GRB 111209A explained

GRB 111209A is the longest lasting gamma-ray burst (GRB) detected by the Swift Gamma-Ray Burst Mission, observed on December 9, 2011.^[1] Its duration is longer than 7 hours, implying this event has a different kind of progenitor than normal long GRBs. It was first proposed that the progenitor of this event was a blue supergiant star with low metallicity. Later, it was also proposed that this event is the prototype of a new class of GRBs, ultra-long GRBs.

The GRB was associated with the magnetar-powered supernova 2011kl, an object of intermediate luminosity between conventional GRB supernovae and superluminous supernovae.^[2]

See also

• List of gamma-ray bursts
• Supermassive black hole
• Tidal force

Notes and References

1. 766. 1. 30. Gendre, B. . Stratta, G. . Atteia, J. L. . Basa, S. . Boër, M. . Coward, D. M. . Cutini, S. . D'Elia, V. . Howell, E. J. . Klotz, A. . Piro, L. . The Ultra-long Gamma-Ray Burst 111209A: The Collapse of a Blue Supergiant?. Astrophysical Journal. 2013. 10.1088/0004-637X/766/1/30. 1212.2392. 2013ApJ...766...30G. 118618287.
2. Greiner. J.. etal. 2015. A very luminous magnetar-powered supernova associated with an ultra-long γ-ray burst. Nature. 523. 7559. 189–192. 10.1038/nature14579. 26156372. 1509.03279 . 2015Natur.523..189G . 4464998.