GRB 091208A
GCN Circular 10261
Subject
GRB 091208A, RIMOTS optical upper limits
Date
2009-12-08T13:40:03Z (16 years ago)
From
Kazuhiro Noda at Miyazaki U <kaz1206@astro.miyazaki-u.ac.jp>
K.Noda, K.Kono, E.Sonoda, N.Ohmori, H.hayasi,
A.Daikyuji, Y.Nisioka, M.Yamauchi
(University of Miyazaki)
We have observed the field covering the error circle of
GRB GRB091208A (Swift trigger 378554, GCN 10253, Hoversten et al.)
with the unfiltered CCD camera on the 30-cm telescope
at University of Miyazaki.
The observation was started 09:04:56 UT, about 19 min
after the Swift trigger time.
We have compared our data of 30 sec exposures
with the USNO-A2.0 catalog,
There is no new source at the reported position.
the upper limits are as follows:
--------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
--------------------------------------------------------------
09:04:56 09:05:26 1 15.8
09:04:56 09:48:39 33 17.3
---------------------------------------------------------------
GCN Circular 10264
Subject
GRB 091208A Swift-BAT refined analysis
Date
2009-12-08T15:58:56Z (16 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <james.r.cummings@nasa.gov>
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
E. A. Hoversten (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 091208A (trigger
#378554) (Hoversten, et al., GCN Circ. 10253). The BAT ground-
calculated position is RA, Dec = 0.295, 65.680 deg which is
RA(J2000) = 00h 01m 10.9s
Dec(J2000) = +65d 40' 47.7"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 88%.
The mask-weighted light curve shows a single FRED with some additional
structure on the decaying side. The tail appears to be quite long at
low energy, with emission detectable for up to 200 seconds after the
trigger. T90 (15-350 keV) is 29.1 +- 2.5 sec (estimated error including
systematics).
The time-averaged spectrum from T-0.3 to T+32.8 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
0.81 +- 0.10. The fluence in the 15-150 keV band is 1.5 +- 0.1 x 10^-06
erg/cm2. The 1-sec peak photon flux measured from T+0.15 sec in the
15-150 keV band is 1.8 +- 0.2 ph/cm2/sec. All the quoted errors are at
the 90% confidence level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/378554/BA/
GCN Circular 10270
Subject
GRB 091208A: Swift-XRT observations
Date
2009-12-08T22:24:53Z (16 years ago)
From
Claudio Pagani at PSU/Swift-XRT <pagani@astro.psu.edu>
C. Pagani, L. Vetere (PSU), P.A. Evans (U. Leicester), J. L. Racusin
(NASA/GSFC) and E. A. Hoversten (PSU) report on behalf of the Swift Team:
Swift/XRT observed the field of GRB 091208A (BAT trigger number 378554;
Hoversten et al. GCN Circ. 10253) from 3.1 ks to 3.3 ks after the BAT
trigger and again from 25 ks to 27 ks after the BAT trigger. The first
observation was delayed due to an observing constraint.
During the first observation no X-ray afterglow is detected inside the BAT
error circle (Barthelmy et al. GCN Circ. 10264) in 180 seconds of Photon
Counting data. The corresponding 3-sigma upper limit is 0.04 counts/s.
For comparison, the median XRT count rate for long GRB afterglows at 3 ks
after the BAT trigger is approximately 0.1 counts/s.
During the second observation no X-ray afterglow is detected inside the BAT
error circle in 694 seconds of PC data. The corresponding 3-sigma upper
limit is 0.01 counts/s. For comparison, the median XRT count rate for long
GRB afterglows at 25 ks after the BAT trigger is approximately 0.02
counts/s. Based on the count rates of the XRT afterglows observed during
the Swift mission the chance of detecting a long GRB with the XRT in a 1 ks
observation 25 ks after the BAT trigger is 61%.
This circular is an official product of the Swift-XRT team.
GCN Circular 10274
Subject
GRB091208A: Swift/UVOT refined analysis
Date
2009-12-09T13:43:27Z (16 years ago)
From
Massimiliano de Pasquale at MSSL-UCL <mdp@mssl.ucl.ac.uk>
M. De Pasquale (MSSL/UCL) and E. Hoversten (PSU) report on the behalf of
the Swift team:
Swift/UVOT observed the field of GRB091208A from 4.32 ks to 4.33 ks after
the BAT trigger in the v filter and then from 26.01 to 26.71 ks after the
trigger in u, v and white filters. No new source is detected in the BAT
error circle (Barthelmy et al., GCN Circ. 10264). We caution though that
a small fraction of BAT error circle is not covered by UVOT exposures.
3 sigma upper limits on magnitudes are as follows:
Filter T_start(s) T_stop(s) Exp(s) Mag
v 4318 4328 10 >17.4
v 26513 26717 200 >19.4
wh 26261 26507 243 >21.1
u 26008 26255 243 >20.1
The values quoted above are on the UVOT Photometric System
(Poole et al., 2008, MNRAS 383,627). They are not corrected for
the expected strong Galactic extinction, corresponding to a reddening
of E(B-V)=1.6.
GCN Circular 10276
Subject
Konus-Wind observation of GRB 091208A
Date
2009-12-10T16:47:11Z (16 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:
The long GRB 091208A (Swift-BAT trigger #378554:
Hoversten et al., GCN 10253; Barthelmy et al., GCN 10264)
triggered Konus-Wind at T0=31563.038s UT (08:46:03.038).
The burst light curve shows a smooth single-pulse structure
with a total duration of ~30 s. The Konus-Wind light
curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB091208_T31563/
As observed by Konus-Wind the burst
had a fluence of 6.2(+/-1.0)x10-6 erg/cm2,
and a 256-ms peak flux measured from T0-0.256s
of 1.3(+/-0.2)x10-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).
The time-integrated spectrum of the burst
(from T0 to T0+24.832 s) can be fitted
in the 20 keV - 2 MeV range by a power law
with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), with
alpha = +0.24(-0.5, +0.7),
and Ep = 314(-50, +70) keV (chi2 = 74/61 dof).
The spectrum of the most intense part of the burst
(measured from T0 to T0+8.448 s) is well fitted
in the 20 keV - 2 MeV range by a power law
with exponential cutoff model, for which
alpha = +0.13(-0.4, +0.55),
and Ep = 316(-44, +60) keV (chi2 = 47/61 dof).
All the quoted results are preliminary.
All the quoted errors are at the 90% confidence level.
GCN Circular 10277
Subject
GRB 091208A: GAO 150cm telescope Optical Observation
Date
2009-12-11T11:19:27Z (16 years ago)
From
Kenzo Kinugasa at Gunma Astro. Obs/Japan <kinugasa@astron.pref.gunma.jp>
K. Kinugasa, S. Honda, H. Takahashi, H. Taguchi, O. Hashimoto
(Gunma Astronomical Observatory) report:
The field of GRB 091208A (Hoversten et al. GCN 10253) was observed
with the 150 cm telescope of Gunma Astronomical Observatory. Starting
at 09:09:06 UT on Dec.8 ( 23.1 min after the trigger), both Rc and Ic
frames were acquired for sets of 5 x 0.5-min and 3 x 2-min exposures.
The limiting magnitude in combined image is estimated as Rc~20.5 and
Ic~20.0. We did not detect any new point source within the BAT error
circle down to the magnitudes of R~20.2 and I~19.5 relative to
USNO-B1.0 R2 and I magnitudes, respectively.
GCN Circular 10278
Subject
GRB 091208A: Suzaku WAM observation of the prompt emission
Date
2009-12-12T04:00:04Z (16 years ago)
From
Yusuke Nishioka at Miyazaki U. <yusuke613@astro.miyazaki-u.ac.jp>
Y. Nishioka, H. Hayashi, N. Ohmori, A. Daikyuji,E. Sonoda, K. Kono,
K. Noda, M. Yamauchi (Univ. of Miyazaki), T. Sugasahara, M. Tashiro,
Y. Terada, A. Endo, K. Onda, W. Iwakiri (Saitama U.), S. Sugita
(Nagoya U.), K. Yamaoka (Aoyama Gakuin U.), M. Ohno, M. Suzuki,
M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa, T. Tamagawa
(RIKEN), N. Vasquez (Tokyo Tech.), Y. Urata, H.M Lin (NCU),
Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.),
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Hong (Nihon U.),
on behalf of the Suzaku WAM team, report
The long GRB 091208A (Swift/BAT trigger #378554 ; Barthelmy et al.,
GCN 10264) triggered the Suzaku Wide-band All-sky Monitor (WAM) which
covers an energy range of 50 keV - 5 MeV at 2009-12-08 08:46:00.546 UT (=T0).
The observed light curve shows a single peak starting at T0 s,
ending at T0+10 s with a duration (T90) of about 6.6 seconds.
The fluence in 100 - 1000 keV was 4.85(-0.99, +0.65) x10^-6 erg/cm^2.
The 1-s peak flux measured from T0 s was 1.94 (-0.60, +0.61)
photons/cm^2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum from T0-0.5 s to
T0+10 s is well fitted by a single power-law with a photon index of
2.04 (-0.24, +0.28) (chi^2/d.o.f = 48.5/33).
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.
The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html