{
  "circularId": 38702,
  "body": "Ankur Ghosh, Soebur Razzaque (CAPP, University of Johannesburg), Alexander Moskvitin, Yulia Sotnikova (SAO RAS), Naveen Dukiya (ARIES), Rahul Gupta (NASA GSFC) on behalf of a larger collaboration.\n \nWe observed the field of the GRB 241228B triggered by Fermi (Fermi GBM team, GCN 38682) in B  filter of  the 1-meter Sinistro telescope at the Las Cumbres Observatory Global Telescope (LCOGT) node located at Siding Spring New South Wales, Australia. The 1-m Sinistro telescope is equipped with a 4K x 4K CCD (FOV: 26 x 26 arcmin, scale: 0.39 arcsec/pixel).\nObservations began on December 28, 2024, starting from 10.97 hours after the GRB trigger.\n\nWe clearly detect the optical transient (OT) reported by GCNs (Kumar et al., GCN 38684 and GCN 38691, An et al. GCN 38687)  in our B band image. \n\nDate\t\tUTstart\t \tJD\t\t \t\tt-T0 (hours)\tExp (sec)\tFilter\t\tMagnitude       \n2024-12-28\t15:11:37.24\t2460673.13307\t\t\t10.97\t\t1 x 1200 \tB\t\tB = 21.35 +/- 0.03\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\n",
  "subject": "GRB 241228B: LCO optical observation",
  "submittedHow": "web",
  "submitter": "ankur ghosh at CAPP, University of Johannesburg <ghosh.ankur1994@gmail.com>",
  "version": 2,
  "bibcode": "2024GCN.38702....1G",
  "format": "text/plain",
  "editedBy": "Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of ankur ghosh at CAPP, University of Johannesburg <ghosh.ankur1994@gmail.com>",
  "eventId": "GRB 241228B",
  "editedOn": 1735567791159,
  "createdOn": 1735443355483
}