- GCN Circular #7295
K. Hurley and T. Cline on behalf of the Mars Odyssey, Konus,
and MESSENGER GRB teams,
J. Goldsten, on behalf of the MESSENGER GRNS GRB team,
W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on
behalf of the GRS-Odyssey GRB team,
I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks
on behalf of the Konus-Wind team,
D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger, W.
Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team,
K. Yamaoka, M. Ohno, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada,
T. Murakami, and K. Makishima on behalf of the Suzaku WAM team, report:
Mars Odyssey (GRS), MESSENGER (GRNS), Konus-Wind, RHESSI, and Suzaku-WAM
observed the long-duration GRB 080211 at about 26620 s UT (07:23:40).
The burst light curve shows a multipeaked structure with a duration of
~35 sec.
We have triangulated the burst to the following, preliminary 3-sigma
error box:
-----------------------------------------------
RA(2000) Dec(2000)
-----------------------------------------------
Center:
43.968 (02h 55m 52s) +60.035 (+60d 02' 07")
Corners:
43.862 (02h 55m 27s) +59.463 (+59d 27' 46")
43.747 (02h 54m 59s) +59.921 (+59d 55' 17")
44.081 (02h 56m 19s) +60.600 (+60d 35' 59")
44.191 (02h 56m 46s) +60.148 (+60d 08' 54")
-------------------------------------------------
The error box area is 409 sq. arcmin.
This error box may be improved.
Preliminary analysis of the Konus-Wind data yields
a burst fluence of ~6x10^-5 erg/cm2 (in the 20 keV - 2 MeV range),
and an Epeak of the time-integrated spectrum of ~360 keV.
Detailed spectral parameters will be reported later.
- GCN Circular #7309
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
and T. Cline on behalf of the Konus-Wind team report:
The long GRB 080211 (Hurley et al., GCN 7295)
triggered Konus-Wind at T0=26622.790 s UT (07:23:42.790).
As observed by Konus-Wind the burst
had a fluence of 4.66(-0.19, +0.20)x10^-5 erg/cm2,
and a 64-ms peak flux measured from T0+5.824 s
of (6.66 +/- 1.22)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+27.648 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 = -0.85 +/- 0.06
and Ep = 356(-22, +25) keV (chi2 = 70.6/62 dof).
The spectrum of the most intense part (from T0 to T0+5.888 s)
is well fitted (in the same range)
by a power law with exponential cutoff model
with alpha = -0.67 +/- 0.09
and Ep = 484(-40, +45) keV (chi2 = 53.2/62 dof).
Fitting by GRBM (Band) model yields:
the low-energy photon index is alpha = -0.61(-0.11, +0.13),
the high energy photon index beta = -2.62(-1.48, +0.40),
the peak energy Ep = 441(-61, +62) keV (chi2 = 50.0/61 dof).
The fluence of this part is (1.81 +/- 0.11)x10^-5 erg/cm2.
All the quoted errors are at the 90% confidence level.
The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB080211_T26622/
- GCN Circular #7312
A.P. Beardmore, K.L. Page (U. Leicester), H. Ziaeepour and M. de Pasquale
(MSSL/UCL) report on behalf of the Swift team:
At 2008-02-12 16:42:52UT the Swift-XRT started a TOO observation of the
IPN burst GRB 080211 (Hurley et al., GCN Circ. 7295), some 33.3 hours
after the trigger. The observation lasted only 656 s, at which point it
was terminated by the Swift discovery of GRB 080212 (Ziaeepour et al., GCN
Circ. 7296).
The photon counting mode image accumulated during this time shows no
evidence for a source in the XRT field of view, though only ~3/4 of the
IPN error box was sampled. The 3 sigma limiting count rate for a point
source in the XRT image is 0.009 count s^-1, which corresponds to a
0.3-10.0 keV flux limit of 5e-13 erg cm^-2 s^-1 (assuming a power-law
spectrum of photon index 2 absorbed by the Galactic column density of
7.8e21 cm^-2 in the direction of the burst).
The IPN field was also observed by the Swift-UVOT in the UW1 filter only,
for an exposure of 646 s. The 3 sigma upper limit is UW1 > 20.3. We note
that the background in this field is very noisy and the extinction is
highly variable throughout the field due to the presence of gas and dust
visible in DSS images.
This circular is an official product of the Swift-XRT and UVOT teams.
- GCN Circular #7315
M. Ohno, T. Uehara, T. Takahashi, Y. Fukazawa,
C. Kira, Y. Hanabata (Hiroshima U.),
K. Yamaoka, Y. E. Nakagawa, S. Sugita (Aoyama Gakuin U.),
M. Tashiro, Y. Terada, Y. Urata, A. Endo,
K. Onda, M. Suzuki, N. Kodaka, K. Morigami (Saitama U.),
T. Tamagawa (RIKEN),
T. Enoto, R. Miyawaki, K. Nakazawa, K. Makishima (Univ. of Tokyo),
E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara (Univ. of Miyazaki),
M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA),
S. Hong (Nihon U.),
on behalf of the Suzaku WAM team, report:
The bright, long, IPN localized GRB 080211 (Hurley et al., GCN 7295)
was detected by the the Suzaku Wide-band All-sky Monitor (WAM) which
covers an energy range of 50 keV - 5 MeV at 07:23:39 UT (=T0).
The observed light curve shows a multi-peaked structure, starting at
T0-10 s, ending at T0+25 s with a duration (T90) of about 25 seconds.
The fluence in 100 - 1000 keV was 2.8(+0.1,-0.1) x 10^-5 erg/cm^2.
The 1-s peak flux measured from T0+6 s was 5.5(+0.4,-0.6)
photons/cm^2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum from
T0-10s to T0+25s is well fitted by a power-law with exponential cutoff
model:
dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
alpha 1.1(+0.2,-0.2), and
Epeak 483(+66,-46) keV (chi^2/d.o.f. = 38/21).
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.
The light curves with 1-sec time resolution for this burst will be
appeared at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html
- GCN Circular #7331
M. Andreev (Terskol Branch of Institute of Astronomy) V. Petkov, A. Kurenya
(BNO INR RAS), A. Pozanenko (IKI) on behalf of larger GRB follow up
collaboration report:
We observed the GRB080211 (Hurley et al. GCN 7295, Golenetskii et al. GCN
7309) with Zeiss-600 of Mt.Terskol observatory on Feb. 12 between (UT)
17:10-17:21 in R-filter under poor weather conditions. Our observation
covered central part of the IPN error-box. Within IPN error-box (Hurley et
al. GCN 7295), we found one source not presented in any DSS2 plates.
Coordinates of the source are RA(J2000) = 02h55m50.9s, Dec.(J2000) = +60
05' 43.6". Photometry against of USNO-B1.0 is following
T0+ , Exposure, R_mag
(mid time)
1.41d 10x30 s 17.3
Further examination of XRT and UVOT observation (Beardmore et al. GCN 7312)
and additional observations are necessary to confirm the nature of the found
source.
Finding chart and combined image can be found in
http://grb.rssi.ru/GRB080211
The message may be cited.
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