[vsnet-grb-info 1946] GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3785
SUBJECT: GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE 
DATE:    05/08/12 21:49:31 GMT
FROM:    Joel Villasenor at MIT  <jsvilla at space.mit.edu>

M. Maetou, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley,
on behalf of the HETE Science Team;
     
M. Arimoto, T. Donaghy, E. Fenimore, M. Galassi, C. Graziani,
J. Kotoku, M. Matsuoka, Y. Nakagawa, T. Sakamoto, R. Sato,
Y. Shirasaki, M. Suzuki, T. Tamagawa, K. Tanaka, Y. Yamamoto,
and A. Yoshida, on behalf of the HETE WXM Team;
     
N. Butler, G. Crew, J. Doty, G. Prigozhin, R. Vanderspek,
J. Villasenor, J. G. Jernigan, A. Levine, G. Azzibrouck, J. Braga,
R. Manchanda, and G. Pizzichini, on behalf of the HETE Operations and
HETE Optical-SXC Teams;
     
M. Boer, J-F Olive, J-P Dezalay, and K. Hurley, on behalf of the HETE
FREGATE Team;
     
report:

The HETE FREGATE, WXM, and SXC instruments detected GRB 050807 
(=H3889) at 10:58:45 UT (39525 SOD) on 7 August 2005.  The correct 
WXM flight localization was first reported in a GCN Notice issued 
at 10:59:19 UT, which was 34s after the burst trigger.

Further WXM and SXC ground localizations were reported in a GCN
Notice issued at 13:47:18 UT.  The final WXM ground localization can
be expressed as an 8 by 48 arcminute box (90% confidence) that is
centered at

WXM-Ground:  RA = 20h 13m 27s, DEC = -36d 57' 06" (J2000)

and defined by the corners:

RA = 20h 13m 16s, DEC = -37d 21' 43"
RA = 20h 12m 40s, DEC = -37d 18' 54"
RA = 20h 13m 38s, DEC = -36d 32' 31"
RA = 20h 14m 14s, DEC = -36d 35' 20".

The SXC localization could only be localized along one axis,
and hence yields a 3 by 32 arcminute box that is centered at

SXC-Ground:  RA = 20h 13m 27s, DEC = -36d 56' 12" (J2000)

and defined by the corners:

RA = 20h 13m 39s, DEC = -36d 40' 23"
RA = 20h 13m 00s, DEC = -37d 11' 20"
RA = 20h 13m 14s, DEC = -37d 12' 18"
RA = 20h 13m 54s, DEC = -36d 40' 52".

The burst has a duration T_90 of ~55 seconds in 6-40 keV and 6-80 keV,
and a T_90 of ~28 seconds in 30-400 keV.  Preliminary spectral analyses
show the 2-30 keV fluence of GRB 050807 to be 1.3 x 10-6 ergs cm-2 and
the 30-400 keV fluence to be 2.2 x 10-6 ergs cm-2.  Thus, GRB 050807 
is classified as an "X-ray-rich" GRB.

A light curve, skymap, and spectral information for GRB 050807 are
provided at the following URL:

http://space.mit.edu/HETE/Bursts/GRB050807

This message may be cited.