Hi, I heard a lot about GRB221009A in the astronomy community.What is so special about this astrophysical source?
Very good question! GRB 221009A is indeed a very special gamma-ray burst (grb)! It is called the BOAT, for Brightest Of All Times, because it clearly is the brightest burst ever detected. It is also part of the handfull of GRBs that have been detected up to TeV energies: the LHAASO air shower array was able to record the onset and early evolution of this highest energy radiation.
But GRB 221009A is also opening new questions: its afterglow phase did not follow the expected behaviour: no TeV emission was detected by H.E.S.S. a couple of days after the explosion and observations with JWST revealed an unusually weak signal from the supernova that followed the initial GRB.
A special issue of the Astrophysical Journal Letters provides a good overview of the BOAT: Focus on the Ultra-luminous Gamma-Ray Burst GRB 221009A
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Since yesterday, GRB221009A is again on the target list of Astro-Colibri ! But with an error of 0.1368° how can we be sure this is a recurrent event ?
I believe that the GRB 221009A submission yesterday is an error. The alert has been transmitted via the Unistellar citizen science program and is linked to an optical transient detected by ZTF (ZTF24abzmqyb, see for example the Fink portal). I have reached out to Unistellar to get a confirmation that the naming as “GRB221009A” is due to a bug on their side, but I don’t have a confirmation yet.
I’ll rename the event to ZTF24abzmqyb to avoid further confusion …