The Period of AG Pegasi: Having Another Go.

The period of the symbiotic binary star AG Peg has been determined from photoelectric data, including previously unpublished data from the 1970s, as well as new observations. Altogether, 89 V magnitudes are available for discussion. These are corrected for a discrepancy in the magnitude of a comparison star used by various workers, and for a secular decline in the system's visual brightness of 0.021 mag/yr. Five different methods of period determination yield consistent results with a mean of 816.5 plus or minus 0.9 days, leading to an ephemeris for times of maximum visual light of (JD)max = 2442710.1 + 816.5E. A light curve based on normal points formed from the 89 individual observations is shown.