GRB 001204

K. Hurley, on behalf of the Ulysses GRB team, T. Cline, on behalf of
the Konus-Wind and NEAR GRB teams, F. Frontera, C. Guidorzi, and E.
Montanari, on behalf of the BeppoSAX GRBM team, and E. Mazets and S.
Golenetskii, on behalf of the KONUS-WIND GRB team, report:

Ulysses and NEAR have only recently emerged from an intense solar
proton event lasting approximately two weeks.  Ulysses, NEAR, BeppoSAX
GRBM, and KONUS-WIND observed this GRB at 28869 seconds.  Its spectrum
and duration place it firmly in the "short/hard" class of gamma-ray
bursts.  As observed by Ulysses, it had a duration of 
<0.5 seconds, a 25-100 keV fluence of approximately  3.7E-7 erg/cm2,
and a peak flux of approximately  6.8E-7 erg/cm2 s over 0.5 seconds.

We have triangulated it to a preliminary, 3 sigma error box with approximate area  18 square arcminutes, whose coordinates are:

 ERROR BOX CENTER:   2 h 41 m  8.59 s     12 o 53 '  46.31 " 
 ERROR BOX CORNER 1:  2 h 41 m 10.35 s     12 o 51 '  56.95 " 
 ERROR BOX CORNER 2:  2 h 40 m 50.39 s     12 o 51 '  35.60 " 
 ERROR BOX CORNER 3:  2 h 41 m 26.79 s     12 o 55 '  57.13 " 
 ERROR BOX CORNER 4:  2 h 41 m  6.83 s     12 o 55 '  35.67 " 

Because solar protons were still being recorded by Ulysses,
this burst was detected at slightly under 5 sigma significance
(statistical only), making it somewhat marginal.  However,
final consistency checks are now being carried out, and the
results will be communicated as soon as they are available.

E. Berger (Caltech) and D. A. Frail (NRAO), report on behalf of a larger
collaboration:

"Beginning on December 7.17 UT we observed the IPN error box of the
short/hard burst, GRB001204 (GCN #895
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 ) with the VLA at 1.43 and 4.86 GHz.  
We find no new sources, which are not cataloged in the NRAO VLA Sky Survey
(NVSS), with a flux density larger than 250 microJy (5-6 sigma) at 4.86
GHz.

This message may be cited.

K. Hurley, on behalf of the Ulysses GRB team, T. Cline, on behalf of
the Konus-Wind and NEAR GRB teams, F. Frontera, C. Guidorzi, and E.
Montanari, on behalf of the BeppoSAX GRBM team, and E. Mazets and S.
Golenetskii, on behalf of the KONUS-WIND GRB team, report:

We have now completed several consistency checks for the IPN position
of GRB001204 (GCN 895
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 ), including

1. Deriving the ecliptic latitude of the event using the Konus-WIND data, 

2. Deriving the possible arrival directions using the BeppoSAX GRBM data, 

3. Eliminating one possible IPN position using BeppoSAX Earth-blocking, and

4. Deriving an annulus by comparing the BeppoSAX GRBM and Konus-WIND data
(the two data sets with the best time resolution and signal-to-noise ratios).

As all of the results are consistent with the position given in GCN 895
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 ,
we conclude that this is indeed the correct error box for this event, despite
the somewhat marginal detection by Ulysses.

P.A. Price, T.S. Axelrod and B.P. Schmidt (RSAA, ANU) report:

"We have observed the error box of the short/hard GRB001204 (Hurley et al.,
GCN #895
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 , #897
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 ) with the robotic 50-inch telescope at Mount Stomlo Observatory
starting at 2000 Dec 7.42 (approximately 3 days after the burst).  Our 3x300s
exposures in R_MACHO cover the entire error box.  We find no optical transient
candidate on visual comparison of the combined image with the DSS-2 red scan,
to a limiting magnitude of R ~ 20.1 (based on USNO catalogue)."

This message may be cited.

P.M. Vreeswijk, E. Rol (Univ. of Amsterdam) report on behalf of a
larger collaboration:

The central 4.5'x4.5' of the error box of GRB 001204 (Hurley et al.,
GCN #895
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 ) was observed for 30 min. in Ks with the New Technology
Telescope (NTT) at the European Southern Observatory on December 9.14
and 14.02 UT, respectively 4.8 and 9.7 days after the burst. The
limiting magnitude (5-sigma, aperture radius of one FWHM, or 0.8") for
both epochs is Ks=20.0. No counterpart candidate is found.

We appreciate the assistance of the NTT team.