{
  "bibcode": "2012GCN.13774....1C",
  "body": "J. R. Cummings (NASA/UMBC), C. Gronwall (PSU), D. Grupe (PSU),\nH. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC),\nD. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and\nM. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team:\n\nAt 09:16:06 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated an unidentified source near the Galactic center (trigger=533836). \nSwift slewed immediately to the source location. \nThe BAT on-board calculated location is \nRA, Dec 266.322, -26.400 which is \n   RA(J2000) = 17h 45m 17s\n   Dec(J2000) = -26d 23' 58\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  This is a 16 minute long image trigger,\nso there is no immediately available lightcurve data.  The on-board detection\nsignificance is 8.5 sigma. \n\nThe XRT began observing the field at 09:36:59.0 UT, 1252.7 seconds\nafter the BAT trigger. XRT found a possible X-ray source\nlocated at RA, Dec 266.2960, -26.4025 which is equivalent to:\n   RA(J2000)  = +17h 45m 11.04s\n   Dec(J2000) = -26d 24' 09.0\"\nwith an uncertainty of 5.8 arcseconds (radius, 90% containment). This\nlocation is 84 arcseconds from the BAT onboard position, within the BAT\nerror circle. We are waiting for the full dataset to download in order \nto confirm the existence of the source. \n\nThe initial flux in the 2.5 s image was 8.01e-10 erg cm^-2 s^-1 (0.2-10\nkeV). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 1259 seconds after the BAT trigger. No credible afterglow candidate\nhas been found in the initial data products. The 2.7'x2.7' sub-image 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\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 large, but uncertain extinction\nexpected. \n\nDue to its position 152 arcminutes from the Galactic center,\nand its duration (discovered in a 16-minute long imag trigger),\nwe believe that this is a previously-uncatalogued Galactic\ntransient.  A final determination of the status of this source\nwill require the downlinked data from the ground station. \n\nA 'Swift J' source name will be assigned based on the final \nX-ray position.",
  "circularId": 13774,
  "createdOn": 1347789916000,
  "email": "palmer@lanl.gov",
  "subject": "Swift Trigger 533836 is a new Galactic transient",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>"
}