GRB 011211 was detected by the Italian–Dutch X-ray astronomy satellite BeppoSAX on 11 December 2001 at 19:09 UTC.[2] The burst lasted 270 seconds, making it the longest burst that had ever been detected by BeppoSAX up to that point.[3] A spectrum recorded by the Yepun telescope indicated a redshift of z = 2.14.[4]
Supernova relation
A team of researchers at the University of Leicester conducted an analysis of the burst's X-ray afterglow with the XMM-Newton observatory. They found evidence for emission lines of magnesium, silicon, sulphur, and various other chemical elements. This was the first detection of these elements in the spectrum of a GRB.[5] These observations provided strong evidence for a relation between gamma-ray bursts and supernova.[3] However, other astronomers pointed out flaws in the methodology of the Leicester research team, such as the data reduction methods,[6] the low statistical significance of the emission lines,[7] and the low spectral resolution of the instrument used.[8] Despite a follow-up paper from the Leicester team to address these concerns,[9] the findings remained controversial, and GRB 020813 was given the distinction of being the first burst with direct evidence of a supernova relation.[10][11]
Host galaxy
Optical, infrared, and X-ray observations taken by the Hubble Space Telescope between 14 and 59 days after the burst's detection revealed a blue galaxy with an apparent magnitude of 24.95 ± 0.11.[12] Like several other gamma-ray burst hosts, Lyman alpha emission was detected from this galaxy, supporting the theory that the progenitors of gamma-ray burst tend to be metal-poor.[13]
^Butler, Nathaniel R.; et al. (10 November 2003). "The X-ray Afterglows of GRB 020813 and GRB 021004 with CHANDRA HETGS: Possible Evidence for a Supernova Prior to GRB 020813". The Astrophysical Journal. 597 (2): 1010–1016. arXiv:astro-ph/0303539. Bibcode:2003ApJ...597.1010B. doi:10.1086/378511. S2CID6171688.