{
  "bibcode": "2011GCN.12103....1M",
  "body": "A. Melandri (INAF-OAB), S. D. Barthelmy (GSFC), M. M. Chester (PSU),\nN. P. M. Kuin (UCL-MSSL), V. Mangano (INAF-IASFPA),\nC. B. Markwardt (NASA/GSFC) and B. Sbarufatti (INAF-OAB/IASFPA) report\non behalf of the Swift Team:\n\nAt 08:38:38 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated SGR 1E 1841-045 / Kes 73  (trigger=456505).  Swift slewed immediately\nto the location.  The BAT on-board calculated location is \nRA, Dec 280.314, -4.948, which is \n   RA(J2000)  = 18h 41m 15s\n   Dec(J2000) = -04d 56' 53\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve shows a single spike\nwith a duration of less than 0.064 sec.  The peak count rate\nwas ~10,300 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 08:39:49.8 UT, 71.1 seconds after\nthe BAT trigger. Using promptly downlinked data we find an X-ray source\nlocated at RA, Dec 280.33084, -4.93597 which is equivalent to:\n   RA(J2000)  = 18h 41m 19.40s\n   Dec(J2000) = -04d 56' 09.5\"\nwith an uncertainty of 3.8 arcseconds (radius, 90% containment). This\nposition may be improved as more data are received; the latest position\nis available at http://www.swift.ac.uk/sper. This position is 1.8\narcseconds from that of a known X-ray source: 2XMM J184119.2-045611 in\nthe XMM-NEWTON XMMSSC catalogue. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density in excess of the Galactic value (1.57 x\n10^22 cm^-2, Kalberla et al. 2005), with an excess column of 1\n(+1.17/-0.92) x 10^22 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 74 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. No correction has been made for the large, but\nuncertain extinction expected. \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": 12103,
  "createdOn": 1309597269000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "SGR 1E 1841-045: Swift detection of a soft gamma repeater burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>"
}