{
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Daniele B. Malesani at IMAPP / Radboud University <d.malesani@astro.ru.nl>",
  "submittedHow": "email",
  "editedOn": 1745242135918,
  "bibcode": "2025GCN.40185....1K",
  "body": "Paul Kuin (MSSL/UCL) reports on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began observations of the field of SVOM detected GRB\n250419A/(SVOM burst-id sb25041901) 3790s after the SVOM ECLAIR\ntrigger at 2025-04-19T02:29:32 (Wang et al., GCN Circ. 40168).\nA source consistent with the position reported by Kin Ocelotl López\net al. (Colibri - GCN Circ. 40169) and Liping Xin at al. (SVOM-VT\nGCN Circ 40170), also reported by Weikang Zheng et al. (KAIT - GCN\nCirc. 40171) and Amit Kumar et al. (GCN Circ. 40172) has been\ndetected in the initial UVOT exposures.\n\nThe detections using the UVOT photometric system (Breeveld et al.\n2011, AIP Conf. Proc. 1358, 373) for the early exposures are:\n\nFilter         T_start(s)       Exp(s)         Mag (Vega)\n\nu                 3790          1667         17.73 +/- 0.04\nu                 9323           259         18.19 +/- 0.10\nu                48658          1206         19.64 +/- 0.14\nu                54296          1028         19.52 +/- 0.13\n\nThe magnitudes in the table are not corrected for the Galactic\nextinction due to the reddening of E(B-V) = 0.085 in the direction\nof the burst (Schlegel et al. 1998).\n",
  "version": 2,
  "createdOn": 1745152797295,
  "submitter": "Paul Kuin at MSSL <npkuin@gmail.com>",
  "subject": "GRB 250419A: Swift/UVOT Follow up",
  "circularId": 40185,
  "eventId": "GRB 250419A",
  "format": "text/plain"
}