{
  "bibcode": "2009GCN..9185....1U",
  "body": "T. N. Ukwatta (GSFC/GWU), S. D. Barthelmy (GSFC),\nN. Gehrels (NASA/GSFC), J. A. Kennea (PSU), D. M. Palmer (LANL),\nM. Perri (ASDC), G. Stratta (ASDC) and L. Vetere (PSU) report on\nbehalf of the Swift Team:\n\nAt 03:35:16 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 090422 (trigger=349931).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 294.756, +40.384 which is \n   RA(J2000) = 19h 39m 01s\n   Dec(J2000) = +40d 23' 03\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows two spikes\nwith a total duration of about 10 sec.  The peak count rate\nwas ~3500 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 03:36:20.6 UT, 64.0 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nfading, uncatalogued X-ray source located at RA, Dec 294.74931,\n40.38530 which is equivalent to:\n   RA(J2000)  = 19h 38m 59.83s\n   Dec(J2000) = +40d 23' 07.1\"\nwith an uncertainty of 3.9 arcseconds (radius, 90% containment). This\nlocation is 18 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\n1.65e+21 cm^-2 (Kalberla et al. 2005). \n\nThe initial flux in the 2.5 s image was 5.51e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 74 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 coverage of the XRT error circle by the 8'x8' region for the list of\nsources generated on-board is uncertain because the large number of sources\nfilled the available telemetry. No correction has been made for the expected\nextinction corresponding to E(B-V) of 0.20. \n\nBurst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). \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": 9185,
  "createdOn": 1240372317000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 090422: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 090422"
}