{
  "bibcode": "2002GCN..1442....1R",
  "body": "G. Ricker, J-L Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of\nthe HETE Science Team;\n\nN. Butler, J. Doty, R. Vanderspek, J. Villasenor, G. Crew, G. Monnelly,\nT. Cline, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin,\nJ. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE\nOperations and HETE Optical-SXC Teams;\n\nY. Shirasaki, C. Graziani, M. Matsuoka, T. Tamagawa, K. Torii,\nT. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, and\nT. Donaghy, on behalf of the HETE WXM Team;\n\nM. Boer, J-F Olive, J-P Dezalay, and K. Hurley on behalf of the HETE\nFREGATE Team;\n\nwrite:\n\n\nAt 11:25:49.32 UTC (41149.32 s UT) on 25 June 2002, the HETE FREGATE\ninstrument detected event H2081.  This event, which triggered FREGATE\nin Band C (30-400 keV), was very hard:  the event is strongly evident\n(SNR ~ 12) in FREGATE Band C and is evident in FREGATE Band B (6-80\nkeV), but is barely visible, if at all, in FREGATE Band A (6-40 keV)\nand in the WXM 2-25 keV energy band.\n\nA second event occurred 86 sec later.  This event was much softer: it\nis barely visible in FREGATE Band C, but is discernible in FREGATE\nbands A and B.  This second event is also strongly evident in the WXM\n2-25 keV energy band (SNR ~ 8).  Triggers on the WXM data are currently\noff in order to avoid inundating the astronomical community with XRB\ntriggers, and therefore no WXM flight location was calculated for this\nevent.\n\nThe probability of the HETE FREGATE and WXM instruments detecting two\nseparate GRBs within 100 sec is very small.  We therefore interpret\nthe two events as part of a single, long GRB, consisting of two main\npeaks and having a duration > 125 sec.\n\nNo real-time spacecraft aspect was available because of the full moon\n(99% illumination).  Ground analysis produced a location, using the\nspacecraft aspect at the time of trigger H2081 (corresponding to the\nbeginning of the first peak), that was reported in a GCN Position\nNotice at 14:19:24 UT, 173 min after the burst.  Further ground\nanalysis revealed that the spacecraft had drifted by an unusually large\namount (~10 arcminutes) during the burst.  Therefore a refined\nlocation, using the spacecraft aspect at the time of the second peak,\nwhich could be localized using WXM data, was reported in a second GCN\nPosition Notice at 15:16:17 UT, 230 min after the burst.  The refined\nlocation can be expressed as a 90% confidence rectangle that is 18\narcminutes by 32 arcminutes.  The center and the corners of the\nrectangle lie at the following J2000 coordinates:\n\nRA = 20h 44m 14s, Dec = +07o 10' 12\" (center)\nRA = 20h 43m 09s, Dec = +07o 18' 32\" (corner)\nRA = 20h 44m 08s, Dec = +07o 28' 08\" (corner)\nRA = 20h 45m 20s, Dec = +07o 01' 52\" (corner)\nRA = 20h 44m 21s, Dec = +06o 52' 16\" (corner).\n\n\nThe first peak of GRB020625 had a peak flux >6 Crab and a duration of\n~20 sec in  FREGATE Band C (30-400 keV), during which a total of 1200\nnet counts were detected.  The second peak had a peak flux ~2.0 x 10^-8\nergs cm-2 s-1 (i.e., ~1 x Crab flux) averaged over 1.2 sec and a\nduration of ~17 sec in FREGATE Band A (6-40 keV).  During this time\ninterval a total of 830 net counts were detected, corresponding to a\nfluence of ~1.5 x 10^-7 ergs cm-2.  In the WXM 2-25 keV band, the\nsecond peak had a duration of 25 seconds.  The WXM localization SNR\nwas ~9.\n\nFurther information (including a light curve) for GRB020625 is provided\nat the following URL:\n\nhttp://space.mit.edu/HETE/Bursts/\n\nThis message is citable.",
  "circularId": 1442,
  "createdOn": 1025042439000,
  "email": "lamb@oddjob.uchicago.edu",
  "subject": "GRB020625 (=H2081): A Long Burst Localized by HETE",
  "submitter": "Don Lamb at U.Chicago  <lamb@oddjob.uchicago.edu>",
  "eventId": "GRB 020625"
}