Photoelectric and Visual Observations of X Persei

Volume 21 number 1 (1992)

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John R. Percy

Erindale Campus, University of Toronto, Mississauga, Ontario, Canada L5L 1C6

Abstract

X Persei, the optical counterpart to the X-ray source 4U0352+30, consists of a neutron star secondary accreting from an O9.5IIIe star. Detailed photoelectric (UBV) observations of X Persei have been obtained from (i) the AAVSO Photoelectric Photometry Program and (ii) the Automatic Photometric Telescope (APT) Service in Arizona. These observations (and a light curve based on 30-day means of AAVSO visual observations since 1962) serve to define the complex variability of the star in the last three decades, including an interval since 1989 when the star has been non-variable at the 0.01 magnitude level.