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GRB 051211A

GCN Circular 4333

Subject
GRB 051211A and GRB051211B: BOOTES simultaneous observations
Date
2005-12-12T07:14:03Z (19 years ago)
Edited On
2024-11-18T10:08:20Z (7 months ago)
From
Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
M. Jelínek, A. J. Castro-Tirado, S. Vitek, A. de Ugarte Postigo 
(IAA-CSIC Granada),
P. Kubánek and R. Hudec (Astronomical Institute of the Academy of 
Sciences, Ondrejov), report:

The BOOTES instruments in South Spain responded to the two GRBs detected on
11 Nov 2005. The BOOTES-2 very wide field camera located at La Mayora 
(EELM-CSIC, Málaga) observed the region of the sky containing the 
HETE-2/SXC
error box for GRB 051211A (Atteia et al. GCN 4324) as part of the 
routinary observing schedule. A 30s exposure started at 2:50:00 UT (5s 
prior to the beginning of the 33s
long burst), i.e. overlaping with the single, hard gamma-ray peak 
detected by HETE-2. This image sets a R = 10 upper limit to the promt 
optical flash for GRB 051211A.

BOOTES-1 in El Arenosillo (INTA, Huelva), responded under non-optimal 
conditions to the GRB 051211B trigger (Mereghetti et al. GCNC 4327). A 
sequence of exposures started at 22:06:34 UT (50s after the GRB onset, 
30s after the GCN notice), i.e. overlaping for 30 s with the tail of the 
gamma-ray emission. We do no detect any transient optical emission in 
the 2' INTEGRAL error box and in particular at the position of the 
possible afterglow reported by Klotz et al. (GCNC 4328). We set a I > 14 
limit to any optical emission arising simultaneusly to the gamma-rays. 
We also notice moderate extinction in the line of sight: E(B-V) = 0.47 
from the Schlegel et al. dust maps (1998)."

This message can be quoted.

[GCN OPS NOTE(16dec05): Per author's request, the duplicate text was removed.]

GCN Circular 4339

Subject
GRB 051211A,optical observation
Date
2005-12-12T13:52:06Z (19 years ago)
From
Shouta Maeno at U.of Miyazaki <shouta@astro.miyazaki-u.ac.jp>
S.Maeno,E.Sonoda,M.Yamauchi
(University of Miyazaki)


"We have observed the field covering the error circle of
GRB 051211A (GCN 3979) with the unfiltered CCD camera 
on the 30-cm telescope at University of Miyazaki.
The observation was started 11:06:34 UT on Dec.11.
After co-adding a set of 18 images (11:06:34 UT - 11:28:23 UT)
of 30 sec exposures, we have compared with the USNO-A2.0 catalog.
Preliminary analysis shows there is no new source brighter than 
17.2 mag."

GCN Circular 4342

Subject
GRB 051211A: Swift/UVOT upper limits
Date
2005-12-12T15:48:34Z (19 years ago)
From
Alexander Blustin at MSSL-UCL <ajb@mssl.ucl.ac.uk>
A. J. Blustin (UCL-MSSL), G. Cusumano (INAF-IASF), J. Greiner (MPE),
D. Hinshaw (GSFC-SPSYS), N. Gehrels (GSFC) on behalf of the
Swift/UVOT team

The Swift/UVOT began observing the field of GRB 051211a at 15:50:04 UT
on 2005-12-11, 13 hours after the HETE trigger (Atteia et al., GCN 4324).
No potential optical/UV counterpart was found in co-added images in any
of the filters, within the reported 80 arcsec radius (90% confidence)
HETE error circle, down to the following 5-sigma magnitude upper limits 
(not corrected for extinction).

Filter   T_range(hours)  Exp(s)  5sigUL(mag)

V        14.9-15.1       886      19.4
B        13.5-13.7       738      20.2
U        13.3-16.7       1469     20.3
W1       13.0-16.5       1800     20.0
M2       11.9-15.3       1502     20.1
W2       14.6-14.9       900      20.1

GCN Circular 4344

Subject
GRB 051211a: RTT150 optical observations
Date
2005-12-12T23:40:20Z (19 years ago)
From
Irek Khamitov at TUG <irekk@tug.tug.tubitak.gov.tr>
R. Zhuchkov,  I. Bikmaev, N. Sakhibullin (KSU/AST)
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI)
I. Khamitov, Z. Aslan (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.),

report:

    The error radius of GRB 051211a (Atteia et al, GCN4324) was observed with
Russian-Turkish 1.5-m telescope (RTT150, Bakyrlytepe, TUBITAK National Observatory,
Turkey), starting at Dec. 11, 18:38UT, i.e. ~15.8 hours after the burst.
    Two frames (300s exposures in R and B bands) were taken. We did not detect
new sources to compare with DSS frames. Using USNO-B1 stars we estimate limiting
magnitude of our images as:

t-t0     Band   m_lim
(hour)          (mag)
----------------------
15.84	   R    20.60
15.99	   B    20.57

This message may be cited.

GCN Circular 4356

Subject
GRB051211A: possible optical candidate
Date
2005-12-15T14:13:31Z (19 years ago)
From
Cristiano Guidorzi at ARI,Liverpool JMU <crg@astro.livjm.ac.uk>
C. Guidorzi, A. Monfardini, I.A. Steele, A. Gomboc, C.G. Mundell,
C.J. Mottram, R.J. Smith, D. Bersier, A. Melandri, S. Kobayashi, 
D. Carter, M.F. Bode (Liverpool JMU), N. Tanvir (Hertfordshire)
report:


"The 2-m Faulkes Telescope North observed GRB051211A discovered by
HETE-2 (Atteia et al, GCN 4324) from 5.9 to 11.9 hours after the
burst.
So far, searches for afterglow have provided just upper limits in the
optical (de Ugarte Postigo et al. GCN 4325 & GCN 4335, Klotz et al. GCN
4329, Jelinek et al. GCN 4333, Maeno et al. GCN 4339, Blustin et al. GCN
4342, Zhuchkov et al. GCN 4344) as well as in the X-rays (Cusumano et al.
GCN 4326).
From the comparison of two 30-min stacked images, we found an object at
RA=06:56:09.0, DEC= +32:40:06.4 (J2000) showing some evidence of a fading
of 0.6 +- 0.3 mag (calibrated with USNOB stars of the field, with an
uncertainty of 0.4 mag affecting just the absolute values, but not the
relative ones). It lies 63 arcsec away from the HETE-2 centroid (given
with an error radius of 80 arcsec at 90% CL).

-----------------------------------------------------
Start Time	Filter	Exposure	Mag
since GRB
 
 6.3 hr		R	12x150s		21.15 +- 0.15
11.4 hr		R	12x150s		21.75 +- 0.20
-----------------------------------------------------
 
This candidate does not match any DSS source, although we notice a small
blur in the DSS IR that might be either a faint source or a background
fluctuation.
If we assume the fading is genuine, the average temporal decay
power-law index turns out to be around 1.0 +- 0.5.
However, a word of caution is required, as the source magnitude is
close to the limiting value affected by the moonlight.
 
An image of the OT candidate at both epochs is available at the following:
 
http://www.astro.livjm.ac.uk/~crg/GRB051211A_possible_OT_FTN.jpg
 
We encourage further observations."

GCN Circular 4359

Subject
GRB051211A (=H3979): Refined Analysis
Date
2005-12-16T18:58:27Z (19 years ago)
From
Carlo Graziani at U.Chicago <carlo@oddjob.uchicago.edu>
N. Kawai, G. Ricker, J-L. Atteia, 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, G. Pizzichini, and S. Gunasekera, 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:

We have analyzed the full FREGATE+WXM+SXC data for HETE trigger H3979
(GRB051211A).

Further ground analysis shows that the HETE SXC location for GRB051211A
reported in GCN 4324 is reliable. The SXC detected a soft transient source
in both the its X and Y cameras about 35 s after the trigger without the
assistance of the WXM. The location of this source is:

R.A. = 06h 56m 13s ; Dec. = 32d 40' 44" (J2000),

with a 90% confidence error radius of 80".

The WXM did not detect this soft transient, but it detected hard x-ray
emission coincident with the Fregate event. From this hard emission, WXM
obtained a solid X location matching the SXC transient. There are several
possible WXM Y locations, but one of them matches the SXC transient: the
random probability of this is only a few percent. This triple coincidence
in time and position gives us high confidence that the SXC transient is
associated with the Fregate trigger.

The 30-400 keV light curve has a fast rise (<0.1 s) and a slower
decay. The burst had a T90 duration of 4.8s in the 6-40 keV band, and of
4.2s in the 30-400 keV band.

The integrated spectrum is well-fit by a cutoff power-law function.  The
best-fit parameters are:

alpha = -0.67 --- 90% confidence interval is [-0.90 -0.38]
Epeak = 137 keV  --- 90% confidence interval is [106 , 200]

The 2-30 keV fluence is 1.6e-7 erg/cm2, while the 30-400 keV fluence is
9.6e-7 erg/cm2.

This burst had a hardness ratio (100-300 keV fluence)/(25-100 keV
fluence) of 1.18.  This, along with its 4.2 s T90, places it 
between the long duration bursts and the short duration bursts
in the hardness ratio-duration diagram.  We note, however, that if
lognormal functions are used to describe the long and short burst duration
distributions, this burst appears more likely to belong to the short
class. Thus, a search for a possible associated low redshift host galaxy
would be of interest.

A light curve, hardness ratio-duration diagram, and spectral information
for this event are provided at the following URL:

http://space.mit.edu/HETE/Bursts/GRB051211/

GCN Circular 4377

Subject
GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
Date
2005-12-21T22:25:49Z (19 years ago)
From
Don Lamb at U.Chicago <lamb@oddjob.uchicago.edu>
GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral Lag

J. Norris, 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, G. Pizzichini, and S. Gunasekera, 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:

We have performed an analysis of the spectral lag for GRB 051211A,
using FREGATE data in the 30-85 keV and 85-400 keV energy bands.  We
obtain a spectral lag of 0.000 +/- 0.024 seconds.  This result provides
strong additional evidence that GRB 051211A is a short burst [Norris,
J. P., Scargle, J. D., and Bonnell, J. T.  2001, in Gamma-Ray Bursts in
the Afterglow Era, ed. E. Costa, F. Frontera, and J. Hjorth (Berlin:
Springer), p. 40; and Norris, J. P., and Bonnell, J. T. 2005, ApJ,
submitted (see, e.g., Figure 3)].

GCN Circular 4623

Subject
GRB 051211A: MDM Observations
Date
2006-01-31T00:15:50Z (19 years ago)
From
Jules Halpern at Columbia U. <jules@astro.columbia.edu>
J. P. Halpern (Columbia U.) & N. Mirabal (U. Michigan) report on behalf 
of the MDM Observatory GRB follow-up team:

"Guidorzi et al. (GCN 4356) reported a possible optical afterglow 
for the HETE-2 burst GRB 051211A (Atteia et al., GCN 4324; Kawai
et al., GCN 4359) that faded from R = 21.15+/-0.15 to R = 21.75+/-0.20
between 6.3 hr and 11.4 hr after the burst.  As they noted that there
is a hint of its presence on the I-band POSS plate, and in view of
the likelihood that this was a short burst (Norris et al., GCN 4377),
it is interesting to follow up on this candidate afterglow to determine
if it is hosted by a relatively nearby galaxy.  We observed and detected
the same object on 2005 Dec. 25 with the MDM 2.4m telescope and RETROCAM
imager in five 300 s exposures in the SDSS r' filter.  Its position is
R.A. = 06:56:09.00, Decl. = +32:40:06.3 (J2000), the same as previously
determined.  Calibration with Landolt stars yields R = 21.72+/-0.05
(statistical), with an additional systematic uncertainty of 0.1 likely.
This is consistent with the later measurement of Guidorzi et al.,
but not their earlier one.  The object is not resolved in our images
at the seeing of 0.95", which argues against a host interpretation.
We observed it again in the I band with the MDM 8K imager on 2006 Jan. 29.
Three 600 s exposures were obtained in seeing of 0.85".  Although the
latter images are uncalibrated, the object appears not to have faded,
is still at the limit of the I-band POSS plate, and is still unresolved.
Therefore, we conclude that it is most likely a star and not the
afterglow of GRB 051211A.

The MDM I-band image is posted at 

http://www.astro.columbia.edu/~jules/grb/051211a/

This message may be cited"

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