TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1461
SUBJECT: Further refinement to IPN error box for GRB020531
DATE:    02/07/25 22:59:37 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@sunspot.ssl.berkeley.edu>

K. Hurley and T. Cline, on behalf of the Ulysses, Mars Odyssey, 
and HETE GRB teams,

I. Mitrofanov, D. Anfimov, A.Kozyrev, M. Litvak and A. Sanin, on behalf of the
HEND/Odyssey GRB team,

W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on behalf of
the GRS/Odyssey GRB team, and

G. Ricker, J-L Atteia, N. Kawai, D. Lamb, S. Woosley, J. Doty, R.
Vanderspek, J. Villasenor, G. Crew, G. Monnelly, N. Butler, J.G.
Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R.
Manchanda, G. Pizzichini, Y. Shirasaki, C. Graziani, M. Matsuoka, T.
Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi,
T. Tavenner, T. Donaghy, M. Boer, J-F Olive, and J-P Dezalay, on
behalf of the HETE GRB team, report:

We have further refined the IPN error box of the short duration, hard
spectrum GRB020531 (GCN 1399, 1402, and 1407) using the final Ulysses
ephemeris and clock corrections.  The error box now has an area of
approximately 9 square arcminutes:

15 h 15 m 11.18 s  -19 o 24 ' 27.80 " (CENTER)
15 h 15 m 05.61 s  -19 o 23 ' 54.43 " (CORNER)    
15 h 15 m 20.22 s  -19 o 22 ' 00.52 " (CORNER)   
15 h 15 m 02.15 s  -19 o 26 ' 54.98 " (CORNER)    
15 h 15 m 16.75 s  -19 o 25 ' 01.16 " (CORNER) 

A map will be posted shortly at ssl.berkeley.edu/ipn3/020531.  In it,
"GCN 1407" indicates the previous IPN error box, "C" indicates the Chandra
sources reported in GCN 1415 and 1426, and "T" indicates the TAROT
sources reported in GCN 1408, 1420, and 1421.

We do not expect further improvements to this error box.