{
  "bibcode": "2022GCN.31359....1F",
  "body": "J. P. U. Fynbo (DAWN/NBI), A. de Ugarte Postigo (Obs. Cote d'Azur), D. \nXu (NAOC), D. B. Malesani (Univ. Radobud and DAWN/NBI), B. \nMilvang-Jensen (DAWN/NBI), J. Viuho (NOT and DAWN/NBI), report on behalf \nof a larger collaboration:\n\nWe observed the optical counterpart of GRB 220101A (Tohuvavohu et al., \nGCN 31347; Arimoto et al., GCN 31350) using the Nordic Optical Telescope \n(NOT) equipped with the ALFOSC spectrograph. A spectrum with exposure \ntime 4x1200 s (grism #20) was secured starting on 2022 Jan 1.81 UT (14.3 \nhr after the GRB), under good conditions, and covering the wavelength \nrange 5600-10200 AA.\n\nA very clear trace is detected from the afterglow continuum. A deep, \nbroad trough is detected around 6800 AA, which we interpret as due to \ndamped Lyman alpha. A number of narrow absorption features are also \nclearly visible and allow to determine accurately the GRB redshift. We \nidentify, among others, N V, S II, Si II, Si II*, O I, Ni II, C II, Si \nIV, C IV, Fe II, Fe II*, and Al II, all at a common redshift z = 4.618. \nOur results thus fully confirm the finding of Fu et al. (GCN 31353).\n\nNice year start for GRBs: happy 2022 to all GCN readers!",
  "circularId": 31359,
  "createdOn": 1641080606000,
  "email": "d.malesani@astro.ru.nl",
  "subject": "GRB 220101A: NOT redshift confirmation",
  "submitter": "Daniele B Malesani at Radboud U  <d.malesani@astro.ru.nl>",
  "eventId": "GRB 220101A"
}