{
  "bibcode": "2020GCN.28661....1I",
  "body": "L. Izzo (DARK/NBI), D. B. Malesani (DTU Space), Z.P. Zhu (NAO/CAS, \nHUST), D. Xu (NAO/CAS), A. de Ugarte Postigo (HETH, IAA-CSIC), T. \nPursimo, report on behalf of a larger collaboration:\n\nWe observed the optical counterpart of GRB 201015A (D'Elia et al., GCN \n28632; Lipunov et al., GCN 28634) with the Nordic Optical Telescope, \nequipped with the ALFOSC spectrograph. Spectroscopic observations \nstarted on 2020 Oct 15.978 UT (38 min after the GRB trigger) and \nconsisted of four 900-s exposures with grism #4, covering the wavelength \nrange 3800-9400 AA.\n\nA trace is visible across the full spectral range. In the blue part, \nweak absorption features are detected which can be interpreted as Mg II, \nMg I and Ca II at z = 0.423. Faint emission lines are also detected at a \nconsistent redshift, identified as [O II] and Halpha. Our data allow \nthus to confirm the redshift value reported by de Ugarte Postigo et al. \n(GCN 28649) using the GTC. We note that the detection of absorption \nfeatures sets a firm lower limit to the GRB redshift, excluding a chance \nsuperposition with a background galaxy.\n\nThis work made use of the GRBspec database grbspec.iaa.es.",
  "circularId": 28661,
  "createdOn": 1602872126000,
  "email": "malesani@space.dtu.dk",
  "subject": "GRB 201015A: redshift confirmation",
  "submitter": "Daniele B Malesani at DTU Space  <malesani@space.dtu.dk>",
  "eventId": "GRB 201015A"
}