COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                      Number 2792

                                        Konkoly Observatory
                                        Budapest
                                        16 September 1985

                                        HU ISSN 0374 - 0676


         NEW PHOTOELECTRIC OBSERVATIONS OF SZ Her



   Photoelectric observations of the binary star SZ Her,
BD+33deg2930, were made on 7 nights (May and June 1985) at the
Stephen F. Austin State University Observatory. The telescope
utilized was a computer-controlled 46 cm Ritchey-Chretien which
automatically moves between objects at the end of each filter
cycle (Michaels, 1981, and Markworth and Michaels, 1982). The
photometer was a Thorn EMI Gencom, Inc. "Starlight-1" photon
counting system and was interfaced to a Commodore 64 computer for
data acquisition. The "Starlight-1" was equipped with an
uncooled EMI 9798A S-20 response PMT. The 615 observations were
made in the natural V and R system of the telescope/photometer
combination with the R observations presented in Figure 1.
   From these observations 6 primary and 2 secondary times of
minima were obtained. Since the eclipses were fairly symmetric
during this epoch, the bisection of chords method was used to
determine mideclipse with the results presented in Table I
(Henden, 1982).
   The observed times of minima were late by an average of 52
minutes from the predicted values. The predicted minima were
computed using the ephemeris given below (Wood et al, 1980).

       Hel JDmin = 2434987.3852 + 0.81809387d
           


              Table I



 Filter  JD(2440000+)  Type
             min

   V     6210.8518     Pri
          +/-.0004
   R     6210.8518     Pri
          +/-.0006
   V     6224.7558     Pri
          +/-.0004
   R     6224.7584     Pri
          +/-.0005
   V     6231.7199     Sec
          +/-.0052
   R     6231.7154     Sec
          +/-.0017
   V     6237.8473     Pri
          +/-.0008
   R     6237.8473     Pri
          +/-.0005


                              [FIGURE 1]

 Figure 1  The individual differential magnitudes of SZ Her in the
 sense (variable-comparison)





   An extensive literature search is now under way to locate
the over 300 times of minima published for SZ Her. A complete
period and light curve analysis will be published elsewhere.





                   E. J. MICHAELS
                   Stephen F. Austin State University
                   Department of Physics and Astronomy
                   Box 13044
                   Nacogdoches, TX 75962





References:

Markworth, N. L. and Michaels, E. J., 1982, Publ. Astr. Soc.
   Pacific 94, 350. [BIBCODE 1982PASP...94..350M ]

Michaels, E. J., 1981, Master's Thesis, Stephen F. Austin State
   University.

Wood, F. B., Oliver, J. P., Florkowski, D. R., and Koch, R. H.,
   1980, in "A Finding List for Observers of Interacting Binary
   Stars" (Philadelphia: University of Pennsylvania Press).

Henden, A. A. and Kaitchuck, R. H. in "Astronomical Photometry",
   (New York: Van Nostrand Reinhold Company, Inc.). [BIBCODE 1990apth.book.....H ]