{
  "bibcode": "2009GCN..9374....1R",
  "body": "B. A. Rowlinson (U Leicester), A. P. Beardmore (U Leicester),\nP. A. Evans (U Leicester), C. Guidorzi (U Ferrara),\nJ. A. Kennea (PSU), P. T. O'Brien (U Leicester),\nK. L. Page (U Leicester), D. M. Palmer (LANL),\nP. Romano (INAF-IASFPA) and T. Sakamoto (NASA/UMBC) report on behalf\nof the Swift Team:\n\nAt 08:27:50 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 090516 (trigger=352190).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 138.271, -11.858 which is \n   RA(J2000) = 09h 13m 05s\n   Dec(J2000) = -11d 51' 27\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a multiple-peaked\nstructure with a duration of at least 150 sec.  The peak count rate\nwas ~1000 counts/sec (15-350 keV), at ~5 sec after the trigger, with \nadditional prominent peaks at T+35, T+90 and T+135. \n\nThe XRT began observing the field at 08:30:37.4 UT, 166.7 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright, fading,\nuncatalogued X-ray source located at RA, Dec 138.26119, -11.85480 which\nis equivalent to:\n   RA(J2000)  = 09h 13m 2.69s\n   Dec(J2000) = -11d 51' 17.3\"\nwith an uncertainty of 4.1 arcseconds (radius, 90% containment). This\nlocation is 36 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 consistent with the Galactic value of\n4.47e+20 cm^-2 (Kalberla et al. 2005). \n\nThe initial flux in the 0.1 s image was 1.96e-08 erg cm^-2 s^-1 (0.2-10\nkeV). \n\n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 176 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\n0.05. \n\n\n\n\nBurst Advocate for this burst is B. A. Rowlinson (bar7 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": 9374,
  "createdOn": 1242463750000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 090516: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 090516"
}