{
  "bibcode": "2017GCN.20944....1D",
  "body": "P. D'Avanzo (INAF-OAB), S. D. Barthelmy (GSFC),\nA. Cholden-Brown (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),\nF. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),\nB. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf\nof the Swift Team:\n\nAt 22:29:51 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 170330A (trigger=744773).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 283.326, -13.437, which is \n   RA(J2000)  =  18h 53m 18s\n   Dec(J2000) = -13d 26' 12\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows a single peak\nwith a duration of about 10 sec.  The peak count rate\nwas ~1000 counts/sec (15-350 keV), at ~3 sec after the trigger. \n\nThe XRT began observing the field at 22:31:29.6 UT, 98.4 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 283.3323, -13.4301 which is equivalent to:\n   RA(J2000)  = +18h 53m 19.75s\n   Dec(J2000) = -13d 25' 48.4\"\nwith an uncertainty of 5.9 arcseconds (radius, 90% containment). This\nlocation is 33 arcseconds from the BAT onboard position, within the BAT\nerror circle. No event data are yet available to determine the column\ndensity using X-ray spectroscopy. \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 108 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. Because of the density of catalogued stars, further\nanalysis is required to report an upper limit for any afterglow in the\nsub-image. The 8'x8' region for the list of sources generated on-board covers\n100% of the XRT error circle. Because of the density of catalogued stars,\nfurther analysis is required to report an upper limit for any afterglow in the\nregion. No correction has been made for the expected extinction corresponding\nto E(B-V) of 0.45. \n\nBurst Advocate for this burst is P. D'Avanzo (paolo.davanzo 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": 20944,
  "createdOn": 1490913827000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "GRB 170330A: Swift detection of a burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 170330A"
}