{
  "bibcode": "2010GCN.11261....1S",
  "body": "M. H. Siegel (PSU), S. D. Barthelmy (GSFC), M. M. Chester (PSU),\nP. A. Evans (U Leicester), J. M. Gelbord (PSU), J. A. Kennea (PSU),\nK. L. Page (U Leicester) and R. L. C. Starling (U Leicester) report on\nbehalf of the Swift Team:\n\nSwift began a target of opportunity observation of GRB 100909A\non September  9, 2010 at 12:18 UT, approximately 3.2 hours\nafter the burst was detected by INTEGRAL. Swift data for these\nobservations utilize Target ID 20147. \n\nThe XRT began observing the field at 12:19:37.4 UT, 11.7 ks after the\nINTEGRAL trigger. In 1.8 ks of promptly downlinked data there is a faint source,\ndetected at the 3.2-sigma level at: RA, Dec= 73.94797, +54.65798 which is \nequivalent to:\n\nRA (J2000) : 04h 55m 47.51s\nDec (J2000): +54d 39' 28.7''\n\nwith an estimated uncertainty of 6 arcsec (radius, 90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White\nfilter  starting 11687 seconds after the INTEGRAL trigger. No credible\nafterglow  candidate has been found in the initial data products. The\n2.7'x2.7' sub-image  covers 44% of the INTEGRAL error circle and 100%\nof the XRT error circle. The typical 3-sigma upper limit has  been\nabout 19.6 mag. The coverage of the INTEGRAL and XRT error circles by\nthe 8'x8'  region for the list of sources generated on-board is\nuncertain because the  large number of sources filled the available\ntelemetry. No correction has been  made for the expected extinction\ncorresponding to E(B-V) of 0.51. \n\nBurst Advocate for this burst is M. H. Siegel (siegel AT astro.psu.edu). \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": 11261,
  "createdOn": 1284037496000,
  "email": "siegel@astro.psu.edu",
  "subject": "GRB 100909A: Swift target of opportunity observation",
  "submitter": "Mike Siegel at PSU/Swift MOC  <siegel@astro.psu.edu>",
  "eventId": "GRB 100909A"
}