{
  "bibcode": "2024GCN.37998....1W",
  "createdOn": 1730360999933,
  "subject": "GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart",
  "submitter": "Alan Watson at UNAM <alan@astro.unam.mx>",
  "body": "Alan M. Watson (UNAM), S. Antier (OCA), Stéphane Basa (UAR Pytheas),\nWilliam H. Lee (UNAM), Dahlia Akl (AUS), Jean-Luc Atteia (IRAP), Nathaniel\nR. Butler (ASU), Damien Dornic (CPPM), J.-G. Ducoin (CPPM), Francis Fortin\n(IRAP), Simona Lombardo (LAM), Francesco Magnani (CPPM), and Margarita\nPereyra (UNAM)  report:\n\nWe imaged the field of GRB 241030B detected by Fermi/GBM, Swift/BAT,\nSwift/XRT, and SVOM/ECLAIRs (Fermi GBM Team, GCN Circ. 37980; Klingler et\nal., GCN Circ. 37981; Zhao et al., GCN Circ. 37984) during the\ncommissioning of the COLIBRÍ (SVOM/F-GFT) telescope at the Observatorio\nAstronómico Nacional on the Sierra de San Pedro Mártir in Mexico.\n\nWe observed with the engineering test camera in a red filter that\napproximates SDSS r. We observed from 2024-10-31 03:51 to 05:46 UTC (9.3 to\n11.2 hours after the trigger) and obtained 5160 seconds of exposure. The\ndata were reduced using custom software and then analyzed and calibrated\nagainst the PS1 catalog using the STDWeb service (Karpov et al., 2022).\n\nWe do not detect the optical counterpart (Fu et al., GCN Circ. 37985; Odeh\net al., GCN Circ. 37986; Moskvitin et al., GCN Circ. 37987; Brivio et al.,\nGCN Circ. 37991; Moskvitin et al., GCN Circ. 37995) with a 3-sigma limiting\nAB magnitude of:\n\n    r > 23.2\n\nWe warmly thank the COLIBRÍ engineering team and the staff of the\nObservatorio Astronómico Nacional on the Sierra de San Pedro Mártir.\n",
  "circularId": 37998,
  "eventId": "GRB 241030B",
  "submittedHow": "email-legacy"
}