{
  "bibcode": "2015GCN.18104....1S",
  "body": "B. Sbarufatti (INAF-OAB/PSU), S. D. Barthelmy (GSFC),\nJ. R. Cummings (NASA/UMBC), L. M. Z. Hagen (PSU),\nN. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC),\nD. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the\nSwift Team:\n\nAt 22:41:48 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 150801B (trigger=650977).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 82.959, -5.387 which is \n   RA(J2000) = 05h 31m 50s\n   Dec(J2000) = -05d 23' 14\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows several overlapping peaks\nwith a total duration of about 20 sec.  The peak count rate\nwas ~2600 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 22:43:07.3 UT, 78.8 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source with an enhanced position: RA, Dec 82.9666, -5.3883 which\nis equivalent to:\n   RA(J2000)  = 05h 31m 51.99s\n   Dec(J2000) = -05d 23' 18.0\"\nwith an uncertainty of 2.3 arcseconds (radius, 90% containment). This\nlocation is 27 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 does not constrain the column density. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 83 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\n0.24. \n\nWe note that this event is in the vicinity of the Orion Nebula. \nHowever, it appears in all other respects to be a typical GRB. \n\nBurst Advocate for this burst is B. Sbarufatti (boris.sbarufatti AT brera.inaf.it). \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": 18104,
  "createdOn": 1438469936000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 150801B: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 150801B"
}