{
  "bibcode": "2022GCN.32648....1D",
  "body": "A. de Ugarte Postigo (OCA), L. Izzo (DARK/NBI), G. Pugliese \n(Amsterdam Univ. and Leiden Observatory), D. Xu (NAOC), \nB. Schneider (CEA Paris-Saclay), J.P.U. Fynbo (DAWN/NBI), \nN.R. Tanvir (Univ. Leicester), D.B. Malesani (Radboud Univ. \nand DAWN/NBI), A. Saccardi (GEPI, Observatoire de Paris),  \nD. A. Kann (Goethe Univ.), K. Wiersema (Lancaster Univ.), \nB. P. Gompertz (Birmingham), C. C. Thoene (ASU-CAS) and \nA. J. Levan (Radboud Univ.) report on behalf of the Stargate \ncollaboration:\n\nWe observed the afterglow of the extremely bright GRB221009A \n(Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; \nBissaldi et al., GCN 32637; Veres et al., GCN 32636; Lesage et \nal., GCN 32642) with X-shooter at ESO's UT3 of the Very Large \nTelescope (Paranal, Chile). The observations started at \n00:49:58.9 UT  (11.55 hr after the GBM trigger and 10.66 hr \nafter the BAT trigger). The observation consisted of 4x600s with \na spectral coverage between 3000 and 21000 AA.\n\nWe detect a very red continuum with absorption features that \ncorrespond to CaII, CaI and NaID at a redshift of z = 0.151. We \nalso detect multiple features due to the Milky Way���s interstellar \nmedium, due to the large Galactic column density of material \nalong this line of sight. At this redshift the event has an isotropic \nequivalent energy of Eiso=2x10^54 erg (using the GBM fluence \nreported in GCN 32642), barring saturation effects in the \nFermi/GBM fluence. This is within the upper end of GRB \nenergetics. Further follow-up is strongly encouraged.\n\nWe acknowledge the excellent support provided by the Paranal \nstaff, in particular A. Escorza and Zahed Wahhaj.",
  "circularId": 32648,
  "createdOn": 1665394781000,
  "email": "deugarte@oca.eu",
  "subject": "GRB 221009A: Redshift from X-shooter/VLT",
  "submitter": "Antonio de Ugarte Postigo at OCA  <deugarte@oca.eu>",
  "eventId": "GRB 221009A"
}