{
  "body": "A. A. Breeveld (UCL-MSSL) and R. Brivio (INAF-OAB) report on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of SVOM/ECLAIRs detected burst GRB 250205A 4593 s after the trigger (Saccardi et al., GCN Circ. 39154).\nThe afterglow reported by Gompertz et al., GCN Circ. 39156, Schneider & Adami, GCN Circ. 39157, Palmerio et al., GCN Circ. 39159, de Ugarte Postigo et al., GCN Circ. 39160, Kennea et al., GCN Circ. 39161 and Watson et al., GCN Circ. 39162, is not detected in the single U-band exposure.\n\nPreliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposure is:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nu              4593         6243           1625          >20.9\n\nThe magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.046 in the direction of the burst (Schlegel et al. 1998).\n",
  "eventId": "GRB 250205A",
  "subject": "GRB 250205A: Swift/UVOT Upper Limits",
  "submitter": "Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>",
  "submittedHow": "email",
  "circularId": 39168,
  "createdOn": 1738844483429,
  "bibcode": "2025GCN.39168....1B"
}