TITLE:   GCN CIRCULAR
NUMBER:  812
SUBJECT: GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
DATE:    00/09/29 10:20:21 GMT
FROM:    Luigi Piro at IAS/CNR Frascati  <piro@ias.rm.cnr.it>

L. Piro (BeppoSAX Mission Scientist) on behalf of a large collaboration
reports:


A BeppoSAX TOO observation of GB000926 has started on Sept. 28.979, i.e.
about 2 days after the GRB. Preliminary analysis of the first three orbits
shows a relatively bright (flux about 0.5 10**-12 erg/cm2/s) unknown
source in the MECS(1.6-10 keV) image.

The position is

RA(2000)=17h 04m 07s Decl.(2000)= +51 47' 42"

which is 0.7' from the optical counterpart (Gorosabel et al. GCN 803, Dall
et al. GCN 804, Halpern et al. GCN 806) and consistent with it within our
errors. We identify this new X-ray source (1SAXJ1704.1+5147) as the X-ray
afterglow of GB000926.

This is an updated status of X-ray  observations programmed on this
source:

1- This BeppoSAX observation will last upto Sept. 29.046 (T_GRB+2 days) 

2- A fast Chandra TOO (Cycle 1 program by Piro et al) has been scheduled
for Sept. 29.67 (T_GRB+2.7 days) 

3- On the basis of the results of these 2 observation we will decide
whether to plan another BeppoSAX observation around T_GRB+6 days

4- Another Chandra observation should be performed by Kulkarni et al
(GCN808) at later times