{
  "bibcode": "2010GCN.11386....1M",
  "body": "A. Melandri (INAF-OAB), S. D. Barthelmy (GSFC), M. M. Chester (PSU),\nV. D'Elia (ASDC), J. M. Gelbord (PSU), C. Guidorzi (U Ferrara),\nS. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),\nJ. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),\nR. Margutti (INAF-OAB), F. E. Marshall (NASA/GSFC),\nK. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and\nE. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:\n\nAt 15:56:29 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 101030A (trigger=437408).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 166.390, -16.387 which is \n   RA(J2000)  =  11h 05m 34s\n   Dec(J2000) = -16d 23' 11\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows that the burst began\nwith a bright peak starting at around -70 sec from the trigger, \nfollowed by a second episode starting at T-10 sec and consisting of two\noverlapping peaks with a duration of about 80 sec.  We note that the \nfirst peak occurred during a pre-planned slew, so the BAT could not \ntrigger on it; it is also possible that BAT missed emission from the \nburst before T-100 sec.  The peak count rate was ~2000 counts/sec \n(15-350 keV), at ~0 sec after the trigger. \n\n\nThe XRT began observing the field at 15:57:35.6 UT, 65.7 seconds after\nthe BAT trigger. Using promptly downlinked data we find a bright,\nfading, uncatalogued X-ray source with an enhanced position: RA, Dec\n166.3825, -16.3782 which is equivalent to:\n   RA(J2000)  = 11h 05m 31.80s\n   Dec(J2000) = -16d 22' 41.5\"\nwith an uncertainty of 2.5 arcseconds (radius, 90% containment). This\nlocation is 40 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 4.24\nx 10^20 cm^-2 (Kalberla et al. 2005). \n\nThe initial flux in the 2.5 s image was 2.81e-09 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 73 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\n0.04. \n\nBurst Advocate for this burst is A. Melandri (andrea.melandri 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": 11386,
  "createdOn": 1288455235000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 101030A: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 101030A"
}