Fatal attraction burns bright between star and black hole

A massive, spinning black hole has been caught in the act of tearing apart a star that wandered too close, according to a paper published online in Nature Astronomy this week. This scenario is the latest interpretation behind a bright flare that was detected by an automated telescope in Chile last year.

Astronomers initially classified this event (named ASASSN-15lh) as a supernova explosion - indeed, the most luminous ever observed. However, continued observations led Giorgos Leloudas and colleagues to propose an alternative explanation for the event: a star disintegrating under the gravitational influence of a black hole. Many of these so-called tidal disruption events have been observed previously, but the authors note that this instance would rank as the brightest.

The team undertook a 10-month observing campaign and combined their observations with additional data gathered from the Hubble Space Telescope, the Swift Gamma-Ray Burst Mission and ground-based telescopes. Based on this data, they argue that the flare originated from the very centre of a galaxy - where one would expect a black hole to reside. They also note that the host galaxy’s high mass and lack of current star-forming activity is not consistent with a supernova explanation.