{
  "bibcode": "2020GCN.28851....1O",
  "body": "S. R. Oates (U.Birmingham) and B. Sbarufatti (PSU)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 201104B\n56 s after the BAT trigger (Sbarufatti et al., GCN Circ. 28825).\nA source consistent with the XRT position (Sbarufatti et al. GCN Circ. 28825)\nand UVOT position (Marshall et al. GCN Circ. 28827) is detected in the initial UVOT exposures.\n\nPreliminary detections and 3-sigma upper limits using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: \n\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\nwhite  (FC)         56          206          147         17.98 +/- 0.05\nwhite            20890        21385          484        >21.1\nb                 3718         3777           57        >19.0\nu (FC)             268          459          188         18.72 +/- 0.16\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.048 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 28851,
  "createdOn": 1604655719000,
  "email": "samantha.oates@alumni.ucl.ac.uk",
  "subject": "GRB 201104B: Swift/UVOT Detection",
  "submitter": "Samantha Oates at MSSL  <samantha.oates@alumni.ucl.ac.uk>",
  "eventId": "GRB 201104B"
}