{
  "bibcode": "2015GCN.17499....1K",
  "body": "N. P. M. Kuin (UCL-MSSL) and M. G. Bernardini (INAF-OAB)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 150222A\n96 s after the BAT trigger (Bernardini et al., GCN Circ. 17486).\nNo optical afterglow consistent with the XRT position (Beardmore et\nal. GCN Circ. 17494) is detected in the initial UVOT exposures.\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_FC            96          246          147         >20.8\nu_FC               308          558          246         >20.7\nwhite               96         6906          746         >21.3\nv                  639         5881          274         >19.9\nb                  564         6702          452         >20.9\nu                  308         6496          678         >20.8\nw1                 689         6292          432         >20.0\nm2                 836         6086          413         >20.4\nw2                1019         6994          297         >20.5\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.05 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 17499,
  "createdOn": 1424695408000,
  "email": "npkuin@gmail.com",
  "subject": "GRB 150222A: Swift/UVOT Upper Limits",
  "submitter": "Paul Kuin at MSSL  <npkuin@gmail.com>",
  "eventId": "GRB 150222A"
}