COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1705

                                Konkoly Observatory
                                Budapest
                                1979 November 15


             VARIABILITY OF SS433


Photoelectric photometry of SS433 was obtained on three consecutive
photometric nights in June 1979 using the 150 cm telescope of The Pennsylvania
State University. A broadband interference filter with a FWHM of 700 A and
centered at 5500 A was used to isolate a relatively line free region near
the V band. The instrumental magnitudes were adjusted in zeropoint to the
nearby comparison star with V=13.7, B-V=0.7 (IAUC 3379). Study of
published spectra indicated that, with the expected velocity shifts, the
strong emission lines in SS433 could contribute only a few percent of the
signal. On June 26.140-26.335 and 27.115-27.322 UT the magnitude of SS433
was constant at 15.11 within +-0.15 mag on timescales down to minutes.
Observations over a shorter period on June 25 gave a result 0.3 mag brighter.


S. HOWELL
R.J. PANEK
Department of Astronomy
The Pennsylvania State University
University Park, PA 16802