{
  "bibcode": "2013GCN.15605....1D",
  "body": "V. D'Elia (ASDC) and F.E. Marshall (NASA/GSFC)\nreport on behalf of the Swift team:\n\n\nWe report on Swift observations of the field of the INTEGRAL discovered GRB131218A (Gotz et al. GCN Circ 15601), starting 17.5 hours after the trigger. Due to an observing constraint, only a very short exposure was carried out.\n\nXRT began observing the field on 2013-12-19 at 14:32:15 UT, i.e.,  62803 s after the trigger, for a total of 99 s. No source is detected within the INTEGRAL error circle. The 3-sigma upper limit on the count rate is ~9E-02 cts/s.\n\nThe Swift/UVOT began settled observations of the field of GRB 131218A 62782 s after the trigger. No optical afterglow consistent with the optical position (Klotz et al., GCN Circ. 15603) is detected in the initial UVOT exposure.\nThe preliminary 3-sigma upper limit using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposure is:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nv                62782        62900          116         >19.8\n\nThe magnitude in the table is not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.17 in the direction of the burst (Schlegel et al. 1998).",
  "circularId": 15605,
  "createdOn": 1387553547000,
  "email": "delia@asdc.asi.it",
  "subject": "GRB 131218A: Swift XRT and UVOT observations",
  "submitter": "Valerio D'Elia at ASDC  <delia@asdc.asi.it>",
  "eventId": "GRB 131218A"
}