{
  "createdOn": 1789686949348,
  "submitter": "Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek@asu.cas.cz>",
  "body": "Martin Jelinek, Jan Strobl and Filip Novotny \n(ASU CAS Ondrejov, CZ),\n\nMartin Masek, Sergey Karpov, Petr Janecek, Jakub Jurysek, \nJan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza \n(Institute of Physics, Prague, CZ)\n\nreport:\n\nThe 30cm robotic telescope FRAM-Auger at the Pierre Auger\nObservatory (Cerro Los Leones, Malargue, Argentina) reacted\nrobotically to the alert of GRB 260917B (He et al., GCN\n45606), obtaining a series of R-band images starting at\n04:04:32 UT, i.e. ~12 min post trigger, at an elevation of\nonly 7-9 deg. A second series was obtained about two hours\nafter the trigger, when the field had risen higher.\n\nWe do not detect the optical counterpart reported by Dornic\net al. (GCN 45607), Yin et al. (GCN 45608), Ma et al. (GCN\n45610) and Mohan et al. (GCN 45611), neither in single\nimages nor in the combined frames, with the following\nlimits:\n\nT-T0[mid]  Images  Span[s]  Limit (Vega)\n~17 min    9       630      R_C > 17.0\n~116 min   11      767      R_C > 17.9\n\nThe photometry is calibrated against the Atlas-REFCAT2\ncatalogue (Tonry et al. 2018, ApJ, 867, 105) and is not\ncorrected for Galactic extinction. The early limit implies\nthat this faint burst was not accompanied by a bright\noptical flash or strong flaring activity.\n",
  "eventId": "GRB 260917B",
  "submittedHow": "email",
  "subject": "GRB 260917B: FRAM-Auger optical limits",
  "circularId": 45617
}