{
  "subject": "GRB 171120A: Swift/UVOT Upper Limits",
  "eventId": "GRB 171120A",
  "bibcode": "2017GCN.22144....1G",
  "createdOn": 1511299280000,
  "circularId": 22144,
  "submitter": "Jeffrey Gropp at PSU  <jdg44@psu.edu>",
  "email": "jdg44@psu.edu",
  "body": "J. D. Gropp (PSU) and A. Tohuvavohu (PSU)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 171120A\n99 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22133).\nNo optical afterglow consistent with the refined XRT position\n(Evans et al. GCN Circ. 22135)\nis 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            99          249          147         >19.9\nu_FC               311          561          246         >19.7\nwhite               99         5989          560         >21.1\nv                  640         6399          413         >19.1\nb                  566         5784          413         >20.9\nu                  311        11713          811         >20.7\nw1                5174        11532         1082         >21.0\nm2                9724        10624          886         >21.0\nw2                4559         6194          393         >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)."
}