{
  "bibcode": "2015GCN.17411....1B",
  "body": "A. Breeveld (MSSL-UCL), D. Malesani (DARK/NBI) and B. Sbarufatti \n(INAF-OAB/PSU) report on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT observed the field of GRB 150204A during follow-up \nobservations, 51182 s after the BAT trigger (Cummings et al. GCN Circ. \n17404). No optical afterglow consistent with the possible XRT \ncounterpart (A. Melandri et al. GCN Circ. 17409) is detected in the \ninitial UVOT exposures.\nPreliminary 3-sigma upper limits using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial \nexposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nv                57368        58276          885         >19.5\nu                52088        52670          568         >19.5\nw1               51182        63642         1495         >20.3\nm2               58281        63016         1027         >20.1\nw2               56461        57361          886         >19.9\n\nThe magnitudes in the table are not corrected for the Galactic \nextinction due to the reddening of E(B-V) = 0.824 in the direction of \nthe burst (Schlegel et al. 1998).",
  "circularId": 17411,
  "createdOn": 1423154554000,
  "email": "a.breeveld@ucl.ac.uk",
  "subject": "GRB 150204A: Swift/UVOT Upper Limits",
  "submitter": "Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>",
  "eventId": "GRB 150204A"
}