{
  "bibcode": "2018GCN.23112....1G",
  "body": "C. Guidorzi, R. Martone (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell \n(U. Bath), A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU), A. Cucchiara, \nD. Morris (U. of Virgin Islands) on behalf of a large collaboration report:\n\nWe observed Swift GRB 180809B (Moss et al. GCN 23105) with the LCO 1-m \nunits at Sutherland Observatory (South Africa) on August 09, from 20:58 \nto 22:29 UT (corresponding to 0.5 to 2.0 hours from the GRB trigger \ntime) with the SDSS r' and i' filters. We clearly detect the optical \nafterglow (Moss et al; Lipunov et al. GCN 23109; Watson et al. GCN \n23110; Schweyer et al. GCN 23111) in both filters with the following \nmagnitudes:\n\nMid time from GRB���������� Exposure���������������� Filter Magnitude\ntrigger time (hrs)�������� (s)\n---------------------------------------------------------------------\n0.55������������������������������������ 5x60������������������������ SDSS r'���������������� 19.54 +- 0.08\n0.70������������������������������������ 5x60������������������������ SDSS i'���������������� 19.24 +- 0.07\n---------------------------------------------------------------------\n\nas calibrated against nearby Pan-STARRS objects.",
  "circularId": 23112,
  "createdOn": 1533891596000,
  "email": "guidorzi@fe.infn.it",
  "subject": "GRB 180809B: LCO Sutherland observations",
  "submitter": "Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>",
  "eventId": "GRB 180809B"
}