Observation of periodic gamma radiation from the discrete source Cygnus X-3
Gal'per A.M. , Kirillov-Ugryumov V.G. , Kurochkin A.V., Leikov N.G., Luchkov B.I., Yurkin Yu.T.
A spark-chamber telescope mounted on high-altitude balloons was used in 1972, 1974, and 1976 to measure fluxes of γ rays of energy exceeding 40 MeV from the discrete source Cygnus X-3. The radiation was found to be variable, with a period 0.199686 of a day coinciding with the χ ray period. The registered у radiation is concentrated in a narrow pulse of duration less than 1 hour, which arises near the minimum of the χ ray flux. The γ ray luminosity of the Cygnus X-3 source is ~ 1038 erg/sec.