{
  "bibcode": "2015GCN.18264....1P",
  "body": "C. Pagani (U Leicester), A. P. Beardmore (U Leicester),\nA. A. Breeveld (UCL-MSSL), K. L. Page (U Leicester),\nP. Romano (INAF-IASFPA) and T. N. Ukwatta (LANL) report on behalf of\nthe Swift Team:\n\nAt 09:04:48 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 150910A (trigger=655097). Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 5.675, +33.499 which is \n   RA(J2000) = 00h 22m 42s\n   Dec(J2000) = +33d 29' 55\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty). As is typical for image triggers, the real-time\nlight curve does not show anything significant. \n\nThe XRT began observing the field at 09:07:14.1 UT, 145.3 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 5.6669, 33.4717 which is equivalent to:\n   RA(J2000)  = +00h 22m 40.06s\n   Dec(J2000) = +33d 28' 18.1\"\nwith an uncertainty of 5.1 arcseconds (radius, 90% containment). This\nlocation is 101 arcseconds from the BAT onboard position, within the\nBAT error circle. No event data are yet available to determine the\ncolumn density using X-ray spectroscopy. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 153 seconds after the BAT trigger. There is a candidate afterglow in\nthe rapidly available 2.7'x2.7' sub-image at\n  RA(J2000)  =\t00:22:40.14 =\t5.66723\n  DEC(J2000) = +33:28:21.9  =  33.47275\nwith a 90%-confidence error radius of about 0.71 arc sec. This position is 3.9\narc sec. from the center of the XRT error circle. The estimated magnitude is\n20.27 with a 1-sigma error of about  0.18. No correction has been made for the\nexpected extinction corresponding to E(B-V) of 0.05. \n\nBurst Advocate for this burst is C. Pagani (cp232 AT star.le.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": 18264,
  "createdOn": 1441877213000,
  "email": "klp5@leicester.ac.uk",
  "subject": "GRB 150910A: Swift detection of a burst with an optical afterglow",
  "submitter": "Kim Page at U.of Leicester  <klp5@leicester.ac.uk>",
  "eventId": "GRB 150910A"
}