1982-1988 PHOTOMETRY OF THE TOTALLY ECLIPSING CHROMOSPHERICALLY ACTIVE BINARY V792 HERCULIS EQUALS HD-155638

We present 1985-1988 UBV and VRI photometry obtained at three differen t observatories and analyze it along with previously published 1982-19 84 UBV photometry. New times of midprimary eclipse along with previous ly published times yield the improved orbital ephemeris T(pri.min.)=JD 2446674.185(+/-0.007)+27.(d)53707(+/-0.d00026)n. Periodogram analysis of previously published radial velocities, for both the K giant and t he F subgiant, yields orbital ephemeris constants consistent with the one above, but of lesser precision. Fitting the seven years of photome try with a cos(2 theta) curve, after removing the eclipse points, yiel ds 0.(m)021+/-0.(m)006 for the full amplitude of the ellipticity effec t in V. Residuals from that cos(2 theta) fit give light curves which r eveal continuing starspot variability, which had been seen in the 1982 -1984 photometry. These residuals, in ten data groups, are analyzed wi th a two-spot light-curve fitting procedure. Six long-lived spots are identified, the largest producing a light loss of 0.(m)166 in V. Lifet imes were >2.85, 0.81, 1.88, 1.84, >0.58, and >0.45 yr. Rotation perio ds for these six spots have a mean of 27.(d)36+/-0.(d)06, thus confirm ing synchronous rotation, and a range which indicates a differential r otation coefficient of k=0.031. With respect to the value of 0.65 belo w which strong dynamo action is expected in a convective star, the Ros sby number for the K giant, believed to be the spotted star, is 0.17, well below the threshold and so large starspots are expected. (C) 1996 American Astronomical Society.