{
  "bibcode": "2015GCN.17785....1C",
  "body": "M. M. Chester (PSU) and K. L. Page (U Leicester)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 150428A\n179 s after the BAT trigger (Page et al., GCN Circ. 17765).  No optical \nafterglow consistent with the enhanced XRT position (Osborne et al. GCN\nCirc. 17768) 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 one subsequent exposure are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)     UL (3-sigma)\n\nwhite_FC           179         329          147        >20.9\nu                 3572        3726          152        >19.9\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.02 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 17785,
  "createdOn": 1430268225000,
  "email": "chester@swift.psu.edu",
  "subject": "GRB 150428A: Swift/UVOT Upper Limits",
  "submitter": "Margaret Chester at PSU  <chester@swift.psu.edu>",
  "eventId": "GRB 150428A"
}