{
  "subject": "GRB 130912A: Swift/UVOT Upper Limits",
  "eventId": "GRB 130912A",
  "bibcode": "2013GCN.15229....1C",
  "createdOn": 1379278331000,
  "circularId": 15229,
  "submitter": "Margaret Chester at PSU  <chester@astro.psu.edu>",
  "email": "chester@astro.psu.edu",
  "body": "M. M. Chester (PSU) and V. D'Elia (ASDC) report on behalf of the \nSwift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 130912A\n99 s after the BAT trigger (D'Elia et al., GCN Circ. 15212).\nNo optical afterglow consistent with the enhanced XRT position \n(Beardmore et al. GCN Circ. 15217) is detected in the initial UVOT \nexposures. Preliminary 3-sigma upper limits using the UVOT photometric \nsystem (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first\nfinding chart (FC) exposures and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nwhite_FC            99          249          147         >20.7\nu_FC               311          561          246         >20.2\nwhite               99         6848          785         >21.4\nv                  640        23984         1395         >20.3\nb                  566        30470         1907         >21.6\nu                  311        36236         3907         >21.6\nw1                 690        35508         3836         >22.1\nm2                1070        34601         2827         >21.8\nw2                 616        23070         1376         >21.6\n\nThe magnitudes in the table are not corrected for the Galactic \nextinction due to the reddening of E(B-V) = 0.28 in the direction \nof the burst (Schlegel et al. 1998)."
}