{
  "bibcode": "2025GCN.41450....1S",
  "createdOn": 1755703229754,
  "format": "text/plain",
  "submitter": "Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>",
  "circularId": 41450,
  "eventId": "GRB 250814A",
  "subject": "GRB 250814A: Swift/UVOT Upper Limits",
  "body": "M. H. Siegel (PSU) and R. Caputo (GSFC) report on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 250814A 179 s after the BAT trigger (Caputo et al., GCN Circ. 41358). No optical afterglow consistent with the XRT position (Salvaggio et al., GCN Circ. 41379) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first\nfinding chart (FC) exposure and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nu_FC               179          429          246         >20.3\nwhite              460         1537          264         >21.8\nv                  510         1412           97         >20.2\nb                  436         1511          117         >20.2\nu                  179         1486          343         >20.5\nw1                 560         1462           97         >19.5\nm2                 708         1263           58         >18.6\nw2                 486         1556          130         >20.0\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 1.066 in the direction of the burst\n(Schlegel et al. 1998).",
  "submittedHow": "web"
}