{
  "bibcode": "2015GCN.17592....1S",
  "body": "M. H. Siegel (PSU), S. D. Barthelmy (GSFC), M. M. Chester (PSU),\nN. Gehrels (NASA/GSFC), H. A. Krimm (CRESST/GSFC/USRA),\nA. Y. Lien (GSFC/UMBC), D. Malesani (DARK/NBI),\nC. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),\nD. M. Palmer (LANL) and B. Sbarufatti (INAF-OAB/PSU) report on behalf\nof the Swift Team:\n\nAt 04:22:42 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 150317A (trigger=635148).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 138.935, +55.452, which is \n   RA(J2000)  =  09h 15m 45s\n   Dec(J2000) = +55d 27' 08\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows three spikes \nspaced about 10 seconds apart, with a total duration of about 35 sec. \nThe peak count rate was ~1700 counts/sec (15-350 keV), at ~0 sec \nafter the trigger. \n\nThe XRT began observing the field at 04:23:46.5 UT, 64.6 seconds after\nthe BAT trigger. \nIn a 25 s SPER image XRT detects 10 photons at \nRA, DEC 138.9832, 55.4681 which is    \n   RA(J2000)  =  09h 15m 55.98s\n   Dec(J2000) = +55:28:05.23\nwith an uncertainty of 8.6 arcsec (radius, 90% containment). This position is 1.9 \narcmin away from the BAT onboard position, within the BAT error circle. \n\nWe notice the presence of a bright star (R~11) at 11 arcseconds from the XRT \nposition. At this time we cannot exclude that emission from the star \nmay be affecting the XRT data. \n\nUVOT took a finding chart exposure of 250 seconds with the U filter\nstarting 126 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 none 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 M. H. Siegel (siegel AT swift.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": 17592,
  "createdOn": 1426569431000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 150317A: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 150317A"
}