TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  298
SUBJECT: Refined IPN error box for GRB990506
DATE:    99/05/07 20:49:45 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@sunspot.ssl.berkeley.edu>

K. Hurley, on behalf of the Ulysses GRB team, C. Kouveliotou and R. M. Kippen,
on behalf of the BATSE GRB team, and T. Cline, on behalf of the NEAR GRB team,
report:

We have obtained a refined position for this burst using higher time
resolution data, and adding the data of the NEAR spacecraft.  This
results in a true error box, as opposed to just a triangulation
annulus.  This error box is consistent with that obtained from the
intersection of the Ulysses-BATSE annulus with the RXTE error circle,
and therefore confirms that the fading X-ray source is indeed related
to the GRB, but in this preliminary analysis, it does not reduce 
its size.

Thus the refined error box (area ~30 sq. arcmin.) is defined by the new 
Ulysses-BATSE annulus and the RXTE error circle.  The corners are at:

  RA(2000)                Dec(2000)
11 h 54 m 33 s      -26 o 50 ' 59 "
11 h 54 m 56 s      -26 o 40 ' 07 "
11 h 54 m 24 s      -26 o 49 ' 16 "
11 h 54 m 45 s      -26 o 39 ' 36 "

Reductions in the widths of the annuli of the order of a factor
of two or more will be possible.  An image may be viewed at
http://ssl.berkeley.edu/ipn3/990506.