- GCN/BACODINE POSITION NOTICE
TITLE: GCN/HETE BURST POSITION NOTICE
NOTICE_DATE: Fri 28 Oct 05 13:36:06 UT
NOTICE_TYPE: HETE S/C_Alert
TRIGGER_NUM: 3951, Seq_Num: 1
GRB_DATE: 13671 TJD; 301 DOY; 05/10/28
GRB_TIME: 48961.48 SOD {13:36:01.48} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 182 [cnts/s] on a 1.300 [sec] timescale
SC_LONG: 170 [deg East]
SUN_POSTN: 212.94d {+14h 11m 46s} -13.27d {-13d 15' 56"}
MOON_POSTN: 165.86d {+11h 03m 26s} +8.98d {+08d 58' 41"}
MOON_ILLUM: 19 [%]
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 28 Oct 05 15:39:10 UT
NOTICE_TYPE: HETE Ground Analysis
TRIGGER_NUM: 3951, Seq_Num: 3
GRB_DATE: 13671 TJD; 301 DOY; 05/10/28
GRB_TIME: 48961.47 SOD {13:36:01.47} UT
TRIGGER_SOURCE: Trigger on the 25-400 keV band.
GAMMA_RATE: 182 [cnts/s] on a 1.300 [sec] timescale
SC_-Z_RA: 34 [deg]
SC_-Z_DEC: 14 [deg]
SC_LONG: 170 [deg East]
WXM_CNTR_RA: 27.163d {+01h 48m 39s} (J2000),
27.254d {+01h 49m 01s} (current),
26.385d {+01h 45m 32s} (1950)
WXM_CNTR_DEC: +47.808d {+47d 48' 31"} (J2000),
+47.837d {+47d 50' 14"} (current),
+47.560d {+47d 33' 36"} (1950)
WXM_CORNER1: 27.5820 47.6850 [deg]
WXM_CORNER2: 26.7550 47.6340 [deg]
WXM_CORNER3: 26.7430 47.9320 [deg]
WXM_CORNER4: 27.5730 47.9829 [deg]
WXM_MAX_SIZE: 39.05 [arcmin] diameter
WXM_LOC_SN: 10 sig/noise (pt src in image)
WXM_IMAGE_SN: X= 5.4 Y= 5.4 [sig/noise]
WXM_LC_SN: X= 9.9 Y= 3.0 [sig/noise]
SUN_POSTN: 212.94d {+14h 11m 46s} -13.27d {-13d 15' 56"}
SUN_DIST: 145.10 [deg]
MOON_POSTN: 165.86d {+11h 03m 26s} +8.98d {+08d 58' 41"}
MOON_DIST: 112.44 [deg]
MOON_ILLUM: 19 [%]
GAL_COORDS: 132.78,-13.97 [deg] galactic lon,lat of the burst
ECL_COORDS: 43.95,33.90 [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.
- red DSS finding chart
ps-file
- GCN Circular #4171
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 HETE GRB051028.6 .
An automated response took first image 2005-10-28 16:59:56 UT,
03h 23 m after the GRB time.
The unfiltered image is calibrateds relative to USNO A2.0 (0.8 R + 0.2 B).
Reduction is continued.
The robot not find OT-candidate in error box brighter then 17.0.
This work is supported by RFFI 04-02-16411 grant.
This message can be cited.
Mailto: lipunov@sai.msu.ru
- GCN Circular #4172
GRB 051028 (=H3951): A GRB localized by HETE
K. Hurley, 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-F Olive, and J-P Dezalay, on behalf of the HETE FREGATE
Team;
report:
At 13:36:01.47 UTC (48961.47 s UT) on 28 Oct 2005, the HETE FREGATE and
WXM instruments detected event H3951, a bright GRB.
The burst triggered FREGATE in the 30-400 keV energy band. The burst
duration (T90) was 16 seconds in both the 30-400 keV band and the
7-30 keV band.
Ground analysis of the WXM data produces a 90% confidence error region
measuring 33 x 18 arcminutes with corners at the following coordinates:
RA = 01h 50m 19.6s, Dec = +47d 41m 06s
RA = 01h 47m 01.1s, Dec = +47d 38m 02s
RA = 01h 46m 58.3s, Dec = +47d 55m 55s
RA = 01h 50m 17.5s, Dec = +47d 58m 58s
The 30-400 keV fluence of GRB 051028 is 6e-6 erg/cm2; the 2-30 keV
fluences is 6e-7 erg/cm2. The hardness ratio allows us to classify
this burst as a classical GRB.
Further information will be available at
http://space.mit.edu/HETE/Bursts/GRB051028
- GCN Circular #4173
V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski, E.Gorbovskoy,
A.Krylov, G.Borisov, A.Sankovich, G. Antipov, V.Vladimirov
Sternberg Astronomical Institute, Moscow Union 'Optic' MASTER robotic system
(http://observ.pereplet.ru)
responded to HETE GRB051028.6 (GCN 4172).
An automated response took first image 2005-10-28 16:59:56 UT,
03h 23 m after the GRB time (GCN4171).
The unfiltered image is calibrated relative to USNO A2.0 (0.8 R + 0.2 B).
We not find OT-candidate in error box brighter then 17.9 on the
summ of 9 images between 17 32 40 - 18 03 03 UT.
Mean time is 17 48 09 ( 4 h 12 min after GRB Time).
The JPG-image of the summ will be available at
http://observ.pereplet.ru/images/GRB050828/1.jpg (In error circ you can
see candidates which we recognised with 2MASS ).
The reduction is continuing.
This work is supported by RFFI 04-02-16411 grant.
This message can be cited.
Mailto: lipunov@sai.msu.ru
- GCN Circular #4174
J. Racusin (PSU), K. Page (U. Leicester), J. Kennea, D. Morris, C. Pagani,
D. Burrows (PSU), N. Gehrels (GSFC) on behalf of the Swift XRT team:
The Swift XRT began observing the field of the HETE discovered GRB 051028
(Hurley et al., GCN 4172) at 20:44:08 UT, approximately 7.1 hours after
the trigger. We have analyzed the first 3 orbits of data and we detect an
uncatalogued fading X-ray source at the following coordinates:
RA(J2000): 01 48 15.1
Dec(J2000): +47 45 12.5
with an estimated uncertainty of 6 arcseconds (90% containment), including
corrections for the XRT boresight offset. This position is 5.2 arcminutes
from the center of the HETE error box reported in Hurley et al. (GCN
4172).
Note that the HETE error box quoted in Hurley et al. (GCN4172) actually
extends beyond the field of view of the XRT. However, the source
mentioned above is the only bright source in the field and is decaying.
Therefore, it is likely the afterglow of GRB051028.
- GCN Circular #4175
M. Jelinek, S.B.Pandey, S.S.Guziy, A.J.Castro-Tirado, J.
Gorosabel, A. de Ugarte Postigo, and S. Vitek (IAA CSIC
Granada, Spain) and
J.T.A. De Jong, (Max Planck Intitut fuer Astronomie,
Heidelberg, Germany)
report
We have observed the complete errorbox of HETE trigger 3951
(Hurley et al, GCN 4172) with the prime focus camera of
William Herschel Telescope at La Palma starting 21:42UT (ie.
~7h after the GRB).
We detect an object within the XRT errorbox (Racusin et al,
GCN 4174) at coordinates RA 01:48:15.01 Dec 47:45:09.2 (+/-
1.0", J2000), with a rough magnitude R=22, which is not
present in DSS. Further observations will be needed to confirm
whether this is indeed the optical afrterglow of GRB051028.
The image limit is ~24.2.
This message may be cited.
- GCN Circular #4176
S.B.Pandey, M. Jelinek, S.S.Guziy, A.J.Castro-Tirado, J.
Gorosabel, A. de Ugarte Postigo, and S. Vitek (IAA CSIC
Granada, Spain) and
J.T.A. De Jong, (Max Planck Intitut fuer Astronomie,
Heidelberg, Germany)
report:
Further monitoring of the afterglow candidate (Jelinek et al.
7145) using 4.2 meter William Herschel Telescope confirms the
decay nature of the source, suggesting the source is really the
optical afterglow of GRB 051028.
Our observation 15 h after the burst show that the OT magnitude
has decayed considerably and it is around 23 in R band.
We have posted the searchmap to the following website:
http://lascaux.asu.cas.cz/mates/grb051028.gif
This message may be cited.
- GCN Circular #4177
A. J. Blustin, M. J. Page, M. De Pasquale, S. R. Oates (UCL-MSSL),
K. Hurley (Berkeley), M. Chester (PSU), N. Gehrels (GSFC) report
on behalf of the Swift/UVOT team:
The Swift/UVOT began observing the field of GRB 051028 at
20:44:06 UT on 2005-10-28, 7.1 hours after the HETE trigger (Hurley
et al. GCN 4172). No new source (with respect to the DSS) was
detected at the XRT (Racusin et al. GCN 4174) or WHT (Jelinek et al.
GCN 4175, Pandey et al. GCN 4176) positions in summed images from
the four UVOT filters used down to the following 3-sigma upper
limits:
Filter T_range(hours) Exp(sec) 3sigUL
V 7.4-10.3 1441 20.2
W1 8.7-10.8 1700 21.1
M2 8.5-10.5 1763 21.4
W2 7.1-9.1 1456 21.4
We note that this burst is at low galactic latitude, with an
E(B-V) of 0.21 and A_v of 0.71 mag.
- GCN Circular #4178
P. Ferrero, D. A. Kann, S. Klose, and C. Hoegner, Thueringer
Landessternwarte Tautenburg,
report:
We observed the entire error box of GRB 051028 (HETE trigger 3951;
Hurley et al. 2005, GCN 4172) with the 1.34-m Tautenburg Schmidt
telescope equipped with the prime focus CCD camera on October 28,
2005. Sky conditions were very good.
We obtained 6x180s I-band images (mean time Oct. 28.716 UT), 6x180s
R-band images (mean time Oct. 28.739 UT), 6x180s V-band images (mean
time Oct. 28.77 UT) and a final set of 60x180s I-band images (mean
time Oct. 28.898 UT), corresponding to 3.58, 4.12, 4.88 and 7.94
hours after the burst, respectively.
In our stacked images we clearly detect the afterglow candidate
(Jelinek et al. 2005, GCN 4175; Pandey et al. 2005, GCN 4176) in all
bands.
A preliminary estimation of the afterglow magnitude on the first six
co-added I-band images gives I~19, in comparison with the USNOB.1
star 1377-0047752 at R.A. (J2000)=01h 48m 15.974s and Decl.=+47d 45' 02.34"
(Monet et al. 2003).
Further analysis is in progress.
This message may be quoted.
- GCN Circular #4179
Autumn Homewood, Kiran Garimella, Stephen Fuller and Dieter H. Hartmann,
report on behalf of the Clemson GRB Follow-Up Team, and the FUN
Collaboration:
We imaged the central 8x12 arcmin field of the HETE error box for trigger
3951 (GCN 4172) with the SARA 0.9-m at Kitt Peak. We do not detect the OT
reported by Jelinek, et al (GCN 4175). We began observations under cloudy
conditions at UT 2005 Oct 29 02:27:55, approximately 11 hours after the
burst, and stacked 18 R-band exposures of 180 seconds each. We derive a
limiting magnitude of R=20.4 +/-0.3 mag. Images were calibrated using the
USNO B1.0 Catalog. This message may be cited.
The Clemson GRB Follow-Up Website can be found at:
http://people.clemson.edu/~kgarime/burst
The SARA website is located at:
http://www.saraobservatory.org
- GCN Circular #4182
V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski, E.Gorbovskoy,
A.Krylov, G.Borisov, A.Sankovich, G. Antipov, V.Vladimirov
Sternberg Astronomical Institute, Moscow Union 'Optic'
MASTER robotic system (http://observ.pereplet.ru) responded to
HETE GRB051028 (GCN 4172) at very nice Moscow weather.
Unfortunately, the remoute observations was delayted due to manage computer
problems. Now we find new earlier images. First image was at 2005-10-28
16:23:14 (not at 16:59:56 UT as we noted in GCN4171, GCN4173) i.e. 2h 46min
after GRB time.
The unfiltered image is calibrated relative to USNO A2.0 (0.8 R + 0.2 B).
Final results: the uper limits on OT (M. Jelinek et al. GCN4175) are
UT (start) T-T_GRB TotExpTime 3sigma limit
16:23:14 02h 46 m 45 s 17.9
16:59:56 03h 23 m 45 s 17.5
17:32:40 04h 12 m 360 s 18.3
20:01:04 06h 41 m 1050 s 19.6
21:46:43 08h 26 m 1200 s 19.4
This work is supported by RFFI 04-02-16411 grant.
This message can be cited.
Mailto: lipunov@sai.msu.ru
- GCN Circular #4183
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and
T. Cline on behalf of the Konus-Wind team report:
The GRB 051028 (HETE trigger #3951; Hurley et al., GCN 4172)
triggered Konus-Wind at T0=48967.159 s UT (13:36:07.159)
The time-integrated spectrum of the GRB (from T0 to T0+8.448 sec)
is well fitted (in the 20 keV - 2 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha) * exp(-E/E0)
with alpha = 0.73 (-0.26, +0.22)
and E0 = 236 (-68, +110) keV (chi^2 = 61/62 dof).
The peak energy Ep = 298 (-50, +73) keV.
It can also be fitted by GRBM (Band) model for which:
the low-energy photon index is alpha = -0.47 (-0.37, +0.57),
the high energy photon index beta < -1.97,
the break energy E0 = 150 (-69, +118) keV.
As observed by Konus-Wind the burst had a duration ~12 sec,
fluence 6.78(-1.08, +0.61)x10^-6 erg/cm2 and
peak flux on 256-ms time scale 1.29(-0.24, +0.15)x10^-6 erg/cm2/sec
(both in the 20 keV - 2 MeV energy range).
All the quoted errors are at the 90% confidence level.
- 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 #4205
K.L. Page, M.R. Goad (U. Leicester), D.N. Burrows, J. Racusin (PSU), S.
Oates (MSSL), M. Ajello (MPE) and M. Trippico (GSFC-SSAI) report on behalf
of the Swift XRT team:
We have analysed 38 ks of XRT observations of the HETE burst GRB051028
(trigger number H3951; GCN 4172, Hurley et al.), between approximately 7.1
and 178 hours after the trigger. As reported in GCN 4174 (Racusin et al.),
there is an uncatalogued, fading X-ray source within the HETE error
circle. The refined coordinates for this X-ray afterglow are:
RA(J2000): 01 48 15.1
Dec(J2000): +47 45 12.9
with an estimated uncertainty of 3.8 arcsec (90% containment) and
including the latest XRT boresight correction. The position is 0.6 arcsec
from that given by Racusin et al. (GCN 4174) and 3.9 arcsec from the
optical afterglow detected by the WHT (GCNs 4175, Jelinek et al., and
4176, Pandey et al.)
The X-ray light-curve shows a simple power-law decay with a slope of 1.25
+0.25/-0.16. The spectrum of the full 38 ks of data can also be modelled
with a power-law, with photon index, Gamma = 1.74 +/- 0.21. There is no
evidence for an absorbing column higher than the Galactic value of 1.2e21
cm^-2.
At 7.1 hours, the 0.3-10 keV observed (unabsorbed) flux was ~1.8e-12
(2.2e-12) erg cm^-2 s^-1. At 178 hours, the afterglow had faded to an
observed (unabsorbed) flux level of 2.3e-14 (2.8e-14) erg cm^-2 s^-1.
- GCN Circular #4278
D.K. Sahu, S. Srividya and S. Vanniarajan (Indian Institute of
Astrophysics, Bangalore,India) communicate on behalf of a larger Indian
collaboration:
We observed the central 10x10 arcmin region of the error circle of
the HETE trigger 3951 in Bessell R and I filters with the 2-m
Himalayan Chandra Telescope, Hanle, India, starting from 16:15 UT,
2005 October 28 (about 2.7 hours after the burst).
We could clearly detect the OT of GRB 051028 reported by Jelinek et al.
(GCN 4175). The preliminary R band magnitude for the OT, estimated
using the calibration provided by Henden (GCN 4184), is R=20.77+/-0.10
at 16:18 UT. The OT decayed by ~1.3 mag in R band in 1.5 hours. Further
analysis is in progress.
This message may be cited.
- GCN Circular #5190
K. Masuno, Y. Urata, M. Tashiro, K. Abe, K. Onda, N. Kodaka (Saitama-U),
F. Usui (ISAS/JAXA), M. Kuwahara (TUS/RIKEN), T. Tamagawa (RIKEN) report:
"We observed the error region of GRB 051028 (Hurley et al. GCN 4172)
with the very wide-field camera WIDGET located at Akeno, Japan. WIDGET
monitored the region with repeat of unfiltered 5-second exposures
between 16.0 min and 11.2 min before the burst. We did not find any
optical emission from the afterglow position (Jelinek et al. GCN
4175). The 1-sigma limiting magnitude of each frame derived by the
Tycho-2 catalog was around V=10.3 magnitudes."
This message may be cited.
- astro-ph/0609654 from 24 Sep 2006
Castro: GRB 051028: an intrinsically faint GRB at high redshift?
We present multiwavelength observations of the gamma-ray burst GRB 051028
detected by HETE-2 in order to derive its afterglow emission parameters and to
determine the reason for its optical faintness when compared to other events.
Observations were taken in the optical (2.0m Himalayan Chandra Telescope, 1.34m
Tautenburg, 4.2m William Herschel Telescope) and in X-rays (Swift/XRT) between
2.7 hours and 10 days after the onset of the event. The data can be interpreted
by collimated emission in a jet with a typical value of $p$ = 2.4 which is
moving in an homogeneous interstellar medium and with a cooling frequency
nu_{c} still above the X-rays at 0.5 days after the burst onset. GRB 051028 can
be classified as a ``gray'' or ``potentially dark'' GRB. On the basis of the
combined optical and Swift/XRT data, we conclude that the reason for the
optical dimness is not extra absorption in the host galaxy, but rather the GRB
taking place at high-redshift.We also notice the very striking similarity with
the optical lightcurve of GRB 050730, a burst with a spectroscopic redshift of
3.967, although GRB 051028 is about 3 mag fainter. We suggest that the bump
could be explained by multiple energy injection episodes and that the burst is
intrinsically faint when compared to the average afterglows detected since
1997. The non-detection of the host galaxy down to R = 25.1 is also consistent
with the burst arising at high redshift, compatible with the published pseudo-z
of 3.7 +/- 1.8.
- 0706.0561 from 4 Jun 2007
Urata: A multi band study of the optically dark GRB 051028
Abstract: Observations were made of the optical afterglow of GRB 051028 with the Lulin
observatory's 1.0 m telescope and the WIDGET robotic telescope system. R band
photometric data points were obtained on 2005 October 28 (UT), or 0.095-0.180
days after the burst. There is a possible plateau in the optical light curve
around 0.1 days after the burst; the light curve resembles optically bright
afterglows (e.g. GRB 041006, GRB 050319, GRB060605) in shape of the light curve
but not in brightness. The brightness of the GRB 051028 afterglow is 3
magnitudes fainter than that of one of the dark events, GRB 020124. Optically
dark GRBs have been attributed to dust extinction within the host galaxy or
high redshift. However, the spectrum analysis of the X-rays implies that there
is no significant absorption by the host galaxy. Furthermore, according to the
model theoretical calculation of the Ly$\alpha$ absorption to find the limit of
GRB 051028's redshift, the expected $R$ band absorption is not high enough to
explain the darkness of the afterglow. While the present results disfavor
either the high-redshift hypothesis or the high extinction scenario for
optically dark bursts, they are consistent with the possibility that the
brightness of the optical afterglow, intrinsically dark.
Previous IAU Circulars 
