                         [FIGURE 2]


                         Table I

               Times of minima and O-C values

Minimum   Observed (Hel.J.D.)   Calculated (Hel.J.D.)     O-C

 I        2443801.9104          2443801.8854             0.0250
 II       2443835.8877          2443835.8587             0.0290



             HAMID M. AL-NAIMIY and HASAN A. FLEYEH

                Astronomical Research Unit
                Scientific Research Council
                  Jadiriah Bagdad, Iraq.



References:

Gleim, J.K., 1973, Astron. J. 78, 662 [BIBCODE 1973AJ.....78..622G ]
Mergentaler, J., 1928, Acta Astron. 1, 35, 154
Pickering, E.C., 1908, Harvard Coll. Obs. Circ., No. 142, 2 [BIBCODE 1908HarCi.142....1L ]
Roman, N.G., 1956, Astrophys. J. 123, 247 [BIBCODE 1956ApJ...123..246R ]
Zacharov, G., 1928, Beobach. Zirk. Astron. Nachr. 10, 22
Zacharov. G., 1930, Beobach. Zirk. Astron. Nachr. 12, 90