{
  "bibcode": "2010GCN.11370....1D",
  "body": "M. De Pasquale (UCL-MSSL), A. P. Beardmore (U Leicester),\nP. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),\nS. T. Holland (CRESST/USRA/GSFC), P. T. O'Brien (U Leicester),\nC. Pagani (U Leicester), C. J. Saxton (UCL-MSSL),\nB. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU),\nM. Stamatikos (OSU/NASA/GSFC) and R. L. C. Starling (U Leicester)\nreport on behalf of the Swift Team:\n\nAt 11:39:29.82 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 101024A (trigger=437016).  Swift slewed immediately to the burst.\nThe BAT on-board calculated location is\nRA, Dec 66.475, -77.248 which is\n    RA(J2000) = 04h 25m 54s\n    Dec(J2000) = -77d 14' 50\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including\nsystematic uncertainty). The lightcurve shows 4 distinct peaks, with the\nbrightest peaking at T0+10s. Duration was about 23s.\n\nThe XRT began observing the field at 11:40:46.8 UT, 77.0 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source with an enhanced position: RA, Dec 66.5064, -77.2648 which\nis equivalent to:\n    RA(J2000)  = 04h 26m 1.54s\n    Dec(J2000) = -77d 15' 53.2\"\nwith an uncertainty of 2.1 arcseconds (radius, 90% containment). This\nlocation is 66 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 (6.52 x\n10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.2\n(+1.39/-1.27) x 10^21 cm^-2 (90% confidence).\n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 81 seconds after the BAT trigger. There is a candidate afterglow in\nthe rapidly available 2.7'x2.7' sub-image at\n   RA(J2000)  =\t04:26:01.73 =  66.50719\n   DEC(J2000) = -77:15:55.9  = -77.26552\nwith a 90%-confidence error radius of about 0.64 arc sec. This position is 2.1\narc sec. from the center of the XRT error circle. The estimated magnitude is\n19.38 with a 1-sigma error of about  0.15. No correction has been made for the\nexpected extinction corresponding to E(B-V) of 0.09.\n\nBurst Advocate for this burst is M. De Pasquale (mdp@mssl.ucl.ac.uk).\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": 11370,
  "createdOn": 1287921805000,
  "email": "pae9@star.le.ac.uk",
  "subject": "GRB 101024A: Swift detection of a burst with an optical afterglow",
  "submitter": "Phil Evans at U of Leicester  <pae9@star.le.ac.uk>",
  "eventId": "GRB 101024A"
}