{
  "circularId": 42857,
  "bibcode": "2025GCN.42857....1G",
  "submittedHow": "web",
  "subject": "GRB 251126A: 1.3m DFOT optical afterglow detection",
  "createdOn": 1764231259759,
  "eventId": "GRB 251126A",
  "body": "Anshika Gupta, Dhruv Jain, Pankaj Pawar, Debalina kar and Kuntal Misra (ARIES) report:\n\n\nWe observed the field of GRB 251126A detected by Swift (Caputo et al. 2025, GCN 42843) with the 1.3m Devasthal Fast Optical Telescope (DFOT), located at the Devasthal Observatory of the Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations were started on   2025-11-26 at 22:17:19 UT, i.e., ~3.11 hour after the Swift trigger. We have taken multiple frames with an exposure time of 300s in the I filter. We stacked the images after the alignment. We detect the optical counterpart in our stacked image within the error box of GIT (Swain et al. 2025, GCN 42844). We obtain the following preliminary magnitude in the stacked image:\n\n\nDate Start_UT T_start-T0 (hour) Filter  Exp time (s)  Magnitude\n======================================================================\n2025-11-26  22:17:19    ~3.11    I     300*12      19.41+/- 0.01\n\n\nOur detection is consistent with Swain et al. 2025 (GCN 42844); Lipunov et al. 2025 (GCN 42847); Fu et al. 2025 (GCN 42848); Reguitti et al. 2025 (GCN 42849); Broens et al. 2025 (GCN 42850); Angulo et al. 2025 (GCN 42855); and Torres et al. 2025 (GCN 42856). \n\nThe magnitude is not corrected for the Galactic extinction in the direction of the burst. \nPhotometric calibration is performed using the standard stars from the USNO-B1 catalog. ",
  "format": "text/plain",
  "submitter": "ANSHIKA GUPTA at ARIES <anshika05180@gmail.com>"
}