{
  "bibcode": "1999GCN...401....1F",
  "body": "F. Frontera, Istituto TESRE, CNR, Bologna and University of\nFerrara, Italy; M. Capalbi, M.R. Daniele, A. Malizia, M. Perri, BeppoSAX\nSDC, Rome, Italy; E. Montanari, University of Ferrara, Italy; M. R.\nDaniele, A. Paolino, R. Ricci, G. Tarei, A. Tesseri, BeppoSAX SOC,\nRome, Italy; C. Pastor, M. Stornelli, SAX-OCC, Rome, Italy; E. Pian,\nIstituto TESRE, CNR, Bologna, Italy; G. Gandolfi and L. Piro, IAS,\nCNR, Rome, Italy, on behalf of a larger collaboration, report:  \n\"The BeppoSAX Wide Field Camera error box of GRB990806 BeppoSAX MAIL n.\n99/22 and GCN #392) was observed with the BeppoSAX Narrow Field\nInstruments (NFI) starting about 8 hrs after the burst in the period Aug.\n06.9267-08.6563 UT. Preliminary analysis of MECS2+3 data shows a\npreviously unknown X-ray source, 1SAX J0310.6-6806, located at RA =\n03h10m35s, Dec = -68o06'35'' (equinox 2000.0), with an error radius of 1'.\nThis position is very close to  the centroid of the WFC error box. During\nthe observation, the 1.4-10 keV source flux decreases by a factor 4,\nfrom (8.6 +- 2.4)x10E-3 cts/s, corresponding to (5.5 +- 1.5)x10E-13 erg\nsE-1 cmE-2 to (2.3 +- 0.6)x10E-3 cts/s corresponding to\n(1.5 +- 0.6)x10E-13 erg sE-1 cmE-2. For comparison a ROSAT source, 1RXS\nJ031250.0-680915, out of the WFC error box but visible in the same MECS\nimage, does not show any statistically significant variation during the\nentire observation. We conclude that 1SAX J0310.6-6806 is likely the X-ray\nafterglow of GRB990806.\"\n\nThis message can be cited",
  "circularId": 401,
  "createdOn": 934307252000,
  "email": "filippo@tesre.bo.cnr.it",
  "subject": "GRB990806 BeppoSAX follow up",
  "submitter": "Filippo Frontera at ITESRE CNR  <filippo@tesre.bo.cnr.it>",
  "eventId": "GRB 990806"
}