{
  "bibcode": "2016GCN.19204....1B",
  "body": "S. D. Barthelmy (GSFC), V. D'Elia (ASDC), N. Gehrels (NASA/GSFC),\nL. Izzo (URoma1), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),\nD. M. Palmer (LANL), M. H. Siegel (PSU) and T. N. Ukwatta (LANL)\nreport on behalf of the Swift Team:\n\nAt 22:41:24 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated a burst from an apparent new Soft Gamma Repeater,\nSGR 0755-2933 (trigger=679432).  Swift slewed immediately to the source. \nThe BAT on-board calculated location is \nRA, Dec 118.884, -29.552 which is \n   RA(J2000)  =  07h 55m 32s\n   Dec(J2000) = -29d 33' 08\"\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 128 msec.  The peak count rate\nwas ~1900 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 22:42:39.1 UT, 74.9 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source with an enhanced position: RA, Dec 118.9270, -29.5637\nwhich is equivalent to:\n   RA(J2000)  = 07h 55m 42.48s\n   Dec(J2000) = -29d 33' 49.2\"\nwith an uncertainty of 2.0 arcseconds (radius, 90% containment). This\nlocation is 141 arcseconds from the BAT onboard position, within the\nBAT error circle. This position may be improved as more data are\nreceived; the latest position is available at\nhttp://www.swift.ac.uk/sper. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density in excess of the Galactic value (6.09 x\n10^21 cm^-2, Willingale et al. 2013), with an excess column of 5.2\n(+3.68/-3.17) x 10^21 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 250 seconds with the U filter\nstarting  135 seconds after the BAT trigger. No credible afterglow\ncandidate has been  found in the initial data products. The 2.7'x2.7'\ncovers none of the XRT error circle. The 8'x8' region for the list of\nsources generated on-board covers 100% of the XRT  error circle. The\nlist of sources is typically complete to about 18.0 mag. No correction\nhas been made for the  large, but uncertain extinction expected. \n\nGiven that this was a short event (<128 msec) and spectrally soft (in BAT) \nand that it is on the Galactic Plane (lat = -0.6 deg), it is likely a \nnew SGR, tentatively named SGR 0755-2933.  The XRT source has a count rate of \nseveral counts per second and is variable but not fading.",
  "circularId": 19204,
  "createdOn": 1458170019000,
  "email": "scott@milkyway.gsfc.nasa.gov",
  "subject": "Swift detection of a likely new SGR: SGR 0755-2933",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>"
}