{
  "body": "A. A. Breeveld (UCL-MSSL) and N. J. Klingler (GSFC/UMBC/CRESSTII) report on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 241030B 162 s after the BAT trigger (Klingler et al., GCN Circ. 37981).\nThe optical counterpart (Fu et al., GCN Circ. 37985; Odeh et al., GCN Circ. 37986; Moskvitin et al., GCN Circ. 37987; Brivio et al., GCN Circ. 37991;  Moskvitin et.al GCN Circ. 37995 and Qui et al. GCN Circ. 37999) is detected in the initial UVOT exposure in the white filter only.\n\nPreliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\n\nwhite              162          538          167         21.00 ± 0.30\nv                  395         4817          255        >19.4\nb                  494          857           58        >19.3\nu                  469         5380          203        >20.2\nw1                 444         5228          255        >21.1\nm2                4822         5021          197        >19.7\nw2                 371         4612          255        >19.8\n\nThe magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.204 in the direction of the burst (Schlegel et al. 1998).\n",
  "subject": "GRB 241030B: Swift/UVOT Detection",
  "submittedHow": "email",
  "createdOn": 1730379389394,
  "eventId": "GRB 241030B",
  "bibcode": "2024GCN.38008....1B",
  "circularId": 38008,
  "submitter": "Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>"
}