{
  "bibcode": "2020GCN.28827....1M",
  "body": "F. E. Marshall (NASA/GSFC), S. R. Oates (U.Warwick) and B. Sbarufatti (PSU)\r\n\r\nreport on behalf of the Swift/UVOT team:\r\n\r\n\r\n\r\nThe Swift/UVOT began settled observations of the field of GRB 201104B\r\n\r\n56 s after the BAT trigger (Sbarufatti et al., GCN Circ. 28825).\r\n\r\nA source consistent with the XRT position\r\n\r\n(Sbarufatti et al. GCN Circ. 28825)\r\n\r\nis detected in the initial UVOT exposures.\r\n\r\n\r\n\r\nThe preliminary UVOT position is:\r\n\r\n    RA  (J2000) =  00:20:51.65 =   5.21520 (deg.)\r\n\r\n    Dec (J2000) = +07:50:29.4  =   7.84150 (deg.)\r\n\r\nwith an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).\r\n\r\n\r\n\r\nPreliminary detections using the UVOT photometric system\r\n\r\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:\r\n\r\n\r\n\r\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\r\n\r\n\r\n\r\nwhite               56          206          147         18.63 +/- 0.06\r\n\r\nu                  268          459          188         19.45 +/- 0.23\r\n\r\n\r\n\r\nThe magnitudes in the table are not corrected for the Galactic extinction\r\n\r\ndue to the reddening of E(B-V) = 0.045 in the direction of the burst\r\n\r\n(Schlegel et al. 1998).",
  "circularId": 28827,
  "createdOn": 1604520969000,
  "email": "marshall@milkyway.gsfc.nasa.gov",
  "subject": "GRB 201104B: Swift/UVOT Detection",
  "submitter": "Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 201104B"
}