TITLE: GCN GRB OBSERVATION REPORT NUMBER: 553 SUBJECT: GRB000210 X-ray afterglow DATE: 00/02/14 16:39:43 GMT FROM: Angelo Antonelli at Obs. Astro. di Roma E. Costa, Istituto di Astrofisica Spaziale, CNR, Rome, L.A. Antonelli, Osservatorio Astronomico di Roma, Rome, J. in 't Zand, Space Research Organization Netherlands, Utrecht; M. Stornelli, D. Ricci, M.R. Daniele, M. Capalbi, BeppoSAX Science Operations Center, Telespazio, Rome; M. Feroci, G. Gandolfi, Istituto di Astrofisica Spaziale, CNR, Rome, E. Pian, ITESRE, CNR, Bologna, report: "GRB 000210 was observed with the Narrow Field Instruments (NFI) on board BeppoSAX from Feb. 10.66 UT to 11.98 UT (starting 7.2 hrs after the burst trigger time). In the combined image of both Medium-Energy Concentrator Spectrometers, taken over the whole observation, a point source, showing an unambiguous fading behaviour, is detected with a position of R.A. = 01h59m15.9s, Decl. = -40d39'29" (Eq. 2000.0) and an error circle of 50''. This is consistent with the position given by Chandra in an observation performed during the central part of BeppoSAX observation (GCN #548) and with the position of the optical object reported in GCN #545. In the first 30,000 s of the observation the object flux (2-10 keV) is about 4.5E-13 erg/cmE2/s. In the last 40,000 s of the observation the source has faded of about a factor three but a fainter soft source, located at about 2 arcmin NE from the X-ray afterglow, contributes a flux not negligible. Therefore an evaluation of the flux and the decay law needs a more refined analysis." This message is citable.