{
  "bibcode": "2011GCN.12631....1W",
  "body": "C. A. Wolf (PSU), E. A. Hoversten (PSU), and T. Sakamoto (GSFC/UMBC)  \nreport on behalf of the Swift team:\n\nWe have analyzed 2.85 ks of XRT data for the BAT ground-detected  \nburst: GRB 111208A (Sakamoto et. al. GCN Circ. 12628), from 24.3 ks to  \n34.9 ks after the burst. The data are entirely in Photon Counting (PC)  \nmode. An uncataloged X-ray source is detected within the BAT error  \ncircle and is potentially the afterglow of GRB 111208A. The refined  \nXRT position is RA, Dec = 290.2251, +40.6766 which is equivalent to:\n\nRA (J2000); 19 20 54.0\nDec(J2000): +40 40 35.8\n\nwith an uncertainty of 4.1 arcsec (radius, 90% confidence). This  \nposition is 39.7 arcsec from the BAT position, within the BAT error  \ncircle. This position may be improved as more data are received. We  \ncannot determine whether the source is fading at the present time.\nThe Swift/UVOT began settled observations of the field of GRB 111208A  \n24.3 ks after the BAT trigger. No optical afterglow consistent with  \nthe XRT position is detected in the initial UVOT exposures.   \nPreliminary 3-sigma upper limits using the UVOT photometric system  \n(Poole et al. 2008, MNRAS, 383, 627) for the initial exposures are:\n\nFilter         T_start(ks)   T_stop(ks)      Exp(s)         Mag\nwhite             24.3          34.9          2100         >22.0\nThe magnitude in the table is not corrected for the Galactic  \nextinction due to the reddening of E(B-V) = 0.12 in the direction of  \nthe burst (Schlegel et al. 1998).  We note that this is a crowded  \nfield and that there is a source a few arcseconds outside the XRT  \nerror circle.  However, this source is clearly visible in archival  \noptical imaging.",
  "circularId": 12631,
  "createdOn": 1323381603000,
  "email": "hoversten@astro.psu.edu",
  "subject": "GRB 111208A: Swift XRT/UVOT observations",
  "submitter": "Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>",
  "eventId": "GRB 111208A"
}