- GCN/HETE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Sat 28 Feb 04 00:08:59 UT
NOTICE_TYPE: HETE S/C_Alert
TRIGGER_NUM: 3066, Seq_Num: 1
GRB_DATE: 13063 TJD; 59 DOY; 04/02/28
GRB_TIME: 535.95 SOD {00:08:55.95} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 162 [cnts/s] on a 0.160 [sec] timescale
SC_LONG: 348 [deg East]
SUN_POSTN: 340.36d {+22h 41m 26s} -8.29d {-08d 17' 28"}
MOON_POSTN: 65.06d {+04h 20m 15s} +23.55d {+23d 32' 43"}
MOON_ILLUM: 49 [%]
COMMENTS: No s/c ACS pointing info available yet.
COMMENTS: Probable GRB.
- GCN/HETE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Sat 28 Feb 04 00:13:13 UT
NOTICE_TYPE: HETE S/C_Alert
TRIGGER_NUM: 3067, Seq_Num: 1
GRB_DATE: 13063 TJD; 59 DOY; 04/02/28
GRB_TIME: 764.08 SOD {00:12:44.08} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
WXM_SIG/NOISE: 0.1 sig/noise on a 6.720 [sec] timescale
SC_-Z_RA: 160 [deg]
SC_-Z_DEC: 9 [deg]
SC_LONG: 2 [deg East]
SUN_POSTN: 340.36d {+22h 41m 26s} -8.29d {-08d 17' 24"}
MOON_POSTN: 65.10d {+04h 20m 23s} +23.55d {+23d 33' 10"}
MOON_ILLUM: 49 [%]
COMMENTS: Probable GRB.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Sat 28 Feb 04 02:22:44 UT
NOTICE_TYPE: HETE Ground Analysis
TRIGGER_NUM: 3067, Seq_Num: 3
GRB_DATE: 13063 TJD; 59 DOY; 04/02/28
GRB_TIME: 764.08 SOD {00:12:44.08} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
WXM_SIG/NOISE: 0.1 sig/noise on a 6.720 [sec] timescale
SC_-Z_RA: 160 [deg]
SC_-Z_DEC: 9 [deg]
SC_LONG: 2 [deg East]
WXM_CNTR_RA: 153.051d {+10h 12m 12s} (J2000),
153.103d {+10h 12m 25s} (current),
152.427d {+10h 09m 42s} (1950)
WXM_CNTR_DEC: -7.326d {-07d 19' 33"} (J2000),
-7.347d {-07d 20' 48"} (current),
-7.079d {-07d 04' 43"} (1950)
WXM_CORNER1: 153.2320 -7.8100 [deg]
WXM_CORNER2: 152.8720 -7.7960 [deg]
WXM_CORNER3: 152.8700 -6.8430 [deg]
WXM_CORNER4: 153.2310 -6.8560 [deg]
WXM_MAX_SIZE: 61.88 [arcmin] diameter
WXM_LOC_SN: 9 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 3.3 Y= 2.1 [sig/noise]
WXM_LC_SN: X= 8.8 Y= 5.1 [sig/noise]
SUN_POSTN: 340.36d {+22h 41m 26s} -8.29d {-08d 17' 24"}
SUN_DIST: 162.77 [deg]
MOON_POSTN: 65.10d {+04h 20m 23s} +23.55d {+23d 33' 10"}
MOON_DIST: 91.12 [deg]
MOON_ILLUM: 49 [%]
GAL_COORDS: 248.91,38.31 [deg] galactic lon,lat of the burst
ECL_COORDS: 157.75,-17.21 [deg] ecliptic lon,lat of the burst
COMMENTS: Definite GRB.
COMMENTS: Burst_Validity flag is true.
COMMENTS: WXM data refined since S/C_Last Notice.
- GCN notice #2536
Y. Nakagawa, G. Ricker, J-L. Atteia, N. Kawai, D. Lamb, and S. Woosley,
on behalf of the HETE Science Team;
T. Donaghy, E. Fenimore, M. Galassi, C. Graziani, M. Matsuoka,
T. Sakamoto, R. Satoh, Y. Shirasaki, M. Suzuki, T. Tamagawa, K. Torii,
Y. Urata, T. Yamazaki, Y. Yamamoto, and A. Yoshida, on behalf of the
HETE WXM Team;
N. Butler, G. Crew, J. Doty, A. Dullighan, 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, C. Barraud, and K. Hurley, on behalf
of the HETE FREGATE Team;
report:
At 00:08:55.95s UTC (535.95s UT) and 00:12:44.08s UTC (764.08s UT) on
2004 February 28, the HETE-2 FREGATE instrument detected triggers H3066
and H3067. H3066 is a multi-peaked burst with a duration of ~40s in
the FREGATE 7-80 and 30-400 keV energy bands; no significant emission
associated with H3066 is seen in the WXM 2-25 keV energy band or in the
FREGATE 7-40 keV energy band. H3067 consists of a single peak with a
duration of ~10 seconds in the FREGATE 30-400 keV energy band; again,
no significant emission associated with H3067 is seen in the WXM 2-25
keV energy band or in the FREGATE 7-40 keV energy band.
At ~00:13:24 UTC (~800 UT) (~40 seconds after trigger H3067), an X-ray
pulse with a duration of >50 seconds is visible in the WXM 2-15 keV
energy band. Ground analysis of the WXM data produced a localization
that was reported in a GCN Notice at 02:22:44 UT. The WXM localization
can be expresssed as a 90% confidence rectangle whose center is at
WXM-ground: RA = +10h 12m 12s, Dec = -07d 19' 33" (J2000),
and whose corners lie at
WXM-ground: RA = +10h 12m 55.6s, Dec = -7d 48' 36"
RA = +10h 11m 29.3s, Dec = -7d 47' 46"
RA = +10h 11m 28.8s, Dec = -6d 50' 35"
RA = +10h 12m 55.4s, Dec = -6d 51' 22" (J2000).
The spectrum of the X-ray pulse is such that, had it been detected
alone, it would be classified as an XRF. However, the temporal
coincidence with the two preceding triggers suggests that the X-ray
pulse may be associated with them, and is in fact a soft late phase of
the GRB. Because we are unable to localize either H3066 or H3067, we
are unable to confirm this possibility at this time. An IPN
localization of either H3066 or H3067 could help to resolve the
situation, and to determine whether H3066, H3067, and the X-ray pulse
are all part of the same burst or not.
Light curves for H3066, H3067, and the X-ray pulse, and a skymap
showing the localization of the X-ray pulse is provided at the
following URL:
http://space.mit.edu/HETE/Bursts/GRB040228.
- GCN notice #2537
Y. Sarugaku (JAXA/ISAS),
T. Aoki, Y. Urata, K.Y. Huang, and T. Tamagawa on behalf of KISO
GRB Team report;
"We have observed the entire HETE-2 error region of GRB040228
(Nakagawa et al. GCN2536) with Kiso observatory 1.05 m Schmidt
telescope using 2kx2k CCD camera which field of view is 50 x 50
arcmin. We obtained Rc-band data sets (300 sec x 4 frames), starting
at Feb. 28 12:11 UT (0.5 days after the burst). The limiting magnitude
for each images is about 19.5 mag. Comparison with DSS II red images,
no new object was detected down to the limiting magnitude."
This message may be cited.
- GCN notice #2538
K. Hurley and T. Cline, on behalf of the Ulysses, HETE, Mars Odyssey,
and Konus GRB teams,
I. Mitrofanov, S. Charyshnikov, V. Grinkov, 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,
E. Mazets and S. Golenetskii, on behalf of the Konus-Wind 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:
Mars Odyssey (HEND and GRS) and Konus-Wind observed H3066 (GRB040228 at
00536 s, GCN 2536). In addition, Konus-Wind observed H3067 (GRB040228
at 00764 s) and the 50 s long X-ray pulse which followed it (GCN
2536). Neither of these was observed by Odyssey, but this is
consistent with the lower intensity of H3067, and the spectral softness
of the X-ray pulse (the Odyssey lower energy threshold is ~100 keV).
Ulysses was off.
We have triangulated H3066 to an annulus centered at RA, Decl (J2000) =
222.855, -17.387 degrees, whose radius is 31.387 +/- 0.055 degrees (3
sigma). The minimum distance between this annulus and the position of
the X-ray pulse determined by the HETE WXM is ~37 degrees; in addition,
this position is Mars-blocked to Odyssey. We therefore conclude that
H3066 and the X-ray pulse are unrelated.
Using Mars-blocking, the IPN annulus, and the Konus ecliptic latitude
determination, we can restrict the arrival direction of H3066 to that
portion of the annulus which lies between RA, Dec = 246, -42 degrees,
and 253, -33 degrees. This area was far outside the HETE WXM FOV,
further proof that H3066 and the X-ray pulse detected by the WXM are
unrelated.
However, Konus-Wind data indicate that the arrival directions of H3066,
H3067, and the X-ray pulse are all consistent with an ecliptic latitude
of -10 to -20 degrees. Thus H3067 may be related either to H3066 or to
the X-ray pulse (but not both). It may also be an independent event.
Finally, we note that the Odyssey data display a strong, 5 s long pulse
~350 s after the signal corresponding to H3066. We are investigating
the possible relation of this pulse to the other bursts.
- GCN notice #2539
H. Pedersen, Copenhagen University Observatory, on behalf of the GRACE team,
reports:
"The Descartes Optical Telescope, consisting of a parallactically mounted
F=24 mm, f/2.8 lens and a 1472 x 2184 pixel CCD (pixel size: 6.8 micron),
is currently undergoing tests at ESO, La Silla, during which serendipitous
observations of the GRB040228 error box (Nakagawa et al. GCN 2536, see
also Hurley et al. GCN 2538) were done on several nights starting February
22 d 1 h UTC. No filter was used, and all exposures lasted 30 s followed
by 30 s read-out. During each of the first five nights integrations
spanning several hours were obtained under mostly good conditions.
No observations were attempted on February 27. On the night of trigger
no. H3066 a partial clearing started more than an hour later. A set of 24
exposures obtained in the time interval from 75 to 99 minutes after the
trigger are of fairly uniform quality and have been co-added. No candidate
afterglow is seen in or near the error box to m(r) = 10.2, based on USNO
photometry of U0825_07125568, a star near the centre of the error box.
Observations taken in the time interval from 46 to 45 hours prior to the
GRB likewise give no indication of 'preglow', to a limit of m(r) = 10.5.
All values are preliminary and should not be published before further
confirmation."
- Info from the HETE page
HETE detected three bursts on February 28. The first two were
triggers H3066 and H3067: both were quite hard, and there was
no signal from either in the WXM. The third burst was seen in
the WXM shortly after H3067 and was localizable.
IPN observations confirm that H3066 and H3067 came from well
outside the WXM FOV; it is likely that these two are the same
burst, so we have designated both to be GRB040228A. The soft
pulse has been given the HETE untriggered burst number 11475
and is designated GRB040228B.
Previous IAU Circulars 