{
  "bibcode": "2005GCN..3466....1B",
  "body": "D. Band (GSFC/UMBC), J. Cummings (GSFC/NRC), M. Perri\n(ASDC), S. Holland (GSFC/USRA), D. N. Burrows (PSU), N.\nGehrels (GSFC), J. E. Hill, J. A. Kennea, S. Hunsberger\n(PSU), C. Markwardt (GSFC/UMD), D. Palmer (LANL) on behalf\nof the Swift Team.\n\nAt 00:02:53 UT, the BAT instrument on the Swift spacecraft\ntriggered (trigger=130088) and located GRB 050525.  The BAT\non-board calculated location is RA,Dec 278.144 , +26.340\n(18h 32m 35s +26d 20' 23\") (J2000) with an uncertainty of 3\narcmin (radius, 3-sigma, including systematic uncertainty).\nThis is a very bright burst, yielding about 1500 counts\nover background in 64 ms (preliminary) in the 25-100 keV\nrange in the BAT instrument.  This would correspond to a\nrate of 10 counts/sec/cm2 in that 64 ms interval, but the\npeak rate in a later interval may be greater.  Although\nlight curves are not yet available, the BAT rate trigger\ncontinued to evaluate different timescales while data from\nthe first 64 ms was being imaged.  The merit parameters\nindicate that the highest significance rate trigger is for\na 1 second interval, consistent with a short burst.  More\ndetails will be available after the full data pass.\n\nThe XRT was pointed promptly at the burst and took an image\nat 00:04:58 UT (125 s after the BAT burst trigger).  The\nXRT found a bright X-ray source near the center of the\nfield of view, with position RA(J2000) = 18h 32m 32.3s\nDec(J2000) = +26d 20' 17.5\"  We estimate an uncertainty of\nabout 6 arcseconds radius (90% containment).  This position\nis 31 arcseconds from the BAT position and 8 arcseconds\nfrom the ROTSE position (Rykoff et al, GCN 2465).\n\nWe caution that the XRT is in the middle of engineering\ntests and is in an unusual mode.  While the X-ray afterglow\nlooks unusually strong, there are also indications that the\nXRT instrument configuration is abnormal due to the tests\nbeing performed.\n\nThe XRT position is outside of the UVOT-TDRSS image.\nAnalysis of the UVOT data will take place after the next\nfull data pass.\n\nThis is a bright burst that appears to be in the short\ncategory; the Sun and moon angles are conducive for optical\nobservations. Followup observations are strongly\nencouraged.",
  "circularId": 3466,
  "createdOn": 1116984974000,
  "email": "dband@lheapop.gsfc.nasa.gov",
  "subject": "GRB 050525: Swift Detection of a Bright, Possibly Short Burst",
  "submitter": "David L. Band at NASA/GSFC  <dband@lheapop.gsfc.nasa.gov>",
  "eventId": "GRB 050525"
}