GRB 111228A
GCN Circular 12737
Subject
GRB 111228A: Swift detection of a burst with an optical counterpart
Date
2011-12-28T16:00:13Z (13 years ago)
From
David Burrows at PSU/Swift <burrows@astro.psu.edu>
T. N. Ukwatta (MSU), W. H. Baumgartner (GSFC/UMBC),
D. N. Burrows (PSU), S. Campana (INAF-OAB), P. D'Avanzo (INAF-OAB),
B. Gendre (ASDC), C. Guidorzi (U Ferrara),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
H. A. Krimm (CRESST/GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU),
C. B. Markwardt (NASA/GSFC), A. Melandri (INAF-OAB),
J. P. Osborne (U Leicester), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU), E. Sonbas (NASA/GSFC/Adiyaman Univ.) and
E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:
At 15:44:43 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 111228A (trigger=510649). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 150.079, +18.293 which is
RA(J2000) = 10h 00m 19s
Dec(J2000) = +18d 17' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a strong triple-peaked
structure with a duration of about 100 sec. The peak count rate
was ~5000 counts/sec (15-350 keV), at ~93 sec after the trigger.
The XRT began observing the field at 15:47:08.6 UT, 145.1 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 150.06478, 18.29912 which
is equivalent to:
RA(J2000) = 10h 00m 15.55s
Dec(J2000) = +18d 17' 56.8"
with an uncertainty of 4.2 arcseconds (radius, 90% containment). This
location is 53 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. We
cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (2.95 x
10^20 cm^-2, Kalberla et al. 2005), with an excess column of 2.4
(+2.09/-1.76) x 10^21 cm^-2 (90% confidence).
The initial flux in the 0.1 s image was 8.82e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 155 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 10:00:16.01 = 150.06669
DEC(J2000) = +18:17:51.8 = 18.29773
with a 90%-confidence error radius of about 0.75 arc sec. This position is 8.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.19 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.03.
Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com).
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.)
GCN Circular 12738
Subject
GRB 111228A: Xinglong TNT confirms the optical afterglow
Date
2011-12-28T16:46:27Z (13 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L.P. Xin, J. Z. Li, J.Y. Wei, Y. L. Qiu, J. Wang, J.S. Deng,
C. Wu, X. H. Han on behalf of EAFON report:
We began to observe GRB 111228A (Ukwatta et al., GCN 12737)
with Xinglong TNT telescope at 15:46:18 (UT), about 96 sec after
the burst. A series of White, R-band images were obtained.
The optical counterpart (Ukwatta et al., GCN 12737)
was detected in all the images.
The brightness of OT is about 16.5 magnitude at the
mean time of 106 sec after the burst,
relatively to USNO B1.0 catalogure.
Follow-up observations are ongoing.
This message may be cited.
For more information about Xinglong GRBs Follow-up
observations, please visit the website:
http://www.xinglong-naoc.org:8080/grb/index.html"
GCN Circular 12741
Subject
GRB 111228A: Possible host galaxy in the SDSS arhive
Date
2011-12-28T20:40:10Z (13 years ago)
From
Tolga Guver at UA <tolga@physics.arizona.edu>
Guver, T. (Sabanci Univ.)
The field of the GRB 111228A (Ukwatta et al. GCN 12737) was observed
with the SDSS survey (Abazajian et al. 2009, ApJS, 182, 543).
Within 2.2 arcseconds of the XRT coordinates, SDSS detected a galaxy namely
SDSS J100015.45+181755.1. The exact coordinates of the galaxy are given as
RA : 150.06439037, DEC : +18.29865952 (J2000).
SDSS magnitudes of the galaxy are :
u = 21.99 +/- 0.20
g = 21.34 +/- 0.05
r ��= 20.90 +/- 0.05
i ��= 20.72 +/- 0.06
z = 20.72 +/- 0.21
SDSS also provides a photometric redshift for the galaxy as z =
0.192859 +/- 0.04821.
For further information SDSS page for the galaxy is :
http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237667734494445890
----------------------------------------------------------------
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GCN Circular 12742
Subject
GRB 111228A: TAROT Calern observatory. OT seems still bright
Date
2011-12-28T21:48:59Z (13 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 111228A detected by SWIFT
(trigger 510649) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.
The trigger occured during daytime over Calern.
The observations started 289 min after the GRB trigger
The elevation of the field increased from 7 degrees
above horizon and weather conditions were good.
We detect the candidate couterpart mentioned by Ukwatta et al.
(GCNC 12737) and confirmed by Xin et al. (GCNC 12738) using
a co-addition of 10 images of 3mins. Surprisingly, the OT
is bright R~18 (Tstart=289 min, Tend=336 min) corresponding
to an optical decay alpha~0.3 taken TNT and TAROT data.
We suspect a rebrightening occured during the first minutes
after the trigger.
Netherveless, the low elevation and the 3 arcsec/pix
sampling of TAROT does not allow to discriminate
the OT from the star NOMAD1 1082-0210617 (RA=150.0646861
DEC=+18.2997694 R=19.9). Now TAROT continues observations
in better airmass conditions but other observations are
encouraged.
This message may be cited.
GCN Circular 12743
Subject
GRB111228A: MITSuME Okayama Optical Observation
Date
2011-12-28T21:50:56Z (13 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 (Ukwatta et al., GCNC 12737)
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 2011-12-28 15:47:03 UT (~2.3 min after
the burst). We detected the previously reported afterglow
(Ukwatta, GCNC 12737; Xin et al., GCNC 12738) in all the three bands.
Photometric results and are listed below. We used SDSS catalog for
flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err
----------------------------------------------------------------------
0.00511 15:52:04 540.0 17.45 0.06 17.13 0.05 16.52 0.05
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 12744
Subject
GRB 111228A: Fermi GBM observation
Date
2011-12-28T23:03:23Z (13 years ago)
From
Michael S. Briggs at UAH and MSFC <michael.briggs@nasa.gov>
M. S. Briggs (UAH) and G. Younes (USRA)
report on behalf of the Fermi GBM Team:
"At 15:45:30.80 UT on 28 Dec 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 111228A (trigger 346779932 / 111228657),
which was also detected by the Swift BAT/XRT/UVOT (Ukwatta et al.
2011, GCN 12737). The GBM on-ground location is consistent with the
Swift position. The angle from the Fermi LAT boresight is 70 degrees.
The GBM light curve shows multiple peaks in three groups
with a duration (T90) of about 100 s (50-300 keV) starting
50 seconds before the GBM trigger time. The time-averaged spectrum
from T0+0 s to T0+57 s is well fit by a power law function with an
exponential high-energy cutoff. The power law index is -1.9 +/- 0.1
and the cutoff energy, parameterized as Epeak, is 34 +/- 4 keV
A Band function fits the spectrum equally well with
Epeak= 34 +/- 3 keV, alpha = -1.9 +/- 0.1 and beta = -2.7 +/- 0.3.
The event fluence (10-1000 keV) in this time interval is
1.8E-5 erg/cm^2. The 64 ms peak photon flux measured
starting from T0+7.7 s in the 10-1000 keV band
is 27 +/- 1 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 12745
Subject
GRB 111228A, optical observations
Date
2011-12-29T00:09:07Z (13 years ago)
From
Shashi Bhushan Pandey at ROTSE <shaship@umich.edu>
S. B. Pandey, Vijay Kumar Bhatt, Brajesh Kumar and Ram Kesh Yadav (ARIES,
NainiTal, India, on behalf of larger Indian GRB collaboration).
We have observed GRB 111228A field (Ukwatta et al., GCN 12737; Briggs and
Younes, GCN 12744) with the 1.04m telescope at ARIES NainiTal starting
~1.9 hours post-burst. Several sets of exposures varying 100s to 300 s each
were taken in Bessel filters. The afterglow candidate (Xin et al., GCN
12738)
is visible in individual frames.
Preliminary photometry of the R_c band data in comparison to nearby USNO
stars,
indicates that the afterglow candidate has decayed by ~ 0.7 mag in ~ 3.5
hours
of observations. This corresponds to a temporal decay index of ~ 0.3,
similar
to what has been noticed by Klotz et al. (GCN 12742). Further observations
are
continued.
This message may be cited.
GCN Circular 12746
Subject
GRB 111228A: TAROT Calern observatory. OT decay stopped
Date
2011-12-29T00:14:59Z (13 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 continue to obtain images of the field of GRB 111228A detected
by SWIFT (trigger 510649) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France (cf. GCNC 12742).
We confirm the OT observed by TAROT is not the galaxy
mentioned by Guver (GCNC 12741) neither the object
referenced as NOMAD1 1082-0210617 (Klotz GCNC 12742).
The OT observed by TAROT is the afterglow of GRB 111228A
and lies 9 arcsec eastern from these objects.
As we previously announced (GCNC 12742), we confirm that
the OT of GRB 111228A is brighter than a simple extrapolation
of the very early observations using a standard decay.
Current TAROT observations show that the decay is stopped.
Unfiltered TAROT images were co-added
to obtain a temporal series that shows clearly that
the brightness remains almost constant since the beginning
of the TAROT observations.
Photometry is relative to the star NOMAD1 1083-0203467
(RA=150.0946028 DEC=+18.3231806 J2000) R=17.28 (V-R)=+0.69.
Tstart Tend Rmag OT
(min) (min)
289 318 18.6 +/- 0.4
321 352 18.9 +/- 0.4
358 389 18.5 +/- 0.3
392 421 18.7 +/- 0.3
429 459 18.7 +/- 0.3
462 492 18.9 +/- 0.3
This message may be cited.
GCN Circular 12747
Subject
GRB 111228A: Enhanced Swift-XRT position
Date
2011-12-29T00:26:33Z (13 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1689 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 111228A, 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 = 150.06699, +18.29781 which is equivalent
to:
RA (J2000): 10h 00m 16.08s
Dec (J2000): +18d 17' 52.1"
with an uncertainty of 1.4 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 12748
Subject
GRB 111228A: optical observations
Date
2011-12-29T01:07:55Z (13 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
V. Nascimbeni (Univ. Padova), E. Palazzi (INAF-IASFBo), D. Fugazza, A.
Melandri, S. Covino (INAF-OABr), L. Borsato, A. Cunial, V. Granata
(Univ. Padova), report on behalf of a larger collaboration:
We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with
the 1.82m Asiago Telescope equipped with the AFOSC optical camera. A 900
s R-band image was acquired with mean time Dec 28.939 UT (6.79 hr after
the burst trigger).
We clearly detect the afterglow (Ukwatta et al., GCN 12737; Xin et al.,
GCN 12738; Klotz et al., GCN 12472) at a magnitude R = 18.6 +/- 0.02
assuming R = 17.28 for the star USNO-B1 1083-0199833 (RA = 10:00:22.72,
Dec = +18:19:23.85 - same as used by Klotz et al., GCN 12746).
We also clearly detect the SDSS object reported by Guver (GCN 12741),
and confirm that it is not related to the GRB (Klotz et al., GCN 12746).
Further observations are underway.
GCN Circular 12749
Subject
GRB 111228A, Swift-BAT refined analysis
Date
2011-12-29T01:16:35Z (13 years ago)
From
Hans Krimm at NASA-GSFC <hans.a.krimm@nasa.gov>
J. R. Cummings (GSFC/UMBC),S. D. Barthelmy (GSFC),
W. H. Baumgartner (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), M. Stamatikos (OSU), J. Tueller (GSFC),
T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+746 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 111228A (trigger #510649)
(Ukwatta, et al., GCN Circ. 12737). The BAT ground-calculated position is
RA, Dec = 150.063, 18.284 deg which is
RA(J2000) = 10h 00m 15.0s
Dec(J2000) = +18d 17' 02.2"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 39%.
The mask-weighted light curve shows multiple peaks in several clusters. The first
set of peaks is at a low level from T-12 s to T+12 s. There is another low level
set from T+32 to T+42 s, followed by a much brighter set of three overlapping peaks
from T+45 to T+60 s. The final cluster is broad and relatively soft from T+85
to T+110 s. T90 (15-350 keV) is 101.20 +- 5.42 sec (estimated error including
systematics).
The time-averaged spectrum from T-12.82 to T+115.43 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.27 +- 0.06. The fluence in the 15-150 keV band is 8.5 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+54.56 sec in the 15-150 keV band
is 12.4 +- 0.5 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/510649/BA/
GCN Circular 12750
Subject
GRB 111228A: NOT optical observation
Date
2011-12-29T03:04:32Z (13 years ago)
From
Dong Xu at Weizmann Inst <dong.dark@gmail.com>
D. Xu (WIS/NAOC), J. McCormac (Queen's Univ. Belfast), and P.
Jakobsson (Univ. Iceland) report on behalf of a larger collaboration:
We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with
the 2.5m Nordic Optical Telescope (NOT) equipped with the AFOSC
optical camera. A 600s R-band image was taken with mean time 01:32 UT
on 2011-12-29 (9.8 hr after the burst trigger).
We clearly detected the afterglow (Ukwatta et al., GCN 12737; Xin et
al., GCN 12738; Klotz et al., GCN 12742) at a magnitude R = 19.01 +/-
0.05, calibrated with the USNO-B1 1083-0199833 star (R2 = 17.28 mag;
also used by Klotz et al., GCN 12746 and Nascimbeni et al., GCN
12748).
Further observations are ongoing.
GCN Circular 12751
Subject
GRB 111228A: Skynet/Dolomiti Optical Observations
Date
2011-12-29T03:51:36Z (13 years ago)
From
Melissa Nysewander at UNC-Chapel Hill <mnysewan@unc.edu>
M. Nysewander, J. Haislip, K. Ivarsen, A. LaCluyze, M. Maturi, D. Reichart, J. Moore, T. Cromartie, R. Egger, A. Foster, N. Frank, A. Oza, E. Speckhard, A.Trotter, and J. A. Crain report:
Skynet observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with the 16" Dolomites Astronomical Observatory telescope (DAO) in Italy beginning 6.4 hrs after the burst, and lasting for one hour.
We detect the afterglow in g' (11 x 180s) and r' (7 x 180s) exposures. Using ~20 SDSS field stars, we measure the OT to be g' = 19.4 +- 0.1 at 6.73 hours and r' = 19.3 +- 0.2 at 7.30 hours in stacked images. The OT faded by r' ~ 0.1 mag from 7.15 to 7.41 hours.
GCN Circular 12752
Subject
GRB 111228A: Swift/UVOT Detection
Date
2011-12-29T04:40:16Z (13 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (MSSL-UCL) and Ukwatta (MSU) report on
behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of
GRB 111228A 155 s after the BAT trigger (Ukwatta et al.,
GCN Circ. 12737). The UVOT position is consistent with
the enhanced XRT position (Goad et al., GCN Circ. 12747)
within the measurement accuracy.
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
white 155 305 147 17.30 +/- 0.03
v 389 759 58 17.73 +/- 0.16
b 488 508 19 17.71 +/- 0.15
u 463 483 19 16.70 +/- 0.12
w1 439 459 19 16.59 +/- 0.17
m2 764 784 19 16.84 +/- 0.24
The preliminary lightcurves show achromatic behavior during the
first 1200s and appears to maintain brightness levels until around
7000s after the trigger, when the decay in brightness sets in.
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 12753
Subject
GRB 111228A: IAC80 BVI-band observations
Date
2011-12-29T05:10:43Z (13 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Gorosabel (IAA-CSIC), R. Gimeno (IAC), A. Nicuesa Guelbenzu (TLS Tautenburg), report on behalf of a larger collaboration:
"We observed the field of GRB 111228A (Ukwatta et al., GCNC 12737) with the 82cm IAC80 telescope at the Observatorio del Teide, Tenerife, Spain. The observations were carried in the BVI-bands on Dec 29.08662 - 29.19141 UT (10.3-12.8 hours post burst). The optical afterglow of the burst (Ukwatta et al., GCNC 12737; Xin et al., GCNC 12738; Klotz et al., GCNC 12742; Pandey et al. GCN 12745; Nascimbeni et al. GCNC 12748; Xu et al., GCNC 12750; Nysewander et al. GCN 12751; Kuin et al. GCN 12752) is well detected in the three bands with an approximate magnitude of I~18.5 with respect to the USNO B1.0 catalogue."
GCN Circular 12754
Subject
GRB 111228A: GRAS017 optical observations
Date
2011-12-29T05:24:38Z (13 years ago)
From
Veli-Pekka Hentunen at Taurus Hill Obs,A95 <veli-pekka.hentunen@kassiopeia.net>
Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill
Observatory, Varkaus, Finland) report:
GRAS 017 (Global-Rent-a-Scope, Nerpio, Spain) CDK17 17" (0.43 m)
f/6.8 and FLI ProLine CCD camera were used to detect GRB 111228A
optical afterglow 9.0 hours after the burst trigger. The observations were
started at 2011-12-29 00:35:06 (UT) and stopped at 2011-12-29 00:58:26
(UT). Nine photometric R observations with 120s exposure times were
made. The afterglow was detected at following position RA 10 00 16.07
and DEC +18 17 52.1.
The following magnitude was obtained from the observations using
USNO-B1 1083-0199853 (R2 = 17.28) as the comparison:
Tmid(s)+T0 Filter Exp (sec) Mag Mag err Limit
32522 R 9x120 18.7 0.2 19.8
A png image of our observations is available at the following URL link:
http://cutenews.kassiopeia.net/data/upimages/GRB111228A_web.png
GCN Circular 12755
Subject
GRB111228A: Errata of MITSuME Okayama about GRB name in GCNC 12743
Date
2011-12-29T05:35:53Z (13 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:
The GRB name reported in GCNC 12743 is incorrect.
We revise as follows:
We observed the field of GRB 111228A (Ukwatta et al., GCNC 12737)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
GCN Circular 12756
Subject
GRB 111228A: MASTER OT observations
Date
2011-12-29T07:29:24Z (13 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Sinykov, V.Yurkov, Yu.Sergienko, D.Varda,
Blagoveschensk Educational State University, Blagoveschensk
E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski,
N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, A.Kuznetsov,
D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov,
A.Sankovich, S. Shurpakov
Sternberg Astronomical Institute, Moscow State University
K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Gres,
O.Chuvalaev,E.Konstantinov,
Irkutsk State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinski, I.Zalozhnich, A. Popov
Ural State University, Kourovka
MASTER II robotic double telescope (MASTER-Net:
http://observ.pereplet.ru) located in Blagoveschensk was pointed
to the GRB111228.66 191 sec after notice time and 244 sec after
GRB time at 2011-12-28 15:48:47.127 UT. The some delay was due to weather conditions.
On our first (20s exposure, two polarizations, unfiltered) set we found
optical transient at Swift OT position (Ukwatta et al., GCN Circ R12737).
The OT magnitude is about 16.5 mag in both polarizations.
The reduction is continuated.
The message may be cited.
GCN Circular 12757
Subject
GRB 111228A: GROND observations
Date
2011-12-29T07:55:33Z (13 years ago)
From
Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>
A. Nicuesa Guelbenzu, S. Klose (both TLS Tautenburg), and J. Greiner (MPE
Garching) report on behalf of the GROND team:
We observed the field of GRB 111228A (Ukwatta et al., GCN 12737)
simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120,
405) mounted at the 2.2-m MPG/ESO telescope on La Silla.
Observations started as soon the object was visible over La Silla, at
04:46 UT on December 29, about 13 hr after the burst. We detect the
afterglow (Ukwatta et al., GCN 12737; Xin et al., GCN 12738) in all bands.
At a mean time of December 29, 05:35 UT, in an 8min exposure, we measure
the following preliminary magnitudes (AB system):
g' = 20.17 +/- 0.01,
r' = 19.84 +/- 0.01,
i' = 19.67 +/- 0.02,
z' = 19.50 +/- 0.03,
J = 19.29 +/- 0.07,
H = 18.93 +/- 0.08.
The SED is best fit with a spectral slope of 0.90 +/- 0.05, with no
evidence for additional extinction.
Optical data are calibrated against SDSS and NIR data against 2MASS field
stars. Observations are continuing.
GCN Circular 12758
Subject
GRB 111228A: TAROT La Silla observatory observations
Date
2011-12-29T08:10:05Z (13 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 continue to obtain images of the field of GRB 111228A detected
by SWIFT (trigger 510649) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory, La Silla observatory,
Chile (early observations were done using TAROT Calern, reported
in GCNC 12742 and GCNC 12746).
Photometry is relative to the star NOMAD1 1083-0203467
(RA=150.0946028 DEC=+18.3231806 J2000) R=17.28 (V-R)=+0.69.
Tstart Tend Rmag OT
(min) (min)
788 837 19.0 +/- 0.4
840 890 19.2 +/- 0.3
Taking account for the magnitudes obtained earlier from TAROT Calern
we deduce that the plateau phase may be now finished and an optical
decay of ~0.5 could now occur.
This message may be cited.
GCN Circular 12759
Subject
GRB 111228A: MMT Redshift
Date
2011-12-29T08:16:27Z (13 years ago)
From
Edo Berger at Harvard <eberger@cfa.harvard.edu>
J. Dittman, T. Laskar, and E. Berger (Harvard) report:
"Starting on 2011 December 29.312 UT (15.7 hours after the burst) we
used the Blue Channel spectrograph mounted on the MMT 6.5-m telescope
to observe GRB111228A (GCN #12737). Our spectra cover the range
3400-8500A and reveal absorption lines of MgII and FeII at a common
redshift of z=0.714, which we consider to be the redshift of
GRB111228A. Additional observations are in progress."
GCN Circular 12760
Subject
GRB 111228A: PAIRITEL NIR Detection
Date
2011-12-29T08:18:18Z (13 years ago)
From
Adam Morgan at U.C. Berkeley <qmorgan@gmail.com>
GRB 111228A: PAIRITEL NIR Detection
A. N. Morgan (UC Berkeley) reports:
We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with
the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began
at 2011-12-29 06:55:25 UT, ~15.2 hours after the Swift Trigger. In
mosaics (effective exposure time of 0.46 hours) taken simultaneously
in the J, H, and Ks filters, we marginally detect a source at the
optical afterglow location (Ukwatta et al., GCN 12737; Xin et al., GCN
12738; Klotz et al., GCN 12742; Pandey et al., GCN 12745; Nascimbeni
et al., GCN 12748; Xu et al. GCN 12750; Nysewander et al., GCN 12751;
Kuin & Ukwatta, GCN 12752; Gorosabel et al., GCN 12753; Hentunen et
al., GCN 12754; Sinykov et al., GCN 12756; Guelbenzu et al., GCN
12757).
The preliminary photometry yields:
post burst
t_mid (hr) exp.(hr) filt mag m_err
15.56 0.46 J 18.3 0.2
15.56 0.46 H 17.8 0.3
15.56 0.46 Ks 16.2 0.3
All magnitudes are given in the Vega system, calibrated to 2MASS. No
correction for Galactic extinction has been made to the above reported
values. Further observations are ongoing.
GCN Circular 12761
Subject
GRB 111228A: Gemini South Redshift
Date
2011-12-29T08:25:14Z (13 years ago)
From
Antonino Cucchiara at LBNL <acucchiara@lbl.gov>
A. Cucchiara (UCSC/UCO Lick), A. J. Levan (U. Warwick),
and S. B. Cenko (UC Berkeley) report:
We obtained spectroscopy of the optical afterglow of
GRB 111228A (Ukwatta et al., GCN 12737) using GMOS-South
on the Gemini-South 8-m telescope.
Observations began on December 29.28 UT (15 hrs after the
BAT trigger).
Inspection of the first two exposures (range 4160-8140 Angstroms)
reveals MgII2796,2803, MgII2853 and CaH&K absorption features
at a common redshift of 0.716.
We therefore suggest this to be the redshift of GRB 111228A.
We thank the Gemini staff for performing this observation,
in particular Pascale Hibon.
GCN Circular 12763
Subject
GRB111228A: TNG spectroscopy analysis
Date
2011-12-29T12:36:46Z (13 years ago)
From
Dino Fugazza at INAF-OAB <dino.fugazza@brera.inaf.it>
E. Palazzi (INAF-IASFBo), D. Fugazza (INAF-OAB), S. Piranomonte
(INAF-OAR) on behalf of a larger collaboration report:
The afterglow of GRB 111228A (Ukwatta et al. GCN 12737) was observed
with the DOLORES instrument mounted at the Telescopio Nazionale Galileo
on La Palma, Canary Islands. Starting on December 29.1200 (~11 hour
after the burst), a series of three spectra of 1800s each were secured
with LR-B grism (range 3500-8000 Angstroms).
Preliminary reduction of the spectra reveals absorption features that we
identify with the following absorption lines:
Lines ID Lambda_observed
(Angstroms)
FeII_2344.21 4019.83
FeII_2374.46 4073.40
FeII_2382.76 4088.32
FeII_2585.65 4436.05
FeII_2600.17 4460.64
MgII_2795.50 4795.65
MgII_2802.70 4808.58
MgI_2852.96 4891.53
CaII_3933.68 6756.61
CaII_3968.49 6807.44
The derived redshift is z=0.7156 � 0.0005 which confirms the results
obatined by Dittman et al. (GCN 12759) and Cucchiara et al (GCN 12761).
In addition to the GRB afterglow we observed the SDSS galaxy reported by
Guver (GCN 12741). We detect many emission lines (OII_3726+3728, Hbeta,
OIII_4958, OIII_5006, Halpha) at a common redshift of 0.218 � 0.001
which is in agreement with the reported photometric redshift. This
galaxy is therefore not related to the GRB.
We acknowledge the excellent support from the TNG staff, in particular
Walter Boschin and Gianni Tessicini
[GCN OPS NOTE(22jan12): Per author's request, the affilation was changed
from "U.Milano-Bicocca,INAF/Brera" to "INAF-OAB".]
GCN Circular 12764
Subject
GRB 111228A: NOT redshift
Date
2011-12-29T12:43:17Z (13 years ago)
From
Dong Xu at Weizmann Inst <dong.dark@gmail.com>
D. Xu (WIS/NAOC), J.P.U. Fynbo (DARK), J. McCormac (Queen's Univ.
Belfast), and P. Jakobsson (Univ. Iceland) report on behalf of a
larger collaboration:
We secured spectroscopy of the afterglow of GRB 111228A (Ukwatta et
al., GCN 12737) with the 2.5m Nordic Optical Telescope (NOT) equipped
with the ALFOSC optical camera. Observations started immediately after
the 600s R-band photometry in Xu et al. (GCN 12750).
The NOT spectrum covers 2750-9000A and shows clear absorption lines of
MgII2803 and CaH&K, at a common redshift of z=0.713.
Further observations are planned.
GCN Circular 12766
Subject
GRB 111228A: Swift-XRT refined Analysis
Date
2011-12-29T13:01:33Z (13 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo (INAF-OAB) and T. N. Ukwatta (MSU) report on behalf of the
Swift-XRT team:
We have analysed 6.4 ks of XRT data for GRB 111228A (Ukwatta et al.
GCN Circ. 12737), from 135 s to 29.3 ks after the BAT trigger. The
data comprise 331 s in Windowed Timing (WT) mode (the first 9 s were
taken while Swift was slewing) with the remainder in Photon Counting
(PC) mode. The enhanced XRT position for this burst was given by Goad
et al. (GCN. Circ 12747).
The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=5.41 (+0.09, -0.07). At T+418 s the decay
flattens to an alpha of 0.26 (+0.05, -0.06) before breaking again at
T+6950 s to a final decay with index alpha=1.27 (+0.19, -0.15).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 4.16 (+0.12, -0.11). The
best-fitting absorption column is 2.92 (+0.18, -0.17) x 10^21 cm^-2,
in excess of the Galactic value of 3.0 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.19 (+0.11, -0.10)
and a best-fitting absorption column of 1.52 (+0.27, -0.26) x 10^21
cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.4 x 10^-11 (5.2 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.52 (+0.27, -0.26) x 10^21 cm^-2
Galactic foreground: 3.0 x 10^20 cm^-2
Excess significance: 7.9 sigma
Photon index: 2.19 (+0.11, -0.10)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00510649.
This circular is an official product of the Swift-XRT team.
GCN Circular 12767
Subject
GRB 111228A: GMG optical observation
Date
2011-12-29T15:16:14Z (13 years ago)
From
Xiao-hong Zhao at Yunnan Observatory <zhaoxiaohong78@gmail.com>
X.-H. Zhao (YNAO), D. Xu (WIS/NAOC), J.-R. Mao (KASI/YNAO), J.-M. Bai
(YNAO) report:
We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) at the
2.4m Gao-Mei-Gu (GMG) telescope equipped with YFOSC. Observations
started at 16:31:38 UT on 2011-12-28 (i.e., 47 mins after the burst) and
4x600s R-band images were obtained in a seeing of
~3.36". We found the afterglow was decaying. The results are as follows:
mid time (UT) magnitude (err)
2011-12-28 16:36:38 17.11 (0.01)
2011-12-28 17:19:14 17.42 (0.01)
2011-12-28 17:44:57 17.56 (0.01)
2011-12-28 17:56:15 17.62 (0.01).
The magnitudes were calibrated with the USNO-B1 #1083-0199833 star (R2 = 17.28 mag; also
used by Klotz et al., GCN 12746; Nascimbeni et al., GCN 12748; Xu et
al., GCN 12750; Hentunen et al., GCN 12754).
Further observations are planned.
We thank the GMG staff, especially Y.-X. Xin, Fen He, and Gui-Hua He for
performing these observations.
[GCN OPS NOTE(29dec11): Per author's request, the affiliation of X-H.Z.
was changed to Yunnan Observatory.]
GCN Circular 12768
Subject
GRB111228A: MITSuME Akeno photometry of the optical afterglow
Date
2011-12-29T15:34:59Z (13 years ago)
From
Yoichi Yatsu at Tokyo Tech. <yatsu@hp.phys.titech.ac.jp>
R. Usui, Y. Aoki, S. Song, M. Hayashi, K. Kawakami, K. Tokoyoda,
Y. Saito, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of
the MITSuME collaboration:
We observed the field of GRB 111228A (Ukwatta et al., GCNC 12737)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2011-12-28 15:45:47 UT (~ 64 sec after
the burst). We detected the previously reported afterglow
(Ukwatta, GCNC 12737; Xin et al., GCNC 12738) in all the three bands.
Photometric results and are listed below. We used GSC2.3 catalog for
flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err
----------------------------------------------------------------------
0.00074 15:46:02 30.0 17.3 0.2 16.12 0.09 15.5 0.1
----------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 12769
Subject
GRB 111228A: T100 observations
Date
2011-12-29T16:36:46Z (13 years ago)
From
Tolga Guver at UA <tolga@physics.arizona.edu>
T. Guver (Sabanci Univ.), E. Sonbas (Adiyaman Univ.), S. Kaynar
(Akdeniz Univ.), E. Gogus (Sabanci Univ.), Z. Eker (TUG) report on
behalf of a larger collaboration
We observed the field of Swift GRB 111228A (Ukwatta et al., GCN 12737)
with the 1.0 meter T100 telescope (TUBITAK National Observatory,
Antalya - Turkey), starting December, 28, 22:48 UT (~ 7 hours after
the trigger). Observations were carried out in the B, R, and V filters
under good weather conditions. The afterglow is clearly detected in
all images.
Using the USNO-B1 star USNO-B1 1083-0199833 (RA = 10:00:22.72, Dec =
+18:19:23.85 - same as used by Klotz et al., GCN 12746 and Nascimbeni
et al., GCN 12748) in the field we estimated the following magnitudes
for the OT:
t - t0 (h) Exp. (s) Filter mag. err
6.859 300 B 19.12 +/- 0.04
6.958 300 B 19.56 +/- 0.07
8.219 300 B 19.58 +/- 0.04
8.317 300 B 19.39 +/- 0.05
7.057 300 R 18.45 +/- 0.02
7.155 300 R 18.50 +/- 0.02
8.416 300 R 18.58 +/- 0.02
8.514 300 R 18.61 +/- 0.03
We are grateful to the TUBITAK National Observatory staff for promptly
scheduling the observations and their technical support.
----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.
GCN Circular 12770
Subject
GRB 111228A: X-shooter spectroscopy
Date
2011-12-29T19:19:59Z (13 years ago)
From
Steve Schulse at U. of Iceland <steve@raunvis.hi.is>
S. Schulze (U Iceland), S. Covino (INAF-OABr), H. Flores (GEPI/Obs. de
Paris), J. P. U. Fynbo (DARK/NBI), B. Milvang-Jensen (DARK/NBI), J.
Sollerman (U Stockholm), D. Xu (WIS) report on behalf of the X-shooter
GRB collaboration:
We observed the afterglow of GRB 111228A (Ukwatta et al. GCN 12737)
with the ESO VLT equipped with the X-shooter spectrograph on 29
December 2011, beginning 07:40 UT (15.93 hr after the GRB). The
afterglow had an R-band brightness of 20.08 mag in a series of five
acquisition images with an exposure time of 30 s each (mid-exposure
time = 15.98 hours). The magnitude is not corrected for Galactic
extinction.
We acquired four spectra with an exposure time of 600 seconds each,
beginning at 07:47 UT. We detect several absorption lines
wave_obs wave_rest Ion redshift
(AA, vac) (AA, vac)
3880.28 2260.78 FeII 0.71634
4023.15 2344.21 FeII 0.71620
4075.26 2374.46 FeII 0.71629
4089.47 2382.77 FeII 0.71627
4422.70 2576.88 MnII 0.71630
4439.44 2586.65 FeII 0.71629
4453.10 2594.50 MnII 0.71636
4462.57 2600.17 FeII 0.71626
4799.05 2796.35 MgII 0.71618
4811.32 2803.53 MgII 0.71616
4896.33 2852.96 MgI 0.71623
6753.24 3934.78 CaK 0.71630
6813.09 3969.59 CaH 0.71632
at a common redshift of z = 0.71627 +/- 0.00002. In addition we detect
[OIII]5007 at z_em = 0.71635, similar to the absorption line redshift.
Our measurements confirm the results by of Cucchiara et al (GCN 12761)
and Palazzi et al (GCN 12763) and are similar to Dittmann et al (GCN
12759) and Xu et al (GCN 12764).
The seeing conditions over the entire campaign were around 0.8 arcsec.
We acknowledge the support of the VLT staff, in particular Claudio
Melo and Christophe Martayan.
GCN Circular 12771
Subject
GRB 111228A: P60 Observations
Date
2011-12-29T20:00:39Z (13 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration:
We have imaged the field of GRB111228A (Ukwatta et al., GCN 12737) with
the automated Palomar 60 inch telescope. Observations were obtained in
the r' and i' filters beginning at 10:27 UT on 2011 December 29 (~ 18.9
hours after the Swift trigger).
We detect the optical afterglow with a magnitude of r' = 20.3 +/- 0.1 mag
(AB, calibrated with respect to several point sources from the Sloan
Digital Sky Survey in the field). Compared with previous reported
measurements of the afterglow brightness, this suggests a steeper decay
than observed at early times (e.g., Klotz et al., GCN 12742).
Further observations are planned.
GCN Circular 12773
Subject
GRB 111228A: Liverpool Telescope Observations
Date
2011-12-29T21:14:20Z (13 years ago)
From
Carole Mundell at ARI, JMU,Liverpool <cgm@astro.livjm.ac.uk>
A. Melandri (INAF-OAB), C. Guidorzi (U. Ferrara), C. G. Mundell (Liverpool JMU)
and N. R. Tanvir (U. Leicester), on behalf of a large collaboration report:
"We observed the optical afterglow of GRB 111228A (Ukwatta et al., GCN
12737) with the 2-m Liverpool Telescope, starting at 02:55 UT on 2011 December 29. We
took a sequence of images in Br'i' bands, with exposure time of 300s for each
individual frame.
We clearly detect the optical afterglow in all individual images. In
stacked frames we find the following magnitudes for the OT:
Mid time from Total Exp Filter Magnitude
trigger (hr) (s)
--------------------------------------------------
12.08 4x300 r' 19.68 +- 0.06
13.28 3x300 r' 19.89 +- 0.09
12.54 5x300 i' 19.57 +- 0.05
11.34 4x300 B 19.71 +- 0.08
12.96 4x300 B 19.79 +- 0.11
--------------------------------------------------
The magnitudes are calibrated against nearby SDSS-5 (r' and i' bands) and
USNO-B1.0 (B band) field stars and are not corrected for the Galactic
extinction.
This message may be cited."
GCN Circular 12778
Subject
GRB111228A: Further GMG observations
Date
2011-12-30T04:04:44Z (13 years ago)
From
Xiao-hong Zhao at Yunnan Obs <zhaoxiaohong78@gmail.com>
X.-H. Zhao (YNAO), L. P. Xin (NAOC), J.-R. Mao (KASI/YNAO), J.-M. Bai
(YNAO) report on behalf of a larger collaboration:
We made a further observation of GRB 111228A (Ukwatta et al., GCN 12737) with 2.4m Gao-Mei-Gu (GMG) telescope. Observations
started at 16:07:37 UT on 2011-12-29 (i.e., ~24.4 hrs after the burst) . We found the afterglow has faded significantly. The magnitudes are as follows:
mid time (UT) Exp. (s) Filter magnitude (err)
2011-12-29 16:12:37 600 R 20.24 (0.12)
2011-12-29 16:27:55 600 V 20.67 (0.18)
2011-12-29 16:38:54 600 B 21.13 (0.15)
2011-12-29 16:52:46 600 R 20.33 (0.12)
2011-12-29 17:03:24 600 V 20.73 (0.18)
2011-12-29 17:14:06 600 B 21.31 (0.16)
2011-12-29 17:28:50 600 R 20.54 (0.13)
2011-12-29 17:39:39 600 V 20.96(0.21)
2011-12-29 17:51:19 600 B 21.40 (0.17)
The magnitudes were calibrated with the USNO-B1 #1083-0199833 star (R2 = 17.28 mag and (V-R)=+0.69; also
used by Klotz et al., GCN 12746; Nascimbeni et al., GCN 12748; Xu et
al., GCN 12750; Hentunen et al., GCN 12754; Klotz et al. GCN 12758).
We thank the GMG staff, especially Y.-X. Xin, Fen He, and Gui-Hua He for
performing these observations.
GCN Circular 12779
Subject
GRB 111228A: Continued Skynet PROMPT/Dolomiti Optical Observations
Date
2011-12-30T04:32:27Z (13 years ago)
From
Aaron LaCluyze at U.North Carolina <lacluyze@email.unc.edu>
A. LaCluyze, M. Nysewander, J. Haislip, K. Ivarsen, M. Maturi, D.
Reichart, J. Moore, T. Cromartie, R. Egger, A. Foster, N. Frank, A. Oza,
E. Speckhard, A.Trotter, and J. A. Crain report:
Skynet continued observing the field of GRB 111228A (Ukwatta et al., GCN
12737) with the PROMPT telescope array at CTIO in Chile and the 16"
Dolomites Astronomical Observatory telescope (DAO) in Italy.
We detect the afterglow in g', r', i' and B, R, I bands, with a
chromatic variation suggested by late time data. A preliminary light
curve, calibrated to SDSS catalog sources can be found at the following
link:
http://skynet.unc.edu/grb/grb111228a.png
Further observations are ongoing to attempt to confirm or refute the
chromatic variation.
GCN Circular 12784
Subject
GRB 111228A: SMARTS optical/IR afterglow observations
Date
2011-12-30T17:34:16Z (13 years ago)
From
Bethany Cobb at GWU <bcobb@gwu.edu>
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained
optical/IR imaging of the error region of GRB 111228A (GCN 12737,
Ukwatta et al.) with a mid-exposure time of 15.9 hours
(2011-12-29 07:39 UT) and 39.5 hours (2011-12-30 07:13 UT) post-burst.
Total summed exposure times amounted to 36 minutes in I and 30 minutes
in J.
The optical afterglow of GRB 111228A (e.g. GCN 12737, Ukwatta et al.;
GCN 12738, Xin et al.) is detected and observed to decay between our
imaging. Preliminary comparison to Landolt standard stars in the optical
and 2MASS stars in the IR indicates the following magnitudes
for the afterglow:
time post-burst I mag J mag
15.9 hours 19.3 +/- 0.1 20.6 +/- 0.1
39.5 hours 18.4 +/- 0.1 > 19.1 (3-sigma limit)
This indicates that the decay rate of the burst between ~16 and 40 hours
post burst is alpha ~ 1.3 (where afterglow flux is proportional
to t^-alpha). In agreement with Cenko et al. (GCN 12771), this later-time
decay is much steeper than the earlier-time decay noted by Klotz et al.
(GCN 12742) and Pandey et al. (GCN 12745).
GCN Circular 12785
Subject
GRB 111228A: correction to GCN 12784
Date
2011-12-30T17:52:34Z (13 years ago)
From
Bethany Cobb at GWU <bcobb@gwu.edu>
The data in the table in GCN 12784 was incorrectly placed. The corrected
table is given below.
time post-burst I mag J mag
15.9 hours 19.3 +/- 0.1 18.4 +/- 0.1
39.5 hours 20.6 +/- 0.1 > 19.1 (3-sigma limit)
We apologize for any confusion. We thank Adam Miller for pointing out this
error.
GCN Circular 12787
Subject
GRB 111228A: Optical and NIR observations with Kanata telescope
Date
2011-12-31T01:04:46Z (13 years ago)
From
Michitoshi Yoshida at HASC,Hiroshima U <yoshidam@hiroshima-u.ac.jp>
R. Itoh, K. Takaki, M. Yamanaka, M. Sasada, K. Sakimoto, M. Yoshida,
K. S. Kawabata, Y. Hanabata, M. Ohno, Y. Fukazawa (HiroshimaUniv.),
A. Nakashima (Tokyo Univ.) report on behalf of the Kanata collaboration:
We performed optical and near infrared observations of GRB 111228A
(Ukwatta et al., GCN 12737; Xin et al., GCN 12738) with the 1.5 m Kanata
Telescope of Higashi-Hiroshima observatory, Japan. The observation
started at 15:47 UT on 2011 December 28. We took a sequence of images
in Rc and K bands, and detected the optical-infrared afterglow of the
GRB (Veli-Pekka Hentunen et al. GCN 12754; Kuroda et al. GCN 12743;
Nicuesa Guelbenzu et al. GCN 12757; Usui et al. GCN 12768).
Photometric results are listed below. We used USNO-B1 catalog for flux
calibration of Rc band, and 2-MASS catalog for Ks band.
Mid time from Total Exp Filter Magnitude
trigger (hr) (s)
-------------------------------------------------
0.34 180x5 Ks 14.94 $B!^(B 0.10
1.12 300x10 Rc 17.67 $B!^(B 0.04
3.75 300x9 Rc 18.53 $B!^(B 0.02
-------------------------------------------------
GCN Circular 12788
Subject
GRB 111228A: correction for GCN 12787
Date
2011-12-31T01:21:32Z (13 years ago)
From
Michitoshi Yoshida at HASC,Hiroshima U <yoshidam@hiroshima-u.ac.jp>
R. Itoh, K. Takaki, M. Yamanaka, M. Sasada, K. Sakimoto, M. Yoshida,
K. S. Kawabata, Y. Hanabata, M. Ohno, Y. Fukazawa (HiroshimaUniv.),
A. Nakashima (Tokyo Univ.) report on behalf of the Kanata collaboration:
Character corruption occurred in the table of the Kanata telescope
photometric results inthe GCN circular 12787. We resubmit the corrected
table. We are sorry for the inconvenience.
Mid time from Total Exp Filter Magnitude
trigger (hr) (s)
-------------------------------------------------
0.34 180x5 Ks 14.94 +- 0.10
1.12 300x10 Rc 17.67 +- 0.04
3.75 300x9 Rc 18.53 +- 0.02
-------------------------------------------------
GCN Circular 12789
Subject
GRB 111228A: MASTER-Net optical photometry
Date
2011-12-31T08:48:50Z (13 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
V.Krushinski, I.Zalozhnich, A. Popov
Ural State University, Kourovka
E. Sinykov, V.Yurkov, Yu.Sergienko, D.Varda,
Blagoveschensk Educational State University, Blagoveschensk
E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski,
N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, A.Kuznetsov,
D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov,
A.Sankovich, S. Shurpakov
Sternberg Astronomical Institute, Moscow State University
K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Gres,
O.Chuvalaev,E.Konstantinov,
Irkutsk State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory
MASTER II robotic double telescope (MASTER-Net: http://observ.pereplet.ru)
located in Blagoveschensk was pointed
to the GRB111228A (Ukwatta et al., GCN Circ R12737) 191 sec after notice
time and 244 sec after
GRB time at 2011-12-28 15:48:47.127 UT (Sinykov et al., GCN Circ 12756).
MASTER II robotic double telescope (MASTER-Net:
http://observ.pereplet.ru)
located near Kislovodsk was pointed
to the GRB111228A ~6.5 hours after
GRB time at 2011-12-28 22:24:47 UT.
The results of our photometry are:
Date UT Exp mag Err Filter
Start (s)
2011-12-28 15:48:47.1 20 16.9 0.2 P|
2011-12-28 15:48:47.1 20 16.5 0.2 P-
2011-12-28 15:49:34.7 30 17.1 0.2 P|
2011-12-28 15:49:34.7 30 16.7 0.2 P-
2011-12-28 15:50:37.3 40 16.8 0.2 P|
2011-12-28 15:50:37.3 40 17.3 0.2 P-
2011-12-28 15:51:43.1 50 17.6 0.2 P|
2011-12-28 15:51:43.1 50 17.5 0.2 P-
2011-12-28 15:52:59.7 70 16.8 0.2 P|
2011-12-28 15:52:59.7 70 17.1 0.2 P-
2011-12-28 15:54:41.3 90 17.3 0.2 P|
2011-12-28 15:54:41.3 90 17.3 0.2 P-
2011-12-28 15:56:38.4 110 17.0 0.2 P|
2011-12-28 15:56:38.4 110 17.6 0.2 P-
2011-12-28 16:01:44.8 180 17.3 0.2 P|
2011-12-28 16:01:44.8 180 17.6 0.2 P-
2011-12-28 22:24:47.9 180 19.0 0.3 V
2011-12-28 22:24:47.9 180 18.3 0.3 R
2011-12-28 22:28:14.1 180 18.9 0.3 V
2011-12-28 22:28:14.1 180 18.8 0.3 R
2011-12-28 22:31:42.7 180 19.3 0.3 V
2011-12-28 22:31:42.7 180 18.6 0.3 R
2011-12-29 00:13:44.5 180 18.8 0.3 R
2011-12-29 00:17:12.7 180 19.4 0.3 R
2011-12-29 00:20:45.7 180 18.9 0.3 R
2011-12-29 00:20:45.7 180 19.5 0.3 V
2011-12-29 01:45:51.9 180 19.4 0.3 R
2011-12-29 01:52:48.1 180 18.7 0.3 R
P|, P- - are the 2 polarisations in white
The message may be cited.
GCN Circular 12790
Subject
Konus-Wind observation of GRB 111228A
Date
2011-12-31T11:38:24Z (13 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 111228A (Swift-BAT trigger #510649:
Ukwatta et al., GCN 12737; Cummings et al., GCN 12749)
triggered Konus-Wind at T0=56736.171s UT (15:45:36.171).
The light curve shows two groups of pulses separated by ~45 s.
A total duration of the burst is ~50 s.
The emission is seen up to ~1500 keV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB111228_T56736/
As observed by Konus-Wind the burst
had a fluence of (7.5 � 1.3)x10-6 erg/cm2,
and a 256-ms peak flux, measured from T0+3.584 s,
of (2.0 � 0.3)x10-6 erg/cm2/s
(both in the 20 keV - 2000 MeV energy range).
The time-integrated spectrum of the burst (measured from T0 to T0+49.408 s)
is best fit in the 20 keV - 2000 keV range
by a simple power law function with the photon
index of (2.4 � 0.2), chi2 = 53.7/62 dof.
The spectrum at the maximum count rate (measured from T0 to T0+8.448 s)
is also best fit in the 20 keV - 2000 keV range
by a simple power law function with the photon
index of (2.25 � 0.15), chi2 = 77.1/62 dof.
Assuming the redshift z~0.715 (Dittman et al., GCN 12759;
Cucchiara et al., GCN 12761; Palazzi et al., GCN 12765;
Xu et al., GCN 12764) and a standard cosmology model
with H_0 = 71 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73,
the isotropic energy release E_iso is (1.0 � 0.2)x10^52 erg, and
the isotropic peak luminosity L_iso_max is (4.6 � 0.7)x10^51 erg/s.
All the quoted results are preliminary.
All the quoted errors are at the 90% confidence level.
GCN Circular 12791
Subject
GRB 111228A: LOAO Optical Observation
Date
2011-12-31T11:58:29Z (13 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
Yiseul Jeon, Myungshin Im, Minsung Jang (CEOU/Seoul National
Univ.), and Yuji Urata (NCU) on behalf of a larger collaboration
We observed GRB 111228A (Ukwatta et al., GCN 12737) in
B- and R-bands with a 1 m telescope at Mt. Lemmon, Arizona, US.
The observation started at 2011-12-30 08:03:16 UT,
or 1.7 days after the BAT aleart. We detected the afterglow
in the images taken with both filters.
Using the the photometry calibration based on an USNO B1 star
USNO-B1 1083-0199833 with B=18.85 and R=17.28 following Klotz et al.
(GCN 12746), we find the following.
Filter Mid-Time[UT] Mid-Time[Since BAT] Mag
B-band 2011-12-30 08:33:55 40.82 hours 21.75+-0.14
R-band 2011-12-30 10:41:29 42.95 hours 20.67+-0.09
Further observation is ongoing. We thank the LOAO operator,
J. Yoon for his help with the observation.
GCN Circular 12792
Subject
GRB 111228A, optical observations
Date
2011-12-31T12:19:21Z (13 years ago)
From
Shashi Bhushan Pandey at ROTSE <shaship@umich.edu>
S. B. Pandey, R. K. S. Yadav, Ram Sagar (ARIES, NainiTal, India) and
C. S. Stalin (IIA, Bangaluru); on behalf of larger Indian GRB
collaboration.
The newly installed 1.3m Devasthal Fast Optical Telescope (79.7 E, 29.4 N,
altitude ~ 2450 m) started looking towards the Swift trigger 510649
(Ukwatta
et al., GCN 12373) ~ 2.7 hours after the burst. The optical afterglow
candidate (Ukwatta et al., GCN 12373; Xin et al., GCN 12738) was clearly
detected in the individual frames with an exposure time of 120 sec each,
taken in R_c band.
The decaying afterglow (Klotz et al., GCN 12742; Pandey et al., GCN 12745;
Cenko et al., GCN 12771) was also detected during the observations taken on
consecutive night in the frames having exposure time of 300 sec each.
Preliminary photometry of the frames yields following.
Time (UT) Exp (s) Filter Magnitude
-------------------------------------------------------------
2011-12-28,18:30:46.0 120 s R_c 18.1+/-0.1
2011-12-29,23:56:38.0 300 s R_c 19.8+/-0.1
-------------------------------------------------------------
The magnitudes are calibrated against nearby USNO stars. Further
observations
are continued.
This massage may be cited.
GCN Circular 12798
Subject
GRB 111228A: optical observations in CrAO
Date
2012-01-02T14:52:27Z (13 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 111128A (Ukwatta et al. GCN 12737) with Shajn
telescope of CrAO observatory between (UT) 2011-12-28T23:08:08 and
2011-12-29T01:04:41 under a mean seeing of 1.5". We took several frames
with exposure of 60 s in BVRI. The photometry optical afterglow (Ukwatta et
al. GCN 12737; Xin et al. GCN 12738) is based on the USNO B1.0 star
1083-0199833 (10 00 22.70 +18 19 23.5) assuming B=18.85, R=17.28, I=17.02
.
T0+ Filter, Exposure, OT, uplim (3 sigma)
(mid, d) (s)
0.3476 B 27x60 19.270 +/- 0.007 23.6
0.3491 R 27x60 18.710 +/- 0.005 23.5
0.3499 I 27x60 18.608 +/- 0.006 23.2
GCN Circular 12809
Subject
GRB111228A :LOAO R-band Observations
Date
2012-01-06T02:50:13Z (13 years ago)
From
Yiseul Jeon at SNU/CEOU <ysjeon@astro.snu.ac.kr>
Minsung Jang, Myungshin Im, Yiseul Jeon (CEOU/Seoul National Univ.), and
Yuji Urata (NCU) on behalf of a larger collaboration
We continued our observation (Jeon et al. GCN 12791) of GRB 111228A
(Ukwatta et al., GCN 12737) in R-band with a 1 m telescope at Mt. Lemmon,
Arizona, US. Data were taken at 2011-12-31 UT and 2012-01-01 UT. For both
of them, we detected the afterglow in stacked R-band images.
We used a USNO B1 star near the afterglow, USNO-B1 1083-0199833 with
R=17.28 following Klotz et al. (GCN 12746) for our photometry calibration,
and current, rough estimates are given below.
Mid-time [UT] | Mid-time[Since BAT] | Exptime [sec] | R-magnitude
|
-------------------------------------------------------------------------------------------------------------
2011-12-31 08:40:25 | 64.92 hours | 300sec X 7 | 21.5 +/-
0.28 |
2012-01-01 11:19:52 | 91.58 hours | 300sec X 9 | 22.3 +/-
0.36 |
We thank the LOAO operator, J. Yoon for his help with these observations.
GCN Circular 12832
Subject
GRB 111228A: optical observations
Date
2012-01-14T12:00:43Z (13 years ago)
From
Alina Volnova at SAI MSU <alinusss@gmail.com>
A. Volnova (SAI MSU), L. Elenin (KIAM), �A. Pozanenko (IKI) report on
behalf of larger GRB �follow-up collaboration:
We observed the field of GRB 111228A (Ukwatta et al., GCN 12737) with
0.45-m telescope of ISON-NM observatory on Dec. 29 at 11:55 (UT,
middle of exposure) in R band with mean FWHM of about 4.9". We took
several unfiltered frames with exposure of 60 s. In a stacked image we
detect an optical counterpart (Ukwatta et al., GCN 12737; Xin et al.,
GCN 12738). The photometry is based on the USNO-B1.0 star 1415-0025726
(RA = 10:00:22.70 Dec = +18:19:23.4, J2000) assuming R2 = 17.28:
T0+, � � � �Filter, �Exposure, � OT
(mid, d) � � � � � � (s)
0.84102 � �R �1800 � � �19.27+/-0.12
GCN Circular 12908
Subject
GRB 111228A: Possible host detected by Swift/UVOT
Date
2012-02-02T21:57:17Z (13 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
Paul Kuin (MSSL/UCL) and Tilan Ukwatta (MSU) reports on behalf of
the Swift UVOT Team:
Until recently, Swift UVOT continued observations in multiple filters
of GRB 111228A (Ukwatta et al., GCN Circ. 12737).
Based on the observations taken up to January 31, 2012 in the white filter,
a possible host is detected.
The UVOT position in decimal degrees of the GRB during the early and peak
emission period is: RA=150.06684 DEC=+18.297834, J2000 (sexagesimal
10:00:16.04, +18:17:52.20), consistent with the enhanced XRT position
reported in GCN Circ. 12747 by Goad et al.. The position of the late time
emission/possible host is: RA=150.06643 DEC=+18.297903, J2000
(sexagesimal 10:00:15.94, +18:17:52.45). The position of the late-time
emission is offset by 0.9" which is significantly larger than the
position error for a single uvot image of 0.5" (Breeveld et al., 2010,
MNRAS 406, 1587), and the unknown smaller position error when
comparing between summed UVOT images. The offset suggests that
the late-time emission is due to a different source, possibly the host.
Other evidence comes from a late time flattening of the light curve.
The late time count-rate light curve decays with a power index of -1.3
in nearly all bands. Taking that as the decay rate, the light curves
in white and uvw2 deviate at times more than 800ks after the trigger.
Extrapolating the power law decay and subtracting from the late-time
white count rate, we estimate a host magnitude in white = 24.6 (+0.4/-0.6) mag,
which corresponds to a host flux in the broadband white filter of
(2.05+/-0.8)x10^-7 Jy (3471 A).
GCN Circular 12918
Subject
GRB 111228A, the review of the sky area in plate archives
Date
2012-02-08T09:52:41Z (13 years ago)
From
Valentyna Golovnya at Main Astro Obs,Kyiv <golov_v@ukr.ne>
V.V.Golovnya (Main Astro Obs, Kyiv)
report:
We have undertaken the review of the sky area in vicinity of
GRB 111228� (M.R. Goad et al. GCN Circ.12747) 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
19900323/192716 GUA040C003372 14.5 15.05 1050-06177767
19920228/213449 GUA040C001967A 20.0 15.60 1050-06179692
19921201/032302 GUA040C002052A 18.0 15.05 1050-06177767
19921218/022500 GUA040C002075A 21.0 15.05 1050-06177767
19930211/220606 GUA040C002118 22.0 15.60 1050-06179692
19930314/204336 GUA040C002155 20.0 15.60 1050-06179692
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 23 minutes area around
the location given in M.R. Goad et al. GCN Circ. 12747:
RA(J2000) = 10h 00m 16.08s, Dec(J2000) = +18d 17'52.1"
Star USNOA2 - Comparison star.
The preview images of 6 areas together with
the 23x23 min.of arc area from SkyMap can be found in
http://gua.db.ukr-vo.org/img/grb/111228A/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 13069
Subject
GRB 111228A: possible detection of the SN with the TNG
Date
2012-03-16T13:03:08Z (13 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, A. Melandri (INAF-OAB), E. Palazzi (INAF-IASF Bo), S. Campana
(INAF-OAB), M. Della Valle (INAF-OAC), E. Pian (INAF-OATs), R. Salvaterra
(INAF-IASF Mi), G. Tagliaferri (INAF-OAB) report on behalf of the CIBO
collaboration:
We observed the optical counterpart of GRB 111228A (Ukwatta et al., GCN
12737) with the Italian 3.6m TNG telescope on 2012 Feb 1.16 UT (34.5 days
post burst) and March 13.91 UT (76.2 days post burst). Observations were
carried out in the R and I bands. The counterpart is well detected in the
two epochs in both filters, with a magnitude R = 24.3 in the March
observation (calibrated using Landolt standard stars). The late value is
likely dominated by the host galaxy.
Differential photometry reveals that the source faded between the two
epochs by 0.4 +/- 0.2 and 0.9 +/- 0.1 mag in the R and I band,
respectively. The observed fading indicates that a transient component was
present during our February observation. This could be due to residual
afterglow emission, or to the presence of an emerging supernova (SN).
After subtracting the host galaxy flux, the color of the transient on
February 1 is very red, with
R-I ~ 2. This color is not typical of GRB afterglows, and is much redder
than measured at early times for this object (e.g., r'-i' = 0.17 AB at t
= 0.57 days: Nicuesa Guelbenzu et al., GCN 12757). Such a red spectrum, on
the contrary, is consistent with that of a type-Ic SN at z=0.72 (e.g.,
Dittman et al., GCN 12759), since the observed R band corresponds to the
rest-frame U, where severe line blanketing suppresses the SN flux. Also,
the I-band magnitude of the transient is comparable to that of SN 1998bw
close to the peak of luminosity, placed at z=0.72.
Although a more accurate analysis of the afterglow behaviour is necessary,
based on the above arguments, we believe to have detected the emission
from the SN associated with GRB 111228A.
We acknowledge the TNG staff for their support, in particular Luca Di
Fabrizio and Daniele Carosati.