Discovery of strong radio flaring from HR 1099

Abstract

A remarkable series of strong radio outbursts was discovered from the RS CVn binary HR 1099 (=V711 Tau) starting on 20 February 1978. The flux density at 10.5 GHz was monitored for nine days at the Algonquin Radio Observatory and whenever possible at 15.5 and 7.9 GHz at Haystack Observatory. These data show, for the first time, detailed temporal development of several RS CVn radio flares. The mechanism of radio emission is almost certainly nonthermal gyrosynchrotron radiation in a volume whose characteristic dimension is several times larger than the stellar size(s) but comparable with the binary star separation.