{
  "submitter": "Amit Kumar Ror at ARIES <mitturor77894@gmail.com>",
  "eventId": "GRB 240411B",
  "body": "Amit K. Ror, Anshika Gupta, Rahul Gupta, Amar Aryan, Saurabh, and Shashi B.\nPandey (ARIES) report:\n\n\nWe observed the field of GRB 240411B detected by Swift (Parsotan et al.,\n2024 GCN 36063) with the 1.3m Devasthal Fast Optical Telescope (DFOT),\nlocated at the Devasthal Observatory of the Aryabhatta Research Institute\nof Observational Sciences (ARIES), India. The observations were started on\n2024-04-11 at 19:06:28 UT, i.e., ~ 3.56 hours after the BAT trigger. We\nhave taken multiple frames with an exposure time of 300 s in the R filter.\nWe stacked the images after the alignment. We clearly detected an optical\nafterglow (Izzo et al., 2024, GCN 36064; Schneider et al., 2024, GCN 36067)\nin our final stacked image within the error box of enhanced Swift-XRT\nobservation (Goad et al., 2024, GCN 36065). The estimated preliminary\nmagnitude is as follows:\n\n\nDate Start_UT T_start-T0 (hours) Filter  Exp time (s)  Limiting magnitude\n\n=======================================================\n\n2024-04-11 19:06:28 UT    3.56     R     300*15     22.34 +/- 0.11\n\n\nThe detection of the afterglow is consistent with the observations of Izzo\net al. 2024, GCN 36064, and Schneider et al. 2024, GCN 36067.\n\n\nThe given magnitude value is not corrected for the Galactic and host\nextinctions in the direction of the GRB afterglow. Photometric calibration\nis performed using the standard stars from the USNO-B1.0 catalog. This\ncircular may be cited.\n",
  "createdOn": 1712919144198,
  "submittedHow": "email",
  "circularId": 36069,
  "bibcode": "2024GCN.36069....1R",
  "subject": "GRB 240411B: 1.3m DFOT Optical observations"
}