{
  "bibcode": "1999GCN...322....1K",
  "body": "R. M. Kippen (University of Alabama in Huntsville) reports on behalf\nof the BATSE GRB team:\n\nGRB 990510 was detected by BATSE on 1999 May 10.367434 as trigger\nnumber 7560.  The event was strong and consisted of a complex series\nof pulses with two major episodes lasting >100 s, with significant\nspectral evolution.  The T50 and T90 durations are 32.64 (-/+ 0.45) s\nand 67.58 (-/+ 1.86) s, respectively.  The burst's peak flux (50-300\nkeV; integrated over 1.024 s) and fluence (>20 keV) are 8.16 (-/+\n0.08) photons cmE-2 sE-1 and 2.56 (-/+ 0.09) x 10E-5 erg cmE-2,\nrespectively---ranking it in the top 4% (9%) of the BATSE burst flux\n(fluence) distribution.  The average spectral hardness of the burst,\nas estimated by the ratio of 100-300 keV counts to those in the 50-100\nkeV range, is H32 = 0.764 (-/+ 0.008), which is average among BATSE\nbursts of this duration.  The BATSE burst location is consistent with\nthose measured by BeppoSAX (GCN 304,311) and the IPN (BATSE/Ulysses;\nGCN 309), and with the proposed optical transient counterpart (GCN\n310, 313-321).  A location sky-map and lightcurve for this event (and\nother notable bursts) are available at the BATSE Rapid Burst Response\nworld-wide-web site:\n\n          http://www.batse.msfc.nasa.gov/~kippen/batserbr/\n\nThis notice is citeable.\n\n-eof-",
  "circularId": 322,
  "createdOn": 926547044000,
  "email": "marc.kippen@msfc.nasa.gov",
  "subject": "GRB 990510: BATSE Observations",
  "submitter": "R. Marc Kippen at BATSE/UAH/MSFC  <marc.kippen@msfc.nasa.gov>",
  "eventId": "GRB 990510"
}