{
  "bibcode": "2010GCN.11451....1L",
  "body": "W. Landsman (NASA/Adnet) and T. Sakamoto (NASA/UMBC) report on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 101213A 114 s after the BAT trigger (Sakamoto et al., GCN Circ. 11448).   No optical afterglow consistent with the XRT position (Osborne et al., GCN Circ. 11450) is detected in the initial UVOT exposures.   Preliminary 3-sigma upper limits using the UVOT photometric system  (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)      Mag\n\nwhite_FC           114          264          147>21.0\nu_FC               327          577          246>19.8\nwhite              114         5066          286>21.4\nv                 3919         4119          197>19.2\nb                  583         4940          216>20.5\nu                  327         4733          442>20.4\nw1                4329         4529          197>20.3\nm2                4124         4323          197>20.4\n\nThe values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.06 in the direction of the burst (Schlegel et al. 1998).",
  "circularId": 11451,
  "createdOn": 1292259157000,
  "email": "wayne.b.landsman@nasa.gov",
  "subject": "GRB 101213A: Swift/UVOT Upper Limits",
  "submitter": "Wayne Landsman at GSFC/SSAI  <wayne.b.landsman@nasa.gov>",
  "eventId": "GRB 101213A"
}