{
  "body": "Anshika Gupta, Kumar Pranshu, Dhruv Jain, Debolina Kar, Pankaj Pawar, and Kuntal Misra (ARIES) report:\n\n\nWe observed the field of GRB 251025B detected by SVOM/ECLAIRs (Hussein et al. 2025; GCN 42437) \nwith the 3.6m Devasthal Optical Telescope (DOT), located at the Devasthal Observatory\nof the Aryabhatta Research Institute of Observational Sciences (ARIES), India. \nThe observations were started on  2025-10-27 at 04:20:49.73 UT, i.e., ~1.58 days after \nthe SVOM trigger. We have taken multiple frames with an exposure time of 300s in the \nR filter. We stacked the images after the alignment.\nWe detect an optical counterpart in our stacked image within the error box of SVOM \ntelescope (Hussein et al. 2025; GCN 42437) and Swift-XRT (Beardmore et al. 2025; GCN 42445). \nWe obtain the following preliminary magnitude in the stacked image:\n\n\nDate Start_UT T_start-T0 (days) Filter  Exp time (s)  Magnitude\n==================================================================\n 2025-10-27 04:20:49.73   ~1.58  ~   R     300s*8    20.866 +/-0.007\n\n\nOur detection is consistent with  Wu et al. 2025 (GCN 42438);  Gress et al. 2025 (GCN 42439); \nWu et al. 2025 (GCN 42440);  Beardmore et al. 2025 (GCN 42445); Mohan et al. 2025 (GCN 42447); \nHernández Fung et al. 2025 (GCN 42450); Pereyra et al. 2025 (GCN 42452); Li et al. 2025 (GCN 42453);\nMo et al. 2025 (GCN 42459); Rakotondrainibe et al. 2025 (GCN 42460); Rajabov et al. 2025 (GCN 42466); Saccardi et al. 2025 (GCN 42472); Freeberg et al. 2025 (GCN 42474); Volnova et al. 2025 (GCN 42475).\n\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-B1.0 catalog. \n",
  "bibcode": "2025GCN.42500....1G",
  "createdOn": 1761636928525,
  "eventId": "GRB 251025B",
  "subject": "GRB251025B: 3.6m DOT Optical Observations",
  "submittedHow": "web",
  "format": "text/plain",
  "submitter": "ANSHIKA GUPTA at ARIES <anshika05180@gmail.com>",
  "circularId": 42500
}