{
  "bibcode": "2009GCN..9101....1Z",
  "body": "H. Ziaeepour (UCL-MSSL), S. D. Barthelmy (GSFC),\nW. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),\nD. N. Burrows (PSU), P. A. Evans (U Leicester),\nN. Gehrels (NASA/GSFC), O. Godet (U Leicester),\nC. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC),\nJ. A. Kennea (PSU), N. P. M. Kuin (MSSL), J. Mao (INAF-OAB),\nP. T. O'Brien (U Leicester), S. R. Oates (UCL-MSSL),\nJ. P. Osborne (U Leicester), K. L. Page (U Leicester),\nD. M. Palmer (LANL), P. Romano (INAF-IASFPA),\nB. A. Rowlinson (U Leicester), B. Sbarufatti (INAF-IASFPA),\nP. Schady (MSSL-UCL) and G. Stratta (ASDC) report on behalf of the\nSwift Team:\n\nAt 10:28:25 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 090407 (trigger=348650).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 68.959, -12.665 which is \n   RA(J2000) = 04h 35m 50s\n   Dec(J2000) = -12d 39' 53\"\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, including a small\npeak at T+135 sec, during the XRT/UVOT observations.  The peak count rate\nwas ~2390 counts/sec (15-350 keV), at ~1 sec after the trigger. \n\nThe XRT began observing the field at 10:29:58.7 UT, 93.0 seconds after\nthe BAT trigger. Using promptly downlinked data we find a fading,\nuncatalogued X-ray source located at RA, Dec 68.98074, -12.67921 which\nis equivalent to:\n   RA(J2000)  = 04h 35m 55.38s\n   Dec(J2000) = -12d 40' 45.2\"\nwith an uncertainty of 3.8 arcseconds (radius, 90% containment). This\nlocation is 91 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 (3.68e+20\ncm^-2, Kalberla et al. 2005), with an excess column of 2.5\n(+1.79/-1.62) x 10^21 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White \nfilter  starting 97 seconds after the BAT trigger. No credible \nafterglow candidate has  been found in the initial data products. The\n2.7'x2.7' sub-image covers 25% of the BAT error circle and 0% of the\nXRT error circle. The typical 3-sigma upper limit has been about 19.6\nmag. The 8'x8'  region for the list of sources generated on-board\ncovers 100% of the  BAT and XRT error circles. The list of sources is\ntypically complete to about  18 mag. No correction has been made for\nthe expected extinction  corresponding to E(B-V) of 0.07. \n\nBurst Advocate for this burst is H. Ziaeepour (hz AT 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": 9101,
  "createdOn": 1239101288000,
  "email": "dxb15@psu.edu",
  "subject": "GRB 090407: Swift detection of a burst",
  "submitter": "David Burrows at PSU/Swift  <dxb15@psu.edu>",
  "eventId": "GRB 090407"
}