GRB 980515

GB980515

Luigi Piro and Marco Feroci on behalf of the BeppoSAX team report:

A GRB (GB980515) was observed by the BeppoSAX GRBM
at about 17:00:10 UT of May 15.
The event was detected by one of the WFC (WFC2).
The updated WFC position is:
   RA(2000)=319.518
   Dec(2000)=-67.249
The  error radius  is still of 5'.  A further refinement
of the WFC position should be available next Monday.

The BeppoSAX follow-up with the NFI should start around 2 AM UT of May 16.

Marco Feroci and Jean in 't Zand 
on behalf of the BeppoSAX Mission Scientist report:

The BeppoSAX-WFC position of GRB980515 has been revised using the
Final Observing Tape.

The revised burst position is:

R.A. = 319.3527 (21h 17m 25s), Decl. = -67.2550 (-67o 15' 18") Eq. 2000.0

We give an error radius of 4 arcmin.  This is somewhat larger than the usual
3 arcmin because of low statistics of the burst.
This position lies at 3.8 arcmin from the latest distributed position,
and 2.6 arcmin from the first distributed position.

Marco Feroci on behalf of the BeppoSAX team reports the following
submission to the IAU Circulars:                      


GRB 980515
   M. Feroci and L. Piro, Istituto Astrofisica Spaziale, CNR, Rome; 
M.R. Daniele, G. Gennaro, S. Rebecchi, and G. Celidonio, BeppoSAX Science
Operation Center, Rome; L.A. Antonelli, BeppoSAX Science Data Center, Rome;
and J. Heise, Space Research Organization of the Netherlands, Utrecht,
report:
"The BeppoSAX Wide Field Camera error box of GRB 980515 was
observed with the BeppoSAX Narrow Field Instruments (NFI) starting
on May 16.1178 UT (10 hr after the burst).  A previously unknown
x-ray source, 1SAX J2116.8-6712, was detected by the MECS (units 2
and 3) at R.A. = 21h16m49s, Decl. = -67o11'.8 (equinox 2000.0;
preliminary error radius 1'.5 due to the poor statistical quality).  
This position is 4'.9 from the centroid of the WFC position (GCN #73
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 ).  
The source 1SAX J2116.8-6712 exhibits a moderate variability 
over the two-day NFI observation.  There is no clear evidence for 
a monotonic decaying behaviour.  The average countrate was 
0.0026 +/- 0.0006 count/s (2-10 keV) in the two MECS units, 
corresponding to (1.6 +/- 0.4) x 10E-13 erg cmE-2 sE-1 (assuming a 
Crab-like energy spectrum).  At this time 1SAX J2116.8-6712 is the 
only candidate as the x-ray afterglow of GRB 980515".