- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 21 Oct 05 13:22:00 UT
NOTICE_TYPE: HETE S/C_Alert
TRIGGER_NUM: 3947, Seq_Num: 1
GRB_DATE: 13664 TJD; 294 DOY; 05/10/21
GRB_TIME: 48116.60 SOD {13:21:56.60} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 189 [cnts/s] on a 1.300 [sec] timescale
SC_LONG: 196 [deg East]
SUN_POSTN: 206.24d {+13h 44m 58s} -10.85d {-10d 51' 01"}
MOON_POSTN: 77.38d {+05h 09m 30s} +27.74d {+27d 44' 06"}
MOON_ILLUM: 82 [%]
COMMENTS: No s/c ACS pointing info available yet.
COMMENTS: Probable GRB.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 21 Oct 05 13:22:11 UT
NOTICE_TYPE: HETE S/C_Update
TRIGGER_NUM: 3947, Seq_Num: 2
GRB_DATE: 13664 TJD; 294 DOY; 05/10/21
GRB_TIME: 48116.60 SOD {13:21:56.60} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 189 [cnts/s] on a 1.300 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 10 [deg]
SC_LONG: 196 [deg East]
WXM_CNTR_RA: 29.234d {+01h 56m 56s} (J2000),
29.311d {+01h 57m 15s} (current),
28.572d {+01h 54m 17s} (1950)
WXM_CNTR_DEC: +9.100d {+09d 06' 01"} (J2000),
+9.128d {+09d 07' 43"} (current),
+8.857d {+08d 51' 24"} (1950)
WXM_MAX_SIZE: 60.00 [arcmin] diameter
WXM_LOC_SN: 3 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 2.5 Y= 3.0 [sig/noise]
WXM_LC_SN: X= 2.0 Y= 2.7 [sig/noise]
SUN_POSTN: 206.24d {+13h 44m 58s} -10.85d {-10d 51' 01"}
SUN_DIST: 176.52 [deg]
MOON_POSTN: 77.38d {+05h 09m 30s} +27.74d {+27d 44' 06"}
MOON_DIST: 48.86 [deg]
MOON_ILLUM: 82 [%]
GAL_COORDS: 148.85,-50.45 [deg] galactic lon,lat of the burst
ECL_COORDS: 30.39,-2.68 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 21 Oct 05 13:22:33 UT
NOTICE_TYPE: HETE S/C_Update
TRIGGER_NUM: 3947, Seq_Num: 3
GRB_DATE: 13664 TJD; 294 DOY; 05/10/21
GRB_TIME: 48116.60 SOD {13:21:56.60} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 189 [cnts/s] on a 1.300 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 10 [deg]
SC_LONG: 196 [deg East]
WXM_CNTR_RA: 29.122d {+01h 56m 29s} (J2000),
29.199d {+01h 56m 48s} (current),
28.460d {+01h 53m 50s} (1950)
WXM_CNTR_DEC: +9.151d {+09d 09' 03"} (J2000),
+9.179d {+09d 10' 44"} (current),
+8.907d {+08d 54' 24"} (1950)
WXM_MAX_SIZE: 28.00 [arcmin] diameter
WXM_LOC_SN: 13 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 8.5 Y= 10.5 [sig/noise]
WXM_LC_SN: X= 7.0 Y= 11.5 [sig/noise]
SUN_POSTN: 206.24d {+13h 44m 58s} -10.85d {-10d 51' 01"}
SUN_DIST: 176.64 [deg]
MOON_POSTN: 77.38d {+05h 09m 30s} +27.74d {+27d 44' 06"}
MOON_DIST: 48.94 [deg]
MOON_ILLUM: 82 [%]
GAL_COORDS: 148.66,-50.44 [deg] galactic lon,lat of the burst
ECL_COORDS: 30.30,-2.59 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 21 Oct 05 13:22:45 UT
NOTICE_TYPE: HETE S/C_Update
TRIGGER_NUM: 3947, Seq_Num: 4
GRB_DATE: 13664 TJD; 294 DOY; 05/10/21
GRB_TIME: 48116.60 SOD {13:21:56.60} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 189 [cnts/s] on a 1.300 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 10 [deg]
SC_LONG: 196 [deg East]
WXM_CNTR_RA: 29.105d {+01h 56m 25s} (J2000),
29.182d {+01h 56m 44s} (current),
28.444d {+01h 53m 46s} (1950)
WXM_CNTR_DEC: +9.147d {+09d 08' 48"} (J2000),
+9.175d {+09d 10' 30"} (current),
+8.903d {+08d 54' 10"} (1950)
WXM_MAX_SIZE: 28.00 [arcmin] diameter
WXM_LOC_SN: 16 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 10.7 Y= 12.2 [sig/noise]
WXM_LC_SN: X= 9.0 Y= 12.2 [sig/noise]
SUN_POSTN: 206.24d {+13h 44m 58s} -10.85d {-10d 51' 01"}
SUN_DIST: 176.65 [deg]
MOON_POSTN: 77.38d {+05h 09m 30s} +27.74d {+27d 44' 06"}
MOON_DIST: 48.95 [deg]
MOON_ILLUM: 82 [%]
GAL_COORDS: 148.64,-50.45 [deg] galactic lon,lat of the burst
ECL_COORDS: 30.29,-2.59 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 21 Oct 05 13:28:47 UT
NOTICE_TYPE: HETE S/C_Last
TRIGGER_NUM: 3947, Seq_Num: 5
GRB_DATE: 13664 TJD; 294 DOY; 05/10/21
GRB_TIME: 48116.60 SOD {13:21:56.60} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 189 [cnts/s] on a 1.300 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 10 [deg]
SC_LONG: 196 [deg East]
WXM_CNTR_RA: 29.105d {+01h 56m 25s} (J2000),
29.182d {+01h 56m 44s} (current),
28.444d {+01h 53m 46s} (1950)
WXM_CNTR_DEC: +9.147d {+09d 08' 48"} (J2000),
+9.175d {+09d 10' 30"} (current),
+8.903d {+08d 54' 10"} (1950)
WXM_MAX_SIZE: 28.00 [arcmin] diameter
WXM_LOC_SN: 16 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 10.7 Y= 12.2 [sig/noise]
WXM_LC_SN: X= 9.0 Y= 12.2 [sig/noise]
SUN_POSTN: 206.24d {+13h 44m 58s} -10.85d {-10d 51' 01"}
SUN_DIST: 176.65 [deg]
MOON_POSTN: 77.38d {+05h 09m 30s} +27.74d {+27d 44' 06"}
MOON_DIST: 48.95 [deg]
MOON_ILLUM: 82 [%]
GAL_COORDS: 148.64,-50.45 [deg] galactic lon,lat of the burst
ECL_COORDS: 30.29,-2.59 [deg] ecliptic lon,lat of the burst
COMMENTS: Probable GRB.
COMMENTS: WXM error box is circular; not rectangular.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 21 Oct 05 14:25:34 UT
NOTICE_TYPE: HETE Ground Analysis
TRIGGER_NUM: 3947, Seq_Num: 6
GRB_DATE: 13664 TJD; 294 DOY; 05/10/21
GRB_TIME: 48116.60 SOD {13:21:56.60} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 189 [cnts/s] on a 1.300 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 10 [deg]
SC_LONG: 196 [deg East]
WXM_CNTR_RA: 29.102d {+01h 56m 24s} (J2000),
29.179d {+01h 56m 43s} (current),
28.440d {+01h 53m 46s} (1950)
WXM_CNTR_DEC: +9.118d {+09d 07' 05"} (J2000),
+9.146d {+09d 08' 46"} (current),
+8.874d {+08d 52' 26"} (1950)
WXM_MAX_SIZE: 15.00 [arcmin] diameter
WXM_LOC_SN: 16 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 14.0 Y= 14.0 [sig/noise]
WXM_LC_SN: X= 15.0 Y= 22.0 [sig/noise]
SUN_POSTN: 206.24d {+13h 44m 58s} -10.85d {-10d 51' 01"}
SUN_DIST: 176.64 [deg]
MOON_POSTN: 77.38d {+05h 09m 30s} +27.74d {+27d 44' 06"}
MOON_DIST: 48.97 [deg]
MOON_ILLUM: 82 [%]
GAL_COORDS: 148.65,-50.48 [deg] galactic lon,lat of the burst
ECL_COORDS: 30.28,-2.62 [deg] ecliptic lon,lat of the burst
COMMENTS: Definite GRB.
COMMENTS: WXM error box is circular; not rectangular.
COMMENTS: Burst_Validity flag is true.
COMMENTS: WXM data refined since S/C_Last Notice.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 21 Oct 05 14:59:49 UT
NOTICE_TYPE: HETE Ground Analysis
TRIGGER_NUM: 3947, Seq_Num: 7
GRB_DATE: 13664 TJD; 294 DOY; 05/10/21
GRB_TIME: 48116.60 SOD {13:21:56.60} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 189 [cnts/s] on a 1.300 [sec] timescale
SC_-Z_RA: 2 [deg]
SC_-Z_DEC: 10 [deg]
SC_LONG: 196 [deg East]
WXM_CNTR_RA: 29.102d {+01h 56m 24s} (J2000),
29.179d {+01h 56m 43s} (current),
28.440d {+01h 53m 46s} (1950)
WXM_CNTR_DEC: +9.118d {+09d 07' 05"} (J2000),
+9.146d {+09d 08' 46"} (current),
+8.874d {+08d 52' 26"} (1950)
WXM_MAX_SIZE: 14.67 [arcmin] diameter
WXM_LOC_SN: 3 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 14.0 Y= 14.0 [sig/noise]
WXM_LC_SN: X= 15.0 Y= 22.0 [sig/noise]
SXC_CNTR_RA: 29.112d {+01h 56m 27s} (J2000),
29.189d {+01h 56m 45s} (current),
28.451d {+01h 53m 48s} (1950)
SXC_CNTR_DEC: +9.077d {+09d 04' 37"} (J2000),
+9.105d {+09d 06' 19"} (current),
+8.833d {+08d 49' 59"} (1950)
SXC_CORNER1: 29.0080 9.0340 [deg]
SXC_CORNER2: 29.2250 9.0879 [deg]
SXC_CORNER3: 29.2280 9.1230 [deg]
SXC_CORNER4: 28.9880 9.0630 [deg]
SXC_MAX_SIZE: 14.67 [arcmin] diameter
SXC_LOC_SN: 3 sig/noise (pt src in image)
SUN_POSTN: 206.24d {+13h 44m 58s} -10.85d {-10d 51' 01"}
SUN_DIST: 176.61 [deg]
MOON_POSTN: 77.38d {+05h 09m 30s} +27.74d {+27d 44' 06"}
MOON_DIST: 48.98 [deg]
MOON_ILLUM: 82 [%]
GAL_COORDS: 148.69,-50.51 [deg] galactic lon,lat of the burst
ECL_COORDS: 30.27,-2.66 [deg] ecliptic lon,lat of the burst
COMMENTS: Definite GRB.
COMMENTS: WXM error box is circular; not rectangular.
COMMENTS: Burst_Validity flag is true.
COMMENTS: WXM data refined since S/C_Last Notice.
COMMENTS: SXC data refined since S/C_Last Notice.
- GCN notice #4116
A. Yoshida, 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,
N. Ishikawa, A. Kobayashi, J. Kotoku, M. Maetou, M. Matsuoka,
Y. Nakagawa, T. Sakamoto, R. Sato, T. Shimokawabe, Y. Shirasaki,
S. Sugita, M. Suzuki, T. Tamagawa, and K. Tanaka, 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 051021
(=H3947) at 13:21:57 UT (48117 SOD) on 21 October 2005. The
WXM flight localization was first reported in a GCN Notice issued
at 13:22:11 UT, which was 14s after the burst trigger.
Ground analysis of the WXM data produced a refined WXM localization that
was issued in a GCN Notice at 14:25:34 UT. This ground WXM localization
can be expressed as a circle of 7.5 arcminutes radius (90% confidence),
centered at
R.A. = 01h 56m 24s ; Dec. = +09d 07' 05" (J2000).
The SXC detected this event in its Y camera. Ground analysis of the SXC
data therefore produced a 1-dimensional location. The intersection of
this location with the WXM ground location was issued in a GCN Notice at
14:59:49 UT. This location can be expressed as a box with corners:
R.A. = 01h 56m 01.92s ; Dec. = +09d 02' 02.4"
R.A. = 01h 56m 54.00s ; Dec. = +09d 05' 16.4"
R.A. = 01h 56m 54.72s ; Dec. = +09d 07' 22.8"
R.A. = 01h 59m 57.12s ; Dec. = +09d 03' 46.8" (J2000).
Further analysis is in progress.
- GCN notice #4118
V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski, E.Gorbovskoy,
A.Krylov, G.Borisov, A.Sankovich, V.Vladimirov
Sternberg Astronomical Institute, Moscow Union 'Optic'
MASTER robotic system (http://observ.pereplet.ru) responded to
GRB051021.6 at 2002-10-21 15:39:37 under the bad weather conditions
after sunset.
An automated response took the first image at 01h 28min after the GRB
time.
The unfiltered image is calibrateds relative to USNO A2.0 (0.8 R + 0.2 B).
The robot not find OT-candidate in error box.
Our upper limit is about 14.0 m.
The reduction is continuing.
The JPG-image will be available at
http://observ.pereplet.ru/images/GRB051021.6/1.jpg.
This work is supported by RFFI 04-02-16411 grant.
This message can be cited.
- GCN notice #4119
V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski, E.Gorbovskoy,
A.Krylov, G.Borisov, A.Sankovich, V.Vladimirov
Sternberg Astronomical Institute, Moscow Union 'Optic'
MASTER robotic system (http://observ.pereplet.ru) responded to
GRB051021.63 (Swift triger 53550) at 2005-10-21 15:03:09.46
An automated response took the first image at 2005-10-21 16:14:29 UT,
+01:11:19.54 after the GRB time
The unfiltered image is calibrateds relative to USNO A2.0 (0.8 R + 0.2 B).
The robot not find OT-candidate in error box.
Our upper limit is about 16.3 m.
The previouse circular number 4118 was about HETE Alert 3947.
The reduction is continuing.
The JPG-image will be available at
http://observ.pereplet.ru/images/GRB051021.63/1.jpg .
This work is supported by RFFI 04-02-16411 grant.
This message can be cited.
Mailto: lipunov@sai.msu.ru
- GCN notice #4120
D.B. Fox (Penn State), with R. McNaught and B. Peterson (RSAA/ANU),
report on behalf of a larger collaboration:
"We have observed the HETE localization region for GRB051021 (Yoshida
et al., GCN 4116) with the 40-inch telescope at Siding Spring
Observatory, in a sequence of R-band exposures beginning at 13:48:48
UT (26m51s after the burst). Comparison of a coadded image with mean
epoch 14:34:33 (1h12m post-burst) to the Digitized Sky Survey reveals
the presence of a new R~18.5 mag source, at coordinates:
R.A. 01:56:36.39, Dec +9:04:03.7 (J2000)
with a coordinate uncertainty, relative to USNO-B1.0 catalog
astrometry, of <0.5". Inspection of our individual images suggests
fading of the source over the ~1 hour span of our observations.
However, in the absence of a more sophisticated reduction of these
data it is not possible to make a firm conclusion as to variability at
this time. Moreover, the presence of a cosmetic defect at the source
position in one image introduces significant uncertainty to our
mean photometric estimate, above.
We suggest that this source may be the optical afterglow of
GRB051021."
- GCN notice #4121
H. Swan (U Mich), T.A. McKay (U Mich), D.A. Smith (Guilford), B.
Schaefer (Louisiana State), E.S. Rykoff (U Mich), F. Yuan (U Mich),
report on behalf of the ROTSE collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded
to GRB 051021 (HETE trigger 3947). The first image was at 13:22:28.4 UT,
31.8 s after the burst (6.6 s after the GCN notice time). The unfiltered
images are calibrated relative to USNO A2.0. We confirm the presence of
the source detected by Fox et. al. GCN # 4120. We observe the source to
rise to 16.9 magnitude, at about 180 seconds, and then fade by half a
magnitude over a period of 150 seconds.
This source is not visible in DSS (second epoch), 2MASS or the MPChecker
database.
Continuing observations are in progress.
- GCN notice #4122
P. Tristram (Univ. of Canterbury, New Zealand),S. Guziy,
A. de Ugarte Postigo, Shashi. B. Pandey, A. J. Castro-Tirado,
M. Jelinek, J. Gorosabel (IAA-CSIC, Granada, Spain),
and Ph. Yock (Univ. of Auckland, New Zealand)
report:
"We have observed the region centered around the HETE error box
for GRB 051021 (Yoshida et al.2005, GCN 4116) with
0.6 m telescope at Mount John observatory (New Zealand), starting
on October 21 ( 14:10 UT, 45 minutes after the GRB). We confirm the
optical candidate reported by Fox et al. (GCN, 4120)."
Further observations are in progress.
This massage can be cited.
- GCN notice #4123
GRB 051021 : optical afterglow observation at Lulin
H.H. Hsieh (IfAUH), M.S. Chang, K.Y. Huang, W.H. Ip (NCU), Y. Urata
(RIKEN), Y. Qiu (BAO) on behalf of the East Asian collaboration
report:
The R-band observations of GRB 051021 (Yoshida et al., GCN 4116) were
taken by Lulin 1-m telescope, Taiwan. The optical afterglow reported
by Fox et al.(GCN 4120) was detected clearly in our R-band
images. Compared with USNOB stars, the R band magnitude of afterglow
is about 19.8 at 15.859 UT (~ 2.48 hrs after the burst).
Further observations are on going.
This message may be cited.
- GCN notice #4124
J-F Olive, 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,
N. Ishikawa, A. Kobayashi, J. Kotoku, M. Maetou, M. Matsuoka,
Y. Nakagawa, T. Sakamoto, R. Sato, T. Shimokawabe, Y. Shirasaki,
S. Sugita, M. Suzuki, T. Tamagawa, K. Tanaka, 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-P Dezalay, and K. Hurley, on behalf of the HETE FREGATE
Team;
report:
We have analyzed the full FREGATE+WXM data for HETE trigger H3934
(GRB051021.56).
The 30-400 keV light curve has two sharp peaks, separated by about 10 s,
superposed on a gentler rise-and-fall. The burst had a T90 duration of 38s
in the 7-40 keV band, and of 27s in the 30-400 keV band. Emission in the
2-25 keV band appears to continue for at least 90s post-trigger, mostly
below 10 keV.
The integrated spectrum is well-fit by a cutoff power-law function. The
best-fit parameters are:
alpha = -1.16 --- 90% confidence interval is [-1.25 -1.06]
Epeak = 94.2 --- 90% confidence interval is [76.7 , 111.7]
The 2-30 keV fluence is 3x10^-6 erg/cm2, while the 30-400 keV fluence is
6 x 10^-6 keV. Since the ratio S(2-30)/S(30-400) is 0.41, this event is
classified as an X-Ray Rich GRB.
The pseudo-redshift estimated for this burst is pz = 1.4.
A light curve, a skymap, and spectral information for this event are
provided at the following URL:
http://space.mit.edu/HETE/Bursts/GRB051021
- GCN notice #4125
J. Racusin, J. Kennea, D. Morris, D. Fox, D. Burrows (PSU), N. Gehrels
(GSFC) on behalf of the Swift XRT team:
XRT began observing GRB051021 (Yoshida et al., GCN 4116) at 16:28:28 UT,
approximately 3 hours after the HETE trigger. From the first 2 orbits of
data, we detect an uncatalogued fading X-ray source at:
RA(J2000): 01:56:36.4
Dec(J2000): +09:04:06.3
with an estimated uncertainty of 4 arcseconds (90% containment).
This position is 4.3 arcminutes from the HETE position reported by Yoshida
et al.(GCN 4116), and 2.7 arcseconds from the optical afterglow position
reported by Fox et al.(GCN 4120).
At the time of these observations using 4.7 ks of data, the measured flux
was 2.7x10^-12 ergs/cm^2/s. Further observations are necessary to measure
the lightcurve decay slope.
- GCN notice #4127
J. Haislip, M. Nysewander, E. Cypriano, D. Reichart, M. Bayliss report on
behalf of the UNC Team of the FUN GRB Collaboration:
The SOAR-4.1m Telescope at CTIO began imaging the afterglow of the HETE GRB
051021 (Yoshida et al., GCN 4116; Fox et al., GCN 4120) at 01:38:51 UT,
12.3 hours after the burst in YJHKs.
We detect the afterglow at a magnitude of J = 17.16 +- 0.06 based on three
2MASS stars at a mean time of 01:47:19.2 UT, 12.4 hours after the GRB.
- GCN notice #4129
E.Sonoda,S.Maeno,Y.Tokunaga, M.Yamauchi
(University of Miyazaki)
"We have observed the field covering the SXC error box of
GRB051021(HETE trigger 3947; trigger time 13:21:5 UT ) with the
unfiltered CCD camera on the 30-cm telescope at University of
Miyazaki.The observation was started 13:22:30 UT on Oct.21.
We have compared our image with the USNO A2.0 catalog .
Preliminary analysis shows there is no new source brighter than 14.3 mag.
at the position reported by D.B.Fox et al.(GCN4120). "
- GCN notice #4136
P. J. Brown (PSU), D. Fox (PSU), M. Trippico (GSFC-SSAI),
J. Nousek (PSU), & N. Gehrels (GSFC)
on behalf of the Swift/UVOT team report:
The Swift-UVOT began observing the field of
GRB 051021 (HETE Trigger H3947; Yoshida et al. GCN 4116)
at 2005-10-21 16:28:27, about 3 hours after the burst.
No source is detected at the position of the optical
counterpart found by Fox, McNaught, & Peterson (GCN 4120)
in any of our 6 filters down to the following 3-sigma
upper limits:
Filter T_range(hours) Exp(sec) 3sigUL
V 3.36-8.34 1988 20.2
B 5.30-6.71 1304 21.1
U 5.04-5.29 900 20.5
W1 4.79-5.04 900 20.8
M2 3.61-3.80 900 20.9
W2 3.11-6.96 1800 21.7
Where T_range is time post-trigger.
- GCN notice #4138
J. Eastman, D. L. Depoy (Ohio State U.), A. P. Crotts, & D. J. Beirne
(Columbia U.) observed the afterglow (Fox et al., GCN 4120) of
HETE GRB 051021 (Yoshida et al., GCN 4116; Olive et al., GCN 4124)
in the R band using the MDM 1.3m, and in SDSS r using the MDM 2.4m.
On Oct. 22 04:45 UT, 15.4 hours after the burst, they report a 5-sigma
upper limit of R > 23.0. Compared with the Lulin measurement of R=19.8
at 2.5 hours (Hsieh et al., GCN 4123), this indicates a mean temporal
decay index steeper than -1.6, possibly a jet break. In combination
with the bright near-IR detection by Haislip et al. (GCN 4127), J=17.16
at 12.4 hours, and if the decay index between 12.4 and 15.4 hours is
not steeper than -3.5, the implied R-J color is greater than 5, which
requires a high redshift.
- GCN notice #4140
S. Bradley Cenko, Chris Conselice, Kevin Bundy, (Caltech), Derek B. Fox
(Penn State), and Edo Berger (Carnegie), report on behalf of the
Caltech-NRAO-Carnegie GRB collaboration:
"We have imaged the field of GRB 051021 (Yoshida et al., GCN 4116) with
the Wide Field Infrared Camera mounted on the Palomar 200" Hale Telescope.
Our images consisted of 9 x 120 s exposures taken in the Ks filter at a
mean epoch of approximately 22 October 5:24 UT (~ 16 hours after the
burst). We find at best a marginal (< 3-sigma) detection at the location
of the OT (Fox et al., GCN 4120). Our 3-sigma limiting magnitude,
calculated with respect to several 2mass stars in the field, is
approximately Ks > 19.0.
We note that under the standard afterglow model, our result is
inconsistent with the J-band detection reported by Haislip et. al (GCN
4127), and therefore calls into question the interpreration of GRB 051021
as a high redshift event."
- GCN notice #4142
B. E. Cobb and C. D. Bailyn (Yale), part of the larger SMARTS
consortium, report:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 051021
(GCN 4116, Yoshida et al.) with a mid-exposure time of
2005-10-22 02:53 UT, which is ~13.5 hours post-burst.
Total summed exposure times amounted to 36 minutes in I and 30
minutes in J.
At the position of the reported afterglow (GCN 4120, Fox et al.), an
object is marginally detected in our I-band images. The preliminary
magnitude of this object is determined to be I = 22.0 +/- 0.4, in
comparison with several nearby USNO B1.0 stars.
The afterglow candidate is not, however, detected in the J-band. Using
several 2MASS comparison stars, the limiting magnitude of this image
is determined to be J > 19.9 +/- 0.1.
There is an object near to the position of the afterglow candidate
(at RA = 1:56:35.6, Dec = 9:04:26.2) that is measured in our image
to have a magnitude of J = 17.2 +/- 0.1. This object is below the
detection limits of 2MASS, so it is not detected in the 2MASS
images (though it is present in the USNO B1.0 survey). Possibly, this is
the object reported by Haislip et al. (GRB 4127). Therefore, in agreement
with Cenko et al. (GCN 4140), there is not yet clear evidence
to suggest that this is a high redshift event.
- GCN notice #4144
D. Reichart reports on behalf of the UNC team of the FUN GRB Collaboration:
Cobb & Bailyn (GCN 4142) are correct. The correct J magnitude at 12.3
hours after the burst is 20.3 +/- 0.2 mag.
Using 4.1m SOAR, we observed the afterglow in BVRIYJHKs. We will report on
the SFD in a forthcoming GCN.
- GCN notice #4147
M. Nysewander, C. Macleod, D. Reichart, A. Crain, A. Foster report on
behalf of the UNC team of the FUN GRB Collaboration:
Under the control of Skynet, PROMPT observed the localization of GRB 051021
(Yoshida et al., GCN 4116; Fox et al., GCN 4120) beginning 12.9 hours after
the burst, in Rc and Ic simultaneously.
We do not detect the afterglow of the burst. In two 90 x 60 sec
integrations of mean epoch 14.2 hours after the burst, we measure 3-sigma
limiting magnitudes of Rc = 20.7 and Ic = 20.4 based on 5 USNO-B1.0 stars.
PROMPT is still being built and commissioned.
- GCN Circular #4151
J. Racusin, D. Fox, D. Burrows (PSU), N. Gehrels (GSFC) on behalf of the
Swift XRT team:
We have analyzed the first four orbits of data after XRT began observing
the field of GRB051021A (Yoshida et al., GCN 4116) at 16:28:28 UT. The
refined XRT coordinates are:
RA(J2000): 01 56 36.5
Dec(J2000): +09 04 6.1
with an estimated uncertainty of 4 arcseconds (90% containment), including
corrections for the XRT boresight offset. This position is 1 arcsecond
from the position we quoted in Racusin et al. (GCN 4125), and 2.9
arcseconds from the optical afterglow candidate reported by Fox et al.
(GCN 4120).
The XRT light curve shows a steady decline with a power-law fit decay
index of 1.06+/-0.16.
The Photon Counting mode spectra can be fit with an absorbed power-law
with a photon index of 2.17+/-0.18 and a column density of 1.4+/-0.5 E21
cm-2 which is in excess of the Galactic column density of 0.56E21 cm-2 in
this direction. The observed 0.2-10 keV flux is 2.02E-12 ergs cm-2 s-1,
corresponding to an unabsorbed flux of 2.28E-12 ergs cm-2 s-1.
- GCN Circular #4159
V.Rumyantsev (CrAO), V.Biryukov (SAI, MSU), and A.Pozanenko (IKI) on behalf
of larger GRB follow up collaboration report:
We observed the SXC error box of HETE-2 GRB051021a (Yoshida et al.,
GCN4116) with 0.6 m telescope (Crimean laboratory of SAI) equipped with FLI
IMG-1001E camera. The series of 60 sec R-band exposures were taken between
October 21, 21:19:01 and October 22, 00:23:24. We clearly detect the
optical afterglow (Fox et al. GCN4120, Swan et al. GCN4120) on stacked
image. Coordinates of the source are RA=01 56 36.37 Dec=+09 04 03.27 (J2000)
with uncertainty of 0.5 arcsec. Preliminary photometry of the stacked image
is following:
Mid time (UT) Exposure R
Oct. 21 22:51 146x60 21.9 +/-0.2
Photometry and astrometry of the source are based on USNO-A2.0.
Stacked image can be found in
http://grb.rssi.ru/GRB051021a/
Taken R-band magnitudes (GCNs 4120, 4123) and upper limit reported in
GCN4138 (Eastman et al.) our results is compatible within statistical error
with single power-law decay light curve alpha ~ -1.6. Also extrapolating
backward J-band (Reichart et al., GCN 4144) observations to our epoch (Oct.
21 22:51) we found R-J ~ 1.0 which do not imply a high redshift source.
This message may be cited.
- GCN Circular #4166
Kuntal Misra (ARIES, Nainital) and Atish P. Kamble (Raman Research
Institute, Bangalore) on behalf of a larger Indian GRB collaboration
We observed the field of GRB 051021 (HETE trigger 3947) using the 104 cm
reflector telescope at ARIES, Nainital. We do not find any new source upto
a limiting magnitude of 21 in our combined (exposure 3*300 sec) R band
images on October 22.675 UT with respect to five nearby USNO-A2.0 stars.
This message may be cited.
- GCN Circular #4180
R. Burenin, D. Denisenko, M. Pavlinsky, R. Sunyaev (IKI), I. Khamitov,
Z. Aslan (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.),
I. Bikmaev, N. Sakhibullin (KSU/AST)
report:
The optical transient associated with GRB 051021A (Yoshida et al., GCN
4116; Fox et al., GCN 4120) was observed with Russian-Turkish 1.5-m
telescope (RTT150, Bakyrlytepe, TUBITAK National Observatory, Turkey) in
BVR filter set, starting at Oct. 21, 18:15 UT, 4.88 hours after the
burst.
Compared to USNOB, the magnitudes are about:
t-t0,h
5.34 R=21.1
9.95 R=21.8
5.70 V=22.2
10.18 V=22.6
In B the object was detected only marginally.
This message may be cited.
- GCN notice #4184
A. Henden (AAVSO/USNO) reports on behalf of the USNO GRB Team:
We have acquired UBVRcIc all-sky photometry for 23x23arcmin
fields centered on the coordinates of recent GRB localizations
with the USNOFS 1.0-m telescope on 1 or 2 photometric nights.
We are using a new CCD, and so place an additional zeropoint
error of about 0.03mag that should be added in quadrature
to the errors reported in the files listed below.
Stars brighter than V=13.0 are saturated and should be used
with care. We have placed the photometric data on our
anonymous ftp site:
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb050505.dat
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb051021.dat
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb051022.dat
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb051028.dat
Since these bursts had identified optical afterglows, we may
improve the photometric calibration on subsequent observing runs.
As always, you should check the dates on the .dat file prior to
final publication to get the latest photometry. There is
a README file on the ftp directory to give you information
about the procedures used to calibrate these fields.
- GCN Circular #4294
D.K. Sahu, G. Pandey, P. Bama and N.K. Chakradhari (Indian Institute of
Astrophysics, Bangalore,India) communicate on behalf of a larger Indian
collaboration:
We observed the error box of the HETE trigger 3947 in Bessell R and I
filters with the 2-m Himalayan Chandra Telescope, Hanle, India, between
20:25 UT and 21:00 UT, 2005 October 21 (about 7 hours after the burst).
We could clearly detect the OT of GRB 051021 reported by Fox et al. (GCN
4120) with effective exposures of 600s (2x300s) in R and 900s (3x300s) in
I band. The preliminary magnitudes for the OT, estimated using the
calibration provided by Henden (GCN 4184) are as follows:
Filter Mean Mid-UT Magnitude
R 20:43 21.51+/-0.15
I 20.43 20.93+/-0.10
This message may be cited.
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