{
  "bibcode": "2014GCN.17058....1M",
  "body": "F. E. Marshall (NASA/GSFC) and A. Melandri (INAF-OAB)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 141109B\n188 s after the BAT trigger (Melandri et al., GCN Circ. 17038).\nNo optical afterglow consistent with the UVOT-enhanced XRT position\n(Beardmore et al., GCN Circ. 17045)\nis detected in the initial UVOT exposures.\n\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           188          338          147         >20.1\nu_FC               347          596          246         >20.4\nwhite              188         6699          588         >21.3\nv                  677         7110          313         >20.4\nb                  602         6494          294         >21.0\nu                  347        13125         1061         >20.9\nw1                 727        12566         1207         >21.0\nm2                 701         7315          255         >20.8\nw2                 828         6905          255         >21.0\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": 17058,
  "createdOn": 1415660216000,
  "email": "femarsha@khamseen.gsfc.nasa.gov",
  "subject": "GRB 141109B: Swift/UVOT Upper Limits",
  "submitter": "Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>",
  "eventId": "GRB 141109B"
}