GRB 110207A

O. M. Littlejohns (U Leicester), A. P. Beardmore (U Leicester),
S. Campana (INAF-OAB), V. D'Elia (ASDC), P. A. Evans (U Leicester),
J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC),
N. P. M. Kuin (UCL-MSSL), P. T. O'Brien (U Leicester),
C. Pagani (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), P. Romano (INAF-IASFPA),
A. Rowlinson (U Leicester), T. Sakamoto (NASA/UMBC),
B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU) and
R. L. C. Starling (U Leicester) report on behalf of the Swift Team:

At 11:17:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110207A (trigger=444912).  Swift could not slew to the
burst due to a Moon constraint. 
The BAT on-board calculated location is 
RA, Dec 12.542, -10.806 which is 
   RA(J2000) = 00h 50m 10s
   Dec(J2000) = -10d 48' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex multi-peaked
structure with a duration of about 40 sec.  The peak count rate
was ~8000 counts/sec (15-350 keV), at ~0.5 sec after the trigger. 

Due to a Moon observing constraint, Swift cannot slew to the BAT
position until 13:20 UT on 2011 February 08. There will thus be no XRT
or UVOT data for this trigger before this time. 

Burst Advocate for this burst is O. M. Littlejohns (oml2 AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk

K.Ivanov, O.Chuvalaev, V.Poleschuk, E.Konstantinov, V.Lenok, O.Gres,
S.Yazev, N.M.Budnev,
Irkutsk State University

E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina,
D.Kuvshinov, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov,
D.Zimnukhov, M. Kornilov, V.Shumkov, S.Shurpakov
Sternberg Astronomical Institute, Moscow State University

V.Krushinski, I.Zalozhnich, A. Popov
Ural State University, Kourovka

A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory

Two MASTER II  robotic telescopes (MASTER-Net: http://observ.pereplet.ru) 
located in  Amur-Blagoveschensk  and Tunka-Baykal was pointed to the 
GRB110207A 65 and 30 sec after GRB time correspondingly. On our first (10s exposure) 
set we haven`t found optical transient  within SWIFT-BAT error-box 
(Littlejohns et al., GCN Curc 11658).
Because GRB duration is 40 sec, the first images from Tunka is prompt.
The obdervations was done at high zenith distance (>80 degrees).

The 3-sigma upper limit has been about:
-----------------------------------------------------------------------
Start Time     mean time       Exp     Limit   Filter    Site 
after trigger  after trigger   (s)
-----------------------------------------------------------------------
    30s           35s           10      13.0     V+P\/   Tunka-Baykal
    65s           70s           10      14.1     V+P-|  Amur-Blagoveschensk
    65s          747s         1370      17.0     V+P-|  Amur-Blagoveschensk
   1700s        1790s          180      17.4      R       Tunka-Baykal

------------------------------------------------------------------------

P - is polarization.


The message may be cited.


mailto: lipunov@sai.msu.ru

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
O. M. Littlejohns (U Leicester), C. B. Markwardt (GSFC), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110207A (trigger #444912)
(Littlejohns, et al., GCN Circ. 11658
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 ).  The BAT ground-calculated position is
RA, Dec = 12.540, -10.790 deg, which is 
   RA(J2000)  =  00h 50m 09.5s 
   Dec(J2000) = -10d 47' 23.8" 
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows at least seven short peaks starting
at ~T-0.1 sec and ending at ~T+20 sec with a long decay extending out
to ~T+110 sec.  T90 (15-350 keV) is 80.3 +- 16.2 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-0.1 to T+108.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.30 +- 0.12.  The fluence in the 15-150 keV band is 1.6 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.11 sec in the 15-150 keV band
is 1.1 +- 0.1 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/444912/BA/

Klotz A. (CESR-OMP), Gendre B. (ASDC), Laas-Bourez M. (UWA)
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 110207A detected by SWIFT
(trigger 444912) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 6.62h after the GRB trigger
(beginning of the night). The elevation of the field
decreased from 25 degrees above horizon and weather
conditions were good.

We co-added a series of exposures.
No OT was detected :
t0+6.62h to t0+7.79h : R > 19.8

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon=121.8238 lat=-73.6747
and the galactic extinction in R band is 0.1 magnitude
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.

A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: 

"At 11:17:20.29 UT on 07 February 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110207A (trigger 318770242/ 110207470), which was
also 
detected by the Swift/BAT (Littlejohns et al. 2011, GCN 11658
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 )
The GBM on-ground location is consistent with the Swift position.
 
The angle from the Fermi LAT boresight is 72.8 degrees.

The GBM light curve shows a multi-peaked structure
with a duration (T90) of about 39 s (50-300 keV). 
The time-averaged spectrum from T0-0.256 s to T0+38.912 s is 
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.09 (+0.13/-0.12) and
the cutoff energy, parameterized as Epeak, is 450 (+290/-130) 
keV. The event fluence (10-1000 keV) in this time interval is 
(4.4 +/- 0.6)E-06 erg/cm^2. The 1.024-sec peak photon flux measured 
starting from T0+0.211 s in the 10-1000 keV band 
is 2.3 +/- 0.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."

P.A. Evans and O.M. Littlejohns (U. Leicester) report on behalf of the 
Swift team:

Swift observed the field of GRB 110207A (Littlejohns et al., GCN Circ. 
11658
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 ) for 5 ks from T0+99 ks to T0+112 ks; earlier observations were 
impossible due to the proximity of the GRB to the Moon. We find no X-ray 
sources in the BAT field of view, placing a 3-sigma upper limit on the 
afterglow brightness of 7.6e-14 erg/cm^2/sec during this interval 
(0.3-10 keV; assuming a typical GRB spectrum). Due to the proximity of 
the GRB to the Sun, no further observations are planned.

This circular is an official product of the Swift-XRT team.

P. Tsai, Y. Urata (NCU), T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa
(Hiroshima U.), N. Vasquez (Tokyo Tech.), K. Yamaoka (Aoyama Gakuin U.), 
S. Sugita (Nagoya U.), Y. Terada, M. Tashiro, S. Hong, W. Iwakiri, K. Takahara,
T. Yasuda (Saitama U.), M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA), 
Y. E. Nakagawa, T. Tamagawa,  M. Serino (RIKEN), N. Ohmori, A. Daikyuji, 
Y. Nishioka, M. Yamauchi (Univ. of Miyazaki), 
K. Nakazawa, K. Makishima (Univ. of Tokyo), 
on behalf of the Suzaku WAM team, report:

The GRB 110207A (Swift/BAT trigger #444912 ; Littlejohns et al., GCN 11658
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 ;
Palmer et al., GCN 11664
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 ) triggered the Suzaku Wide-band All-sky Monitor
(WAM) which covers an energy range of 50 keV - 5 MeV at 2011/02/07
11:17:20.05 UT (=T0).

The observed light curve shows a multi-peaked structure lasting from T0-0.2s
to T0+3.2s with a duration (T90) of about 2.9 seconds. The fluence in 100 -
1000 keV was 5.98 (+/-0.54) x 10^-7 erg/cm^2. The 1-s peak flux measured
from T0+0.32s was 0.27 (+/-0.06) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-0.2s to
T0+3.2s is well fitted by a single power-law with a photon index of 1.53
(-0.24, +0.29) (chi^2/d.o.f = 34.22/34).

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