{
  "bibcode": "2018GCN.23055....1R",
  "body": "A. Rossi (INAF-OAS), L. Izzo (HETH/IAA-CSIC), B. Milvang-Jensen\n(DAWN/NBI), D. A. Perley (LJMU), A. de Ugarte Postigo (HETH/IAA-CSIC and\nDARK/NBI), D. A. Kann (HETH/IAA-CSIC), A. J. Levan (U. Warwick), N. R.\nTanvir (U. Leicester), S. Covino (INAF/Brera), and D. B. Malesani\n(DAWN/NBI and DARK/NBI) report on behalf of the Stargate collaboration:\n\nWe observed the optical counterpart of GRB 180728A (Starling et al., GCN\n23046; Lipunov et al., GCN 23048) with the ESO VLT UT2 equipped with the\nX-shooter spectrograph.  One 600 s spectrum was taken during evening\ntwilight on 2018 July 28 beginning at 23:13 UT, plus two additional 600\ns spectra on 2018 July 29 beginning at 05:10 UT.  The spectra cover a\nwavelength range from 3000-25000 AA.\n\nA red continuum is detected across the spectral range. We detect\nabsorption features due to Mg II (3124,3132), Mg I (3187), and Ca II\n(4395,4434) at a consistent redshift of z=0.117, which we propose as the\nredshift of the GRB.  Galactic ISM absorption features of Ca II and Na I\nare also detected.\n\nThis GRB resembles the famous GRB 030329, but slightly less energetic\n(E_iso = 2e+51 erg given the fluence value provided by Veres et al., GCN\n23053).  It is the closest energetic (E_iso > 1e+51 erg) GRB with a\nmeasured redshift to date.\n\nWe note that although Galactic extinction in this direction is\nsignificant (A_V = 0.763; Schlafly et al. 2011, ApJ 737:103) a campaign\nto study the anticipated associated supernova should still be practical\nwith moderate-aperture telescopes at this redshift.\n\nWe acknowledge the ESO observing staff at Paranal, in particular Pascale\nHibon and R. Thomas.\n\n________________________________\nImportant Notice: the information in this email and any attachments is for the sole use of the intended recipient(s). If you are not an intended recipient, or a person responsible for delivering it to an intended recipient, you should delete it from your system immediately without disclosing its contents elsewhere and advise the sender by returning the email or by telephoning a number contained in the body of the email. No responsibility is accepted for loss or damage arising from viruses or changes made to this message after it was sent. The views contained in this email are those of the author and not necessarily those of Liverpool John Moores University.",
  "circularId": 23055,
  "createdOn": 1532888606000,
  "email": "d.a.perley@ljmu.ac.uk",
  "subject": "GRB 180728A: VLT/X-shooter redshift of a nearby energetic GRB",
  "submitter": "Daniel Perley at Liverpool JMU  <d.a.perley@ljmu.ac.uk>",
  "eventId": "GRB 180728A"
}