{
  "bibcode": "2007GCN..7147....1S",
  "body": "T. Sakamoto (NASA/UMBC), W. H. Baumgartner (GSFC/UMBC),\nA. P. Beardmore (U Leicester), M. M. Chester (PSU),\nS. D. Hunsberger (PSU), K. L. Page (U Leicester),\nJ. L. Racusin (PSU), P. Romano (Univ. Bicocca & INAF-OAB),\nG. Sato (GSFC/ISAS), B. Sbarufatti (INAF-IASFPA),\nM. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester),\nE. Troja (INAF-IASFPA) and D. E. Vanden Berk (PSU) report on behalf\nof the Swift Team:\n\nAt 20:13:47 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 071227 (trigger=299787).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 58.120, -55.953 which is \n   RA(J2000) = 03h 52m 29s\n   Dec(J2000) = -55d 57' 08\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed at least three \nspikes with a duration of about 5 sec.  The peak count rate\nwas ~4500 counts/sec (15-350 keV), at ~0.5 sec after the trigger. \n\nThe XRT began observing the field at 20:15:06 UT, 79 seconds after the\nBAT trigger. From prompt downlinked data, XRT found a  variable, uncatalogued \nX-ray source located at RA, Dec 58.1316, -55.9833 which is\n   RA(J2000)  =  03h 52h 31.58s\n   Dec(J2000) = -55d 58' 59.9\"\nwith an uncertainty of 3.7 arcseconds (radius, 90% containment). \nThis location is 112 arcseconds from the BAT on-board position,\nwithin the BAT error circle. The initial flux in the 2.5s image\nwas 9.6e-10 erg/cm2/s (0.2-10 keV). \n\nUVOT took a finding chart exposure of 100 seconds with the White\n(160-650 nm) filter starting 86 seconds after the BAT trigger, and a\nsecond finding chart of 400 seconds in V starting 192 seconds after\nthe trigger. No afterglow candidate has been found in the initial\ndata products. The 2.7'x2.7' sub-image covers 100% of the XRT error\ncircle. The 3-sigma upper limit at the XRT position is 19.9 mag in\nWhite, 19.0 in V. The 8'x8' region for the list of sources generated\non-board covers 100% of the XRT error circle. The list of sources is\ntypically complete to about 18 mag. No correction has been made for\nextinction corresponding to E(B-V) = 0.01. \n\nBurst Advocate for this burst is T. Sakamoto (takanori AT milkyway.gsfc.nasa.gov). \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": 7147,
  "createdOn": 1198787800000,
  "email": "takanori@milkyway.gsfc.nasa.gov",
  "subject": "GRB 071227: Swift detection of a burst",
  "submitter": "Takanori Sakamoto at NASA/GSFC  <takanori@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 071227"
}