GCN Circular 61

GRB980425


E. Pian, Istituto TESRE, CNR, Bologna, Italy, L. A. Antonelli, M. R.
Daniele, S. Rebecchi, SAX-SDC, Rome, Italy, V. Torroni, SAX-SOC, Rome,
Italy, G. Gennaro, SAX-OCC, Rome, Italy, M. Feroci, L. Piro, IAS, CNR,
Rome, Italy,

report:  "The BeppoSAX Wide Field Camera error box of GRB980425 (IAUC
6884) was observed with the BeppoSAX Narrow Field Instruments (NFI) 
starting about 10.0 hr after the burst in the period April 26.31-28.16 UT. 
Preliminary analysis of the data shows two previously unknown X-ray
sources in the LECS and MECS:  1SAXJ1935.0-5248 and 1SAXJ1935.3-5252,
located at RA = 19h35m04s, Dec = -52o48'33'' and at RA = 19h35m21s, Dec =
-52o52'19'' (equinox 2000.0), respectively, with an error radius of 1'
each.  These positions are 2' and 4'.7 away from the centroid of the WFC
error box, respectively.  During the first 27.7 hours of observation, the
average count rates in the two MECS units (1.6-10 keV) were (4.5 +-
0.7)x10E-3 cts/s, corresponding to (3.0 +- 0.4)x10E-13 erg sE-1 cmE-2 in
the 2-10 keV range, for 1SAXJ1935.0-5248 and (2.4 +- 0.5)x10E-3 cts/s for
1SAXJ1935.3-5252, equivalent to (1.6 +- 0.3)x10E-13 erg sE-1 cmE-2 (2-10
keV). The measurements during the subsequent 16.6 hours showed that
1SAXJ1935.0-5248 did not vary significantly from the first epoch. 
1SAXJ1935.3-5252 was not detected at the second epoch, with a 3 sigma
upper limit of 1.8x10E-3 cts/s.  This indicates a decay by a factor of 1.3
or more in 22 hours.  A further BeppoSAX observation is already planned to
monitor the behavior of both sources."