{
  "bibcode": "1999GCN...409....1P",
  "body": "L. Piro (IAS/CNR), M. Capalbi, R. Ricci (BeppoSAX SDC), M. Dadina\n(IAS/CNR & BeppoSAX SOC), L. Di Ciolo (BeppoSAX SOC), C. De Libero\n(BeppoSAX OCC), R.C. Butler (ASI)  report:\n \nA BeppoSAX follow-up observation of GRB990907 (GCN 405)\nstarted on Sept. 8, 4:32 U.T.  Due to technical problems the observation\nlasted 20 minutes only, with an exposure time of 1070 s. in the\nMECS(1.6-10 keV).  A previously unknown X-ray source 1SAXJ0731.2-6928\nis detected within the WFC error box with  a MECS count rate of\n(2.0+/-0.6)x10^-2 cts/s.\nThe position (equinox 2000) is R.A.=7h 31m 12 s Decl=-69 28' 10\", i.e.\n4' away from the center of the WFC position (GCN405).\nDue to the vicinity of the source to the support grid of the detector\nwe estimate an error of 3' in radius and a flux (2-10 keV) between 1 and\n2 x 10^-12 erg/cm^2/s.  The probability that a serendipitous source\nwith similar strength is found in the WFC error circle is about 3x10^-3.\nWe conclude that 1SAXJ0731.2-6928 is likely the X-ray afterglow of GRB990907.",
  "circularId": 409,
  "createdOn": 937417687000,
  "email": "piro@alpha1.ias.rm.cnr.it",
  "subject": "GRB990907: BeppoSAX follow up and X-ray afterglow",
  "submitter": "Luigi Piro at IAS/CNR Frascati  <piro@alpha1.ias.rm.cnr.it>",
  "eventId": "GRB 990907"
}