The radio, optical, X-ray, gamma-ray star LSI +61 deg 303

Abstract

The highly variable radio source, GT 0236+610, previously reported as a possible counterpart for the gamma-ray source CG 135+1, is identified with a B0-1 star (LSI +61 deg 303) having unusually broad H-alpha and H-beta emission lines. High-time-resolution radio observations imply that the size of the radio emitting region is no more than 3 AU and that the radio brightness temperature is about 10 billion K. The Harvard patrol plates that provide a photometric history of the star back to 1887 show optical variations but no remarkable activity