{
  "format": "text/plain",
  "circularId": 39762,
  "eventId": "GRB 250316A",
  "subject": "GRB 250316A: Swift/UVOT Upper Limits",
  "submitter": "Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>",
  "bibcode": "2025GCN.39762....1S",
  "createdOn": 1742218017988,
  "submittedHow": "web",
  "body": "M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team:\n\nSwift/UVOT observed the field of GRB250316A (GCN 39737) for a total of 3.3 ks\nin the white filter from 21.8 ks to 29 ks after the Fermi trigger. We detect no optical/UV source at the position of the XRT afterglow (Beardmore et al., GCN Circ. 39758) to an upper limit of white > 22.53. The magnitude is not corrected for the Galactic extinction due to the reddening\nof E(B-V) = 0.017 in the direction of the burst (Schlegel et al. 1998)."
}