  I point to an interesting similarity in the radio and the soft X-ray light
curves between the November 2009 outburst of the X-ray binary Aquila X-1 and
some solar flares. The ratio of the soft X-ray and radio luminosities of Aquila
X-1 in that outburst is also similar to some weak solar flares, and so is the
radio spectrum near 8 GHz. Based on these, as well as on some other recent
studies that point to some similar properties of accretion disk coronae and
stellar flares, such as ratio of radio to X-ray luminosities (Laor & Behar
2008), I speculate that the soft X-ray outburst of Aquila X-1 was related to a
huge magnetic flare from its disk corona.
