{
  "circularId": 34643,
  "bibcode": "2023GCN.34643....1O",
  "eventId": "GRB 230906A",
  "submittedHow": "email",
  "submitter": "Samantha Oates at University of Birmingham <samantha.oates@alumni.ucl.ac.uk>",
  "subject": "GRB 230906A: Swift/UVOT Upper Limits",
  "body": "S. R. Oates (Lancaster U. ) and M. J. Moss (GSFC)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 230906A\n93 ks after IPN-detection (Kozyrev et al., GCN Circ 34637). No optical\nafterglow consistent with the XRT position  (Beardmore et al., GCN\nCirculars 34639), is detected in the initial UVOT exposures.\n\nPreliminary 3-sigma upper limits using the UVOT photometric system\n(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\nwhite            93297        106009        4648          >22.8\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.021 in the direction of the burst\n(Schlegel et al. 1998).\n",
  "createdOn": 1694256796212
}