{
  "bibcode": "2011GCN.11753....1S",
  "body": "T. Sakamoto (NASA/UMBC), S. D. Barthelmy (GSFC),\nW. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),\nP. A. Evans (U Leicester), J. M. Gelbord (PSU),\nC. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC),\nE. A. Hoversten (PSU), J. A. Kennea (PSU),\nH. A. Krimm (CRESST/GSFC/USRA), F. E. Marshall (NASA/GSFC),\nD. M. Palmer (LANL), E. Sonbas (GSFC/USRA/Adiyaman Univ.),\nM. Stamatikos (OSU/NASA/GSFC) and C. A. Swenson (PSU) report on behalf\nof the Swift Team:\n\nAt 20:56:59 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 110223A (trigger=446674).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 345.599, +87.567 which is \n   RA(J2000)  =  23h 02m 24s\n   Dec(J2000) = +87d 34' 03\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows a single peak\nwith a duration of about 5 sec.  The peak count rate\nwas ~1600 counts/sec (15-350 keV), at ~1 sec after the trigger. \n\nThe XRT began observing the field at 20:58:27.8 UT, 88.6 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nuncatalogued X-ray source located at RA, Dec 345.85923, 87.55851 which\nis equivalent to:\n   RA(J2000)  = 23h 03m 26.22s\n   Dec(J2000) = +87d 33' 30.6\"\nwith an uncertainty of 3.7 arcseconds (radius, 90% containment). This\nlocation is 50 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 (5.61 x\n10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.5\n(+1.82/-1.63) x 10^21 cm^-2 (90% confidence). \n\nThe initial flux in the 2.5 s image was 8.97e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 97 seconds after the BAT trigger. No credible afterglow candidate has\nbeen found in the initial data products. The 2.7'x2.7' sub-image covers 100% of\nthe XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. \nThe 8'x8' region for the list of sources generated on-board covers 100% of the\nXRT error circle. The list of sources is typically complete to about 18 mag. No\ncorrection has been made for the expected extinction corresponding to E(B-V) of\n0.34. \n\nBurst Advocate for this burst is T. Sakamoto (Taka.Sakamoto AT 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": 11753,
  "createdOn": 1298495378000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 110223A: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 110223A"
}