{
  "bibcode": "2021GCN.30692....1Z",
  "body": "Z.P. Zhu (NAOC, HUST), L. Izzo (DARK/NBI), S.Y.Fu, D. Xu (NAOC), J.P.U. \nFynbo (DAWN/NBI), E. Paraskeva, S. Vitali (NOT), report on behalf of a \nlarger collaboration:\n\nWe observed the bright optical afterglow of GRB 210822A (Page et al., \nGCN 30677; Wang et al., GCN 30678; Ohno et al., GCN 30687) using the \nNordic Optical Telescope (NOT) equipped with the ALFOSC camera.\n\nWe obtained 3x120s frames in the Sloan r-filter, starting at 23:11:50 UT \non 2021-08-22 (i.e., ~ 13.89 hr after the BAT trigger). The previously \nreported optical afterglow (e.g., Page et al., GCN 30677; Zheng & \nFilippenko, GCN 30679; Butler et al., GCN 30680; Lipunov et al., GCN \n30681; Fu et al., GCN 30684) has decayed to m(r) = 19.71 +/- 0.02, \ncalibrated with the PS1 field.\n\nSubsequently 4x1200 s spectroscopy was carried out. A continuum is \ndetected over the whole wavelength range of 3700-9500 AA, superimposed \nwith some absorption features, among which prominent Fe II, Mg II, Mg I, \nand Al III lines were identified at a common redshift of z = 1.736. We \nconclude that this is the redshift of the burst.",
  "circularId": 30692,
  "createdOn": 1629707152000,
  "email": "dxu@nao.cas.cn",
  "subject": "GRB 210822A: NOT photometry and spectroscopy",
  "submitter": "Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>",
  "eventId": "GRB 210822A"
}