Radio Outbursts from Cygnus X-3

Abstract

The variation in flux density obtained at 10522 MHz for Bursts 2, 3, and 4 is compared with that obtained by others at frequencies down to 365 MHz. The bursts appear to have a quasi-periodic modulation with a period of 3–4 h, which is different from the 4.8-h periodicity observed at X-ray and infrared wavelengths. The modulation is attributed to a fluctuation in the size of the expanding cloud of particles produced by either an instability in the atmosphere of Cygnus X-3 or by a built-in instability in the cloud itself.