{
  "body": "Paul Kuin (MSSL/UCL) report on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 230812\n25418 s after the GBM trigger (Roberts et al., GCN Circ. 34391).\nThe Fermi LAT also detected the trigger (Scotton et al, GCN Circ. 34392).\nAn candidate optical counterpart was reported (Zheng & Filippenko, GCN\nCirc.\n34395; Lipunov et al., GCN Circ 34396; Salgundi et al., GCN Circ. 34397)\nnear the reported XRT candidate (Kennea, GCN Circ. 34393, Page, GCN Circ.\n34394).  A source consistent with the XRT position is detected in the UVOT\nexposures.\n\nPreliminary detections using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures\nare:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\n\nwhite            25418        31151          390         20.48 +/- 0.18\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.024 in the direction of the burst\n(Schlegel et al. 1998).\n",
  "circularId": 34399,
  "subject": "GRB 230812: Swift/UVOT Detection",
  "submittedHow": "email-legacy",
  "submitter": "Paul Kuin at MSSL <npkuin@gmail.com>",
  "bibcode": "2023GCN.34399....1K",
  "createdOn": 1691917284581,
  "eventId": "GRB 230812"
}