{
  "bibcode": "2009GCN..9668....1V",
  "body": "L. Vetere (PSU), A. P. Beardmore (U Leicester),\nN. Gehrels (NASA/GSFC), C. Gronwall (PSU),\nS. T. Holland (CRESST/USRA/GSFC), F. E. Marshall (NASA/GSFC),\nP. T. O'Brien (U Leicester), J. P. Osborne (U Leicester),\nC. Pagani (PSU), J. L. Racusin (PSU), B. Sbarufatti (INAF-IASFPA),\nM. H. Siegel (PSU), M. Stamatikos (NASA/ORAU) and M. A. Stark (PSU)\nreport on behalf of the Swift Team:\n\nAt 21:03:14 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 090715B (trigger=357512).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 251.344, +44.827 which is \n   RA(J2000) = 16h 45m 23s\n   Dec(J2000) = +44d 49' 36\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a multi-peaked \nstructure with a duration of about 100 sec.  The peak count rate\nwas ~8000 counts/sec (15-350 keV), at ~6 sec after the trigger. \n\nThe XRT began observing the field at 21:04:00.9 UT, 46.2 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 251.3405, +44.8377 which is equivalent to:\n   RA(J2000)  = 16h 45m 21.71s\n   Dec(J2000) = +44d 50' 15.7\"\nwith an uncertainty of 4.9 arcseconds (radius, 90% containment). This\nlocation is 39 arcseconds from the BAT onboard position, within the BAT\nerror circle. No event data are yet available to determine the column\ndensity using X-ray spectroscopy. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 53 seconds after the BAT trigger. There is a weak source in\n2.7'x2.7' sub-image near the edge of the XRT error circle at the position of\n  RA(J2000) = 16:45:21.62\n  Dec(J2000) = +44:50:21.3\nThe estimated white magnitude 20.5 with an estimated error of 0.5 mag. \nNo correction has been made for the expected extinction corresponding \nto E(B-V) of 0.01. \n\nSwift autonomous slewing to new GRBs was enabled just prior to this\nburst.  It was disabled previously due to an anomaly with the\non-board solid state recorder.  That problem is now resolved. \n\nBurst Advocate for this burst is L. Vetere (vetere 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": 9668,
  "createdOn": 1247693671000,
  "email": "vetere@astro.psu.edu",
  "subject": "GRB 090715B: Swift detection of a burst with a possible optical counterpart",
  "submitter": "Loredana Vetere at PSU  <vetere@astro.psu.edu>",
  "eventId": "GRB 090715B"
}