{
  "bibcode": "2014GCN.17229....1D",
  "body": "P. D'Avanzo (INAF-OAB), A. P. Beardmore (U Leicester),\nM. G. Bernardini (INAF-OAB), J. R. Cummings (NASA/UMBC),\nN. Gehrels (NASA/GSFC), J. A. Kennea (PSU),\nH. A. Krimm (CRESST/GSFC/USRA), A. Y. Lien (GSFC/UMBC),\nA. Melandri (INAF-OAB), C. J. Mountford (U Leicester) and\nJ. L. Racusin (NASA/GSFC) report on behalf of the Swift Team:\n\nAt 23:01:07 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 141225A (trigger=622476).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 138.751, +33.795 which is \n   RA(J2000) = 09h 15m 00s\n   Dec(J2000) = +33d 47' 41\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a single-peaked\nstructure with a duration of about 30 sec.  The peak count rate\nwas ~1600 counts/sec (15-350 keV), at ~6 sec after the trigger. \n\nThe XRT began observing the field at 23:08:10.5 UT, 423.5 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source with an enhanced position: RA, Dec 138.7782, 33.7919 which\nis equivalent to:\n   RA(J2000)  = 09h 15m 06.77s\n   Dec(J2000) = +33d 47' 30.7\"\nwith an uncertainty of 2.1 arcseconds (radius, 90% containment). This\nlocation is 82 arcseconds from the BAT onboard position, within the BAT\nerror circle. This position may be improved as more data are received;\nthe latest position is available at http://www.swift.ac.uk/sper. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density in excess of the Galactic value (1.48 x\n10^20 cm^-2, Willingale et al. 2013), with an excess column of 1.6\n(+1.62/-1.47) x 10^21 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White\nfilter starting 440 seconds after the BAT trigger. No credible\nafterglow candidate has been found in the initial data products.  The\n8'x 8' region for the list of sources generated on-board covers 100% of\nthe XRT error circle. The list of sources is typically complete to\nabout 18 mag. No correction has been made for the expected extinction\ncorresponding to E(B-V) of 0.02. \n\nMerry Christmas from the Swift Team!\n\nBurst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT brera.inaf.it). \nPlease contact the BA by email if you require additional information\nregarding Swift followup of this burst. In extremely urgent cases, after\ntrying the Burst Advocate, you can contact the Swift PI by phone (see\nSwift TOO web site for information: http://www.swift.psu.edu/too.html.)",
  "circularId": 17229,
  "createdOn": 1419550105000,
  "email": "hans.krimm@nasa.gov",
  "subject": "GRB 141225A: Swift detection of a burst",
  "submitter": "Hans Krimm at NASA-GSFC  <hans.krimm@nasa.gov>",
  "eventId": "GRB 141225A"
}