{
  "body": "Amit K. Ror, Shashi B. Pandey, Rahul Gupta, and Amar Aryan, Shivangi Pandey\n(ARIES) report:\n\n\nWe observed the field of GRB 240225B detected by MAXI (Nakajima et al.\n2024, GCN 35796), Swift (Evans 2024, GCN 35797), and AstroSat (Joshi et al.\n2024, GCN 35798) using the 3.6m Devasthal Optical Telescope of ARIES\nNainital. The observations were started on 2024-02-28 at 01:04:01.085 UT,\ni.e., 2.2 days after the MAXI trigger. We have taken multiple frames with a\n60-second exposure time in the r, i, and z filters. We detected the OT at\nthe position of the GOTO afterglow candidate reported by Gompertz et al.\n(2024, GCN 35805) in each observed image in the i and z bands and the\nstacked image of the r band, indicating a redder nature. The preliminary\nmagnitude measurements are as follows:\n\n\nDate Start_UT T_start-T0 (days) Filter  Exp time (s)  Limiting magnitude\n\n=========================================================\n\n2024-02-28 01:04:01.085     2.2     i     60s     19.96 +/- 0.04\n\n\nOur i-band observation, combined with the observation of Wise et al. (2024,\nGCN 35820), yielded a decay index of ~ 0.8 in the i-band.\n\nThe magnitude quoted is not corrected for the host and Galactic extinction\nin the direction of the burst. Photometric calibration is performed using\nthe standard stars from the Pan-STARRS catalog.\n\n\nOur detection is consistent with Gompertz et al. 2024, GCN 35805; Liu et\nal. 2024, GCN 35812; Malesani et al. 2024, GCN 35819; Wise et al. 2024, GCN\n35820; Gompertz et al. 2024, GCN 35824; Pankov et al. 2024, GCN 35826;\nMoskvitin et al. 2024, GCN 35828; and Geoffrey et al. 2024, GCN 35829.\n\n\nThis circular may be cited. 3.6m Devasthal Optical Telescope (DOT) is a\nrecently commissioned facility in the Northern Himalayan region of India\n(long:79 41 04E, lat:29 21 40N, alt:2540m) owned and operated by the\nAryabhatta Research Institute of Observational Sciences (ARIES), Nainital (\nhttps://www.aries.res.in). Authors of this GCN circular thankfully\nacknowledge consistent support from the staff members to run and maintain\nthe 3.6m DOT.\n",
  "submitter": "Amit Kumar Ror at ARIES <mitturor77894@gmail.com>",
  "createdOn": 1709187359478,
  "eventId": "GRB 240225B",
  "subject": "GRB 240225B: 3.6m DOT observation",
  "circularId": 35830,
  "bibcode": "2024GCN.35830....1R",
  "submittedHow": "email"
}