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GCN Circular 203

GRB990123, BeppoSAX-NFI X-ray afterglow detection
1999-01-23T18:47:56Z (25 years ago)
Luigi Piro at IAS/CNR Frascati <>
Luigi Piro on behalf of the BeppoSAX team report:

A BeppoSAX follow-up of GRB990123 initiated around 15:40 UT,
i.e.  6 hr after the burst.  Preliminary analysis of the first 20 minutes
of the data at SOC  shows a previously unknown strong source
(about 10**-11 c.g.s in the 1.6-10 keV) in the center of the WFC error circle.

Preliminary coordinates  are:
R.A.(2000)= 231.374
DEC(2000)= +44.758
The error radius is  1.5'.

Considering its strenght, this X-ray source is very likely the X-ray
afterglow of GB990123.  We will continue to observe it to monitor
its temporal evolution.
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