{
  "format": "text/plain",
  "eventId": "GRB 251103A",
  "submittedHow": "web",
  "submitter": "ankur ghosh at CAPP, University of Johannesburg <ghosh.ankur1994@gmail.com>",
  "createdOn": 1762167769018,
  "bibcode": "2025GCN.42545....1G",
  "subject": "GRB 251103A: LCO optical observation",
  "body": "Ankur Ghosh, Soebur Razzaque (CAPP, University of Johannesburg),  Rahul Gupta (NASA GSFC),  Alexander Moskvitin, Yulia Sotnikova (SAO RAS), Naveen Dukiya (ARIES) on behalf of a larger collaboration. \n\nWe observed the field of the GRB 251103A triggered by SVOM/ECLAIRs (Hu et al., GCN 42534) in V and r  filters of  the 1-meter Sinistro telescope at the Las Cumbres Observatory Global Telescope (LCOGT) node located at McDonald Observatory. The 1-m Sinistro telescope is equipped with a 4K x 4K CCD (FOV: 26 x 26 arcmin, scale: 0.39 arcsec/pixel).\n\nObservations began on November 03, 2025, starting from 4.22 hours after the GRB trigger.\n\nWe clearly detect the optical transient (OT) reported by GCNs (Schneider et al., GCN 42535; Turpin et al., GCN 42538; Gritsevich et al., GCN 42539; Izzo et al., GCN 42540, O'Neill et al., GCN 42543) in our V and r band images. \n\n|Date|\t\t|JD start|\t\t|t-T0 (hours)|\t|Exp (sec)|\t|Filter|   |Magnitude|  \n-----------------------------------------------------------------------------------------------------     \n2025-11-03\t2460982.90068\t\t4.226\t\t1 x 500 \tV\t   V = 19.38 +/- 0.08\n2025-11-03\t2460982.90060\t\t4.221\t\t1 x 500\t\tr          r = 19.26 +/- 0.05\n\n\nThe field was calibrated against nearby APASS stars, with magnitudes converted using Lupton (2005) equations, and has not been corrected for Galactic extinction.\n",
  "circularId": 42545
}