Enhanced emission from GRB 110328A could be evidence for tidal disruption of a star

Abstract

On March 28, Swift's Burst Alert Telescope discovered a source in the constellation Draco when it erupted in a series of X-ray blasts. The explosion, catalogued as gamma-ray burst (GRB) 110328A, repeatedly flared in the following days, making the interpretation of the event as a GRB unlikely. Here we suggest that the event could be due to the tidal disruption of a star that approaches the pericentric distance of a black hole, and we use this fact to derive bounds on the physical characteristics of such system, based on the variability timescales and energetics of the observed X-ray emission.