GRB 111225A
GCN Circular 16079
Subject
GRB 111225A: Archeological redshift of the Christmas Burst 2011 from GTC
Date
2014-04-04T11:37:47Z (12 years ago)
From
Christina Thoene at IAA-CSIC <christina.thoene@gmail.com>
C.C. Thoene (IAA-CSIC) and A. de Ugarte Postigo (IAA-CSIC, DARK/NBI)
report on behalf of a larger collaboration:
We observed the Christmas burst of 2011, GRB 111225A (Siegel et al. GCN
12720), with the 10.4m GTC telescope+OSIRIS on December 25, 2011 at a mean
time 23:27 UT, 19.61 hrs after the burst. The observations consisted of
2x1800 s exposure with grism R1000B, covering the wavelength range from
3700 to 7870A with a resolution of around R=1000.
Initial analysis of the spectrum revealed continuum emission over the
complete range but no significant features neither in absorption nor
emission. However, a more careful analysis recently performed on the data
with an improved pipeline revealed faint emission features of [OII], H-beta
and [OIII], and marginal absorption of CaII at a common redshift of
z=0.297, which we therefore identify as the redshift of the GRB.
We apologise for the late notification. Better late than never.
GCN Circular 12893
Subject
GRB 111225A: optical observations
Date
2012-01-21T22:04:47Z (14 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A.Volnova (SAI MSU), E. Klunko (ISTP), M. Andreev, A. Sergeev (Terskol
Branch of INASAN), A. Pozanenko (IKI) on behalf of larger GRB follow up
collaboration report:
We observed the field of GRB 111225A (Siegel et al., GCN 12720) with
AZT-33IK telescope of Sayan observatory (Mondy) on Dec. 25 between (UT)
17:37:41 - 18:25:58 in R filter under mean seeing (FWHM) of about 2.0".
We also observed the field with Zeiss-2000 telescope of Mt. Terskol
observatory on Dec. 26 between (UT) 17:37:23-18:46:37 in BRI filters under
poor seeing (FWHM) of about 4.4". On stacked images of both epochs we did
not find an optical counterpart (Siegel et al., GCN 12720; Klotz et al.,
GCN 12722; Adria et al., GCN 12723; Wren et al., GCN 12803).
The photometry is based on the USNO-B1.0 star 1415-0025726 (J2000)
00:52:35.11 +51:33:58.9, assuming B = 17.56, R =16.50, I = 16.20:
T0+, Filter, Exposure, OT, UL(3 sigma), Telescope
(mid, d) (s)
0.63278 R 24 x 120 n/d 22.5 AZT-33IK
1.58789 B 10 x 90 n/d 22.0 Zeiss-2000
1.60285 R 10 x 90 n/d 21.5 Zeiss-2000
1.61677 I 10 x 90 n/d 20.5 Zeiss-2000
Upper limits above are consistent with upper limits of R~22.5 reported by
Sonbas et al. (GCN 12740) and observations of the afterglow at R ~ 23.2 on ~
1day after burst trigger (Cenko et al., GCN 12733). Taking into account the
positive detection of the afterglow on 3.7590 days at R~22.5 (Rumyantsev et
al., GCN 12793) one can suggest a strong rebrightening of the afterglow
which is a rare case of late afterglow (3.7590 days) of an apparently
nearby burst (cf. UVOT optical detection in uvw2 filter (Siegel, GCN
12735).
GCN Circular 12808
Subject
GRB 111225A, the review of the sky area in plate archives
Date
2012-01-05T13:04:16Z (14 years ago)
From
Valentyna Golovnya at Main Astro Obs,Kyiv <golov_v@ukr.ne>
V.V.Golovnya, L.M.Kizyun, L.K.Pakuliak (Main Astro Obs, Kyiv)
report:
We have undertaken the review of the sky area in vicinity of
GRB 111225A (M. H. Siegel, GCN Circ.12735) on astronegatives,
collected in Ukrainian NAS Main astronomical observatory plate
archive (1976-1996). All the plates with the possible object
appearance are digitized using Microtek ScanMaker 9800XL TMA
and Epson Expression 10000XL flatbed scanners and have been
placed into Golosiiv Plate Archive database DBGPA with open
access to them.
The list of plates is given in the table:
YYYYMMDD/TimeUT --Plates-- Exp. LimMag Star USNOA2
19831109/192323 GUA040C000250A 13.5 15.70 1350-00882390
19831109/194519 GUA040C000251A 13.0 15.20 1350-00878189
19840828/001418 GUA040C000469A 16.0 15.70 1350-00882390
19841019/211508 GUA040C000511A 15.9 15.70 1350-00882390
19841020/205803 GUA040C000525A 16.0 14.85 1350-00882046
Plates: �the plates archive identifier of DWA (D/F=400/2000,
GUA040C M=103"/mm) of the Ukrainian NAS Main Astro obs.
(Marsden's number - 83) the plate number [1].
Exp. - Duration of the maximum exposure (minutes).
LimMag - Limited V mag, derived in the 20 minutes area around
the location given in GCN Circ.12735:
RA (J2000) = 00:52:37.22, Dec (J2000) = +51:34:19.5
Star USNOA2 - Comparison star.
The preview images of 5 areas together with
the 20x20 min.of arc area from SkyMap can be found in
http://gua.db.ukr-vo.org/img/grb/111225A/index.html
The images with full resolution are available via e-mail on
demand.
References:
1.L.Pakuliak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0),
http://gua.db.ukr-vo.org
GCN Circular 12803
Subject
GRB111225A: RAPTOR Early Detection of the Optical Counterpart
Date
2012-01-04T01:15:03Z (14 years ago)
From
James Wren at LANL <jwren@nis.lanl.gov>
J. Wren, W. T. Vestrand, P. Wozniak, and H. Davis
of Los Alamos National Laboratory report:
The RAPTOR network of robotic optical telescopes responded to Swift trigger
510341 (GRB 111225A, Siegel et al., GCN 12720). Unfiltered observations of
the source location began at 03:51:27.2 UTC, 49.4 seconds after the BAT
trigger time. The initial short exposures during the first two mintues of our
response sequence do not clearly show the counterpart. However, stacking
those images, 8 5-second exposures taken between 03:51:37.6 UTC and
03:52.46.0 UTC, gives a 5-sigma detection at counterpart location
(Klotz et al., GCN 12722, and Updike et al., GCN 12723). Based on
comparison to the USNO-B1 R-band, the measured brightness is R~18.7 +\- 0.3
at a t-mid of 03:52:12 UTC, 94 seconds after the Swift BAT trigger.
GCN Circular 12793
Subject
GRB 111225A: optical observations in CrAO
Date
2011-12-31T15:26:40Z (14 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB
follow-up collaboration:
We observed the field of GRB 111125A (Siegel et al. GCN 12720) with Shajn
telescope of CrAO observatory on Dec. 28 between (UT) 21:28: and 22:38 under
a mean seeing of 1.7 arsces. We took several frames with exposure of 60 s in
R-band. We clearly detect afterglow of GRB 111225A (Klotz et al. GCN 12722)
on a stacked image. A photometry is based on the USNO B1.0 star 1415-0025726
(00 52 35.11 +51 33 58.9, J2000) assuming R=16.50.
T_start UT T0+ Filter, Exposure, OT, uplim (3 sigma)
(mid, d) (s)
21:28:14 3.7590 R 62x60 22.51 +/- 0.10 24.0
GCN Circular 12772
Subject
GRB 111225A: Lightbuckets Optical Observations
Date
2011-12-29T20:12:26Z (14 years ago)
From
Tilan Ukwatta at MSU <tilan.ukwatta@gmail.com>
T. N. Ukwatta (MSU), E. Sonbas (GSFC/Adiyaman Univ.),
T. Sakamoto (GSFC/UMBC), N. Gehrels (GSFC), J. Linnemann (MSU),
K. Tollefson (MSU), and U. Abeysekara (MSU)
We observed the field of Swift GRB 111225A
(Siegel et al., GCN 12720) with the Lightbuckets 0.43m
rental telescope LB-0002 in South Alpen, France. Ten 60 s
observations were carried out in the R filter starting
2011-12-25 at 17:01:47 UT (~ 47 ks after the GRB trigger).
We do not detect the optical afterglow both in the individual
images and in the stacked image inside the XRT location. Our
upper-limit based on the stacked observation (using the
USNO-B1 catalog) is given below.
Time after trigger Exposure (s) Filter Magnitude
13.2 hours 10 x 60 R > 19.7
GCN Circular 12740
Subject
GRB 111225A, optical observations
Date
2011-12-28T18:26:56Z (14 years ago)
From
Eda Sonbas at NASA/GSFC <edasonbas@gmail.com>
TITLE: T100 observations of GRB 111225A
Sonbas, E.(Adiyaman Univ.), Guver, T. (Sabanci Univ.), Gogus, E. (Sabanci
Univ.),
Uysal, O. (Akdeniz Univ.), Sahin T. (Akdeniz Univ.), Eker, Z. (TUG), T.
Ozisik (TUG) on behalf of a larger collaboration.
We observed the field of GRB 111225A (Siegel et al., GCN #12720) with the
1.0 meter T100 telescope (TUBITAK National
Observatory, Antalya - Turkey), starting on December 25, 21:14 UT (~ 17
hours after the trigger). We obtained
3 x 60 s + 2 x 300 s exposures with R and B filters under moderate weather
conditions (seeing 1.8").
We do not detect an optical afterglow at the enhanced XRT error circle
reported by Evans et al., GCN #12724
in the combined R and B band images. We determine the following 3-sigma
upper limits (calibrated to R2 and B2 mag. of USNO-B1)
in the two bands:
t - t0 Exposure (s) Filter mag.
~17.4 h 780 R > 22.5
~17.5 h 780 B > 21.9
We are grateful to the TUBITAK National Observatory staff for promptly
scheduling the observations and their
technical support.
GCN Circular 12735
Subject
GRB 111225A: Swift/UVOT Observations
Date
2011-12-27T16:51:36Z (14 years ago)
From
Mike Siegel at PSU/Swift MOC <siegel@swift.psu.edu>
M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 111225A
95 s after the BAT trigger (Siegel et al., GCN Circ. 12720).
A source consistent with the XRT position is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 00:52:37.22 = 13.15510 (deg.)
Dec (J2000) = +51:34:19.5 = 51.57208 (deg.)
with an estimated uncertainty of 0.67 arc sec. (radius, 90% confidence).
The afterglow has not been detected since the first orbit. Preliminary detections and
3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u (fc) 95 345 246 19.46 +/- 0.17
v 610 18443 2140 >21.1
u 4385 16744 1475 >20.66
uvw1 659 12668 1212 >20.4
uvm2 634 11879 1337 >20.5
uvw2 354 17652 1780 21.36 +/- 0.31
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.26 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 12733
Subject
GRB 111225A: Keck/LRIS Afterglow Photometry
Date
2011-12-27T06:20:27Z (14 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko, J. S. Bloom, J. M. Silverman, A. N. Morgan (UC Berkeley), D.
A. Perley (Caltech), A. Cucchiara, J. X. Prochaska (UCSC / UCO Lick), A.
V. Filippenko (UC Berkeley), and P. E. Nugent (LBNL / UC Berkeley) report
on behalf of a larger collaboration:
We have imaged the field of GRB111225A (Siegel et al., GCN 12720) with the
Low-Resolution Imaging Spectrometer (LRIS) mounted on the 10 m Keck I
telescope beginning at 4:56 UT on 2012 Dec 26 (~ 25.1 hours after the
Swift BAT trigger). We detect the optical afterglow in both the g' and
R-band filters, with an approximate magnitude at this time of R ~ 23.2
(estimated uncertainty of 0.3 mag, due largely to preliminary calibration
with respect to the USNO-B1 catalog). Compared with previously reported
detections (Xin et al, GCN 12725, Gorosabel et al., GCN 12728), this
suggests a steep fading of the afterglow emission at this late time
(power-index alpha ~ 2.5).
GCN Circular 12731
Subject
GRB 111225A: PAIRITEL NIR Upper Limits
Date
2011-12-26T06:06:41Z (14 years ago)
From
Adam Morgan at U.C. Berkeley <qmorgan@gmail.com>
A. N. Morgan (UC Berkeley) reports:
We observed the field of GRB 111225A (Siegel et al., GCN 12720) with
the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began
at 2011-12-26 01h13m05 UT, ~21.35 hr after the Swift Trigger. In
mosaics taken simultaneously in the J, H, and Ks filters, we do not
detect the optical afterglow (Siegel et al., GCN 12720; Klotz et al.,
GCN 12722; Updike et al., GCN 12723; Xin et al., GCN 12725; Gorosabel
et al., GCN 12728).
The preliminary photometry yields:
post burst
t_mid(h) exp.(s) filt U. Limit (3 sig)
22.45 4774 J > 18.4
22.45 4774 H > 17.6
22.45 4774 Ks > 16.9
All magnitudes are given in the Vega system, calibrated to 2MASS. No
correction for Galactic extinction has been made to the above reported
values.
GCN Circular 12730
Subject
GRB111225A: MITSuME Okayama optical upper limits
Date
2011-12-26T02:09:16Z (14 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME collaboration:
We observed the field of GRB 111225A (Siegel et al., GCNC 12720)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2011-12-25 09:00:08 UT (~5.2 hours
after the burst). We did not find any new point source within the
enhanced XRT error circle (Evans et al., GCNC 12724) and could not
detect the previously reported afterglow (Klotz et al., GCNC 12722;
Updike et al., GCNC 12723) in g' and Ic bands.
Three sigma upper limits of the OT are listed below. We used
GSC2.3 catalog for flux calibration.
T0+[day] MID-UT T-EXP[sec] g' Ic
------------------------------------------------------
0.25569 09:58:49 5700.0 >20.2 >19.6
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 12729
Subject
GRB 111225A: GRT Optical Observation
Date
2011-12-26T00:16:14Z (14 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori.sakamoto-1@nasa.gov>
T. Sakamoto (UMBC/GSFC), D. Donato (ORAU/GSFC), N. Gehrels (GSFC),
T. Okajima (GSFC), Y. Urata (NCU)
We observed the field of GRB 111225A detected by Swift
(trigger #510341; Siegel et al., GCN Circ. 12720) with the 14-inch
Goddard Robotic Telescope (GRT) located at the Goddard Geophysical
and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/).
A total 20 images of 60 sec (10 images), 180 sec (5 images) and
300 sec (5 images) exposures were taken in the R filter starting
from December 25 03:52:12 (UT) about 94 seconds after the trigger
(50 seconds after the BAT position notice) and stopped on December 25
04:43:53 (UT). We do not detect the optical afterglow both in the
individual images and the stacked image inside the enhanced XRT position
(Evans et al., GCN #12724). The estimated upper limit of the combined
image (total exposure of 3000 sec) is ~18.5 mag using the USNO-B1 catalog.
GCN Circular 12728
Subject
GRB 111225A: 1.23m CAHA optical observations
Date
2011-12-25T22:59:12Z (14 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Gorosabel (IAA-CSIC), P. Martorell (Obs. Guirguillano), P. Kubanek
(IAA-CSIC & U. Valencia), S. Mottola (DLR, Berlin), report on behalf
of a larger collaboration:
"We have observed the field of GRB 111225A (Siegel et al. GCNC 12720)
with the 1.23m CAHA telescope. The observations were carried out in
Dec 25.74725 - 25.83561 UT (14.1--16.2 hours post burst) in the R-band
with a total exposure time of 11x300+15x180s. We detect the optical
afterglow of the burst with an R-band magnitude of R=21.60+/-0.16,
with respect to the USNO B1.0 catalogue."
GCN Circular 12727
Subject
GRB 111225A: Swift-XRT refined Analysis
Date
2011-12-25T16:01:44Z (14 years ago)
From
Binbin Zhang at PSU <bbzhang@psu.edu>
B.-B. Zhang and M. H. Siegel (PSU) reports on behalf of the Swift-XRT
team:
We have analysed 10 ks of XRT data for GRB 111225A (Siegel et al. GCN
Circ. 12720), from 94 s to 23.3 ks after the BAT trigger. The data
comprise 556 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Evans et al. (GCN. Circ 12724).
The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=0.6 (+0.4, -0.3). At T+114 s the decay
steepens to an alpha of 1.83 (+0.10, -0.09). The light curve breaks
again at T+353 s to a decay with alpha=3.1 (+/-0.5), before a final
break at T+590 s s after which the decay index is 1.80 (+0.11, -0.12).
An early time flare (from T+214.6 to T+321.8 s) and a possible late
time flare (from ~T+20000s) are excluded from the fit.
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.43 (+/-0.07). The
best-fitting absorption column is 2.09 (+0.16, -0.15) x 10^21 cm^-2,
in excess of the Galactic value of 1.7 x 10^21 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.71 (+0.17, -0.15)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 4.5 x 10^-11 (5.7 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 0 (+7.7, -0) x 10^20 cm^-2
Galactic foreground: 1.7 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.71 (+0.17, -0.15)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00510341.
This circular is an official product of the Swift-XRT team.
GCN Circular 12726
Subject
GRB 111225A, Swift-BAT refined analysis
Date
2011-12-25T15:51:38Z (14 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori.sakamoto-1@nasa.gov>
W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. H. Siegel (PSU)
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 111225A (trigger #510341)
(Siegel, et al., GCN Circ. 12720). The BAT ground-calculated position is
RA, Dec = 13.158, 51.573 deg which is
RA(J2000) = 00h 52m 37.9s
Dec(J2000) = +51d 34' 21.8"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 93%.
The mask-weighted light curve shows a FRED like structure with the emission
starting at ~T-15 sec, peaking at ~T-5 sec and ending at ~T+150 sec.
T90 (15-350 keV) is 106.8 +- 26.7 sec (estimated error including systematics).
The time-averaged spectrum from T-14.28 to T+111.24 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.70 +- 0.15. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T-4.40 sec in the 15-150 keV band
is 0.7 +- 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/510341/BA/
GCN Circular 12724
Subject
GRB 111225A: Enhanced Swift-XRT position
Date
2011-12-25T08:38:19Z (14 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1857 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 111225A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 13.15557, +51.57157 which is equivalent
to:
RA (J2000): 00h 52m 37.34s
Dec (J2000): +51d 34' 17.6"
with an uncertainty of 2.2 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 12723
Subject
GRB 111225A: Super-LOTIS early detection
Date
2011-12-25T05:51:01Z (14 years ago)
From
Adria C. Updike at Clemson U <aupdike@clemson.edu>
Adria C. Updike (Dickinson College), Dieter H. Hartmann (Clemson
University), Peter A. Milne (Steward Observatory) and G. Grant Williams
(MMT Observatory) report:
We observed the field of GRB 111225A (Siegel et al., GCN 12720) with the
0.6m Super-LOTIS telescope located at Kitt Peak National Observatory under
good conditions and airmass of 1.1. Observations began 49 seconds after
the trigger. The OT (Siegel et al. GCN 12720, Klotz et al. GCN 12722) is
marginally detected in 300 seconds of stacked images (with a midtime of
480 seconds after the trigger) with an R-band magnitude of 19.9 +/- 0.2
(on comparison to the USNO B1.0 catalog). Observations are continuing.
This message may be cited.
GCN Circular 12722
Subject
GRB 111225A: TAROT Calern observatory optical detection
Date
2011-12-25T04:59:02Z (14 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz A. (IRAP-OMP), Gendre B. (ASDC/INAF-OAR),
Boer M. (OCA-CNRS), Atteia J.L. (IRAP-OMP) report:
We imaged the field of GRB 111225A detected by SWIFT
(trigger 510341) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.
Following the previous report (Klotz et al. GCNC 12721)
we co added only long exposure images obtained later
than 1100 seconds after the trigger and we detect
marginally the UVOT OT mentioned by Siegel et al.
(CGNC 12720):
t0+1100s to t0+1800s : R = 19.1 (+/- 0.6)
The OT detected by TAROT has a comparable magnitude
as NOMAD1 1415-0026136 locaded 20 arcsec from the
UVOT OT position.
This message may be cited.
GCN Circular 12721
Subject
GRB 111225A: TAROT Calern observatory optical observations
Date
2011-12-25T04:31:51Z (14 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR),
Boer M. (OHP-CNRS), Atteia J.L. (IRAP-CNRS-OMP) report:
We imaged the field of GRB 111225A detected by SWIFT
(trigger 510341) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.
The observations started 59.7s after the GRB trigger
(15.5s after the notice). The elevation of the field decreased from
10 degrees above horizon and weather conditions
were good.
The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT in the XRT error box (Siegel et al.
CGNC 12720) with a limiting magnitude of:
t0+59.7s to t0+119.7s : R > 15.9
The second image is 30.0s exposure in tracking mode:
t0+134.4s to t0+164.4s : R > 16.2
We co-added a series of exposures:
t0+134.4s to t0+326.7s : R > 18.0
No OT was detected in the next images until
t0+1700s at the level R > 17.6.
Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.
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GCN Circular 12720
Subject
GRB 111225A: Swift detection of a burst with an optical counterpart
Date
2011-12-25T04:12:26Z (14 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
M. H. Siegel (PSU), W. H. Baumgartner (GSFC/UMBC),
M. M. Chester (PSU), N. Gehrels (NASA/GSFC), D. Grupe (PSU),
F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),
D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC), C. A. Swenson (PSU),
T. N. Ukwatta (MSU) and B.-B. Zhang (PSU) report on behalf of the
Swift Team:
At 03:50:37 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 111225A (trigger=510341). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 13.102, +51.589 which is
RA(J2000) = 00h 52m 24s
Dec(J2000) = +51d 35' 19"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The immediately available lightcurve was
truncated for contact with the ground station. The BAT lightcurve showed
a rise at around T-10 seconds with flux continuing at least until
T+8 seconds, the limit of of the immediately available data.
The peak count rate was ~1300 counts/sec (15-350 keV), at ~-2 sec
after the trigger.
The XRT began observing the field at 03:52:05.9 UT, 88.1 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 13.1548, 51.5741 which is equivalent to:
RA(J2000) = +00h 52m 37.15s
Dec(J2000) = +51d 34' 26.8"
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This
location is 129 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy.
The initial flux in the 2.5 s image was 2.96e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 250 seconds with the U filter starting 95
seconds after the BAT trigger. There is a candidate afterglow in the rapidly
available 2.7'x2.7' sub-image at
RA(J2000) = 00:52:37.21 = 13.15503
DEC(J2000) = +51:34:19.5 = 51.57207
with a 90%-confidence error radius of about 0.75 arc sec. This position is 7.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.42 with a 1-sigma error of about 0.20. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.26.
Burst Advocate for this burst is M. H. Siegel (siegel AT astro.psu.edu).
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.)