{
  "body": "S.P.R. Shilling (Lancaster U.) reports on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 251016A,\ndetected by SVOM/ECLAIRs (Basa et al., GCN Circ. 42308) and Fermi/GBM\n(Fermi GBM team, GCN Circ. 42309), 6.66 ks after the SVOM/ECLAIRs trigger.\n\nA source is detected in the optical by the Swift/UVOT at a position that is\nconsistent with the likely X-ray counterpart detected by the Swift/XRT\n(Source 1: Evans et al., GCN Circ. 42311). \n\nPreliminary detections and upper limits using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the images are:\n\nFilter         T_start(ks)   T_stop(ks)      Exp(s)            Mag\n\nu\t       6.66\t     12.6\t     491.7\t       19.13 +/- 0.26\nb\t       6.91\t     12.7\t     296.0\t       18.70 +/- 0.18\nv\t       7.42\t     7.67\t     245.8\t       17.52 +/- 0.15\nw1\t       12.1\t     12.4\t     245.8\t       >18.93\nw2\t       7.17\t     7.42\t     245.8\t       >19.05\nm2\t       7.68\t     7.85\t     168.3\t       >18.66\n\nThe magnitudes reported here are not corrected for Galactic extinction.\n",
  "submitter": "s.shilling@lancaster.ac.uk",
  "eventId": "GRB 251016A",
  "bibcode": "2025GCN.42354....1S",
  "subject": "GRB 251016A: Swift/UVOT Detection",
  "circularId": 42354,
  "createdOn": 1760789109883,
  "submittedHow": "web",
  "format": "text/plain"
}