{
  "bibcode": "2015GCN.17611....1A",
  "body": "A. Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC),\nF. E. Marshall (NASA/GSFC), C. J. Mountford (U Leicester),\nD. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and\nM. H. Siegel (PSU) report on behalf of the Swift Team:\n\nAt 02:49:14 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 150323A (trigger=635887).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 128.191, +45.434 which is \n   RA(J2000) = 08h 32m 46s\n   Dec(J2000) = +45d 26' 03\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a small peak at the\ntime of the trigger, followed by a much larger peak at T+130 s,\nfor a total duration of at least 170 sec.  The peak count rate\nwas ~5600 counts/sec (15-350 keV), at ~130 sec after the trigger. \n\nThe XRT began observing the field at 02:51:41.2 UT, 146.6 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nfading, uncatalogued X-ray source located at RA, Dec 128.17951,\n45.46355 which is equivalent to:\n   RA(J2000)  = 08h 32m 43.08s\n   Dec(J2000) = +45d 27' 48.8\"\nwith an uncertainty of 3.8 arcseconds (radius, 90% containment). This\nlocation is 110 arcseconds from the BAT onboard position, within the\nBAT error circle. This position may be improved as more data are\nreceived; the latest position is available at\nhttp://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 3.05\nx 10^20 cm^-2 (Willingale et al. 2013). \n\nThe initial flux in the 0.1 s image was 3.25e-08 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 156 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\n0.03. \n\nBurst Advocate for this burst is A. Amaral-Rogers (aar14 AT 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": 17611,
  "createdOn": 1427079687000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 150323A: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 150323A"
}