GRB 091127
GCN Circular 10400
Subject
GRB 091127: Detection of a Supernova
Date
2010-02-11T03:45:12Z (16 years ago)
From
Bethany Cobb at UC Berkeley <bcobb@astro.berkeley.edu>
B. E. Cobb, J. S. Bloom, S. B. Cenko, D. A. Perley (UC Berkeley) report on
behalf of a larger collaboration:
We have obtained multiple epochs of imaging of the field of GRB 091127
(Troja et al., GCN 10191) using the Gemini Multi-Object Spectrograph
(GMOS) on the 8 m Gemini South telescope and the ANDICAM instrument
on the 1.3m telescope at CTIO. For the first ~10 days post-burst, the
optical afterglow of the GRB (e.g. Smith et al., GCN 10192, Immler et al.,
GCN 10193, Cobb, GCN 10244) dominates the burst's optical emissions.
After 10 days post-burst, however, we find evidence of an additional
component of light which rises and then fades, and we consider this to be
due to an underlying SN related to this GRB.
The rise and decay characteristics of this GRB-SN are globally similar to
those of the prototypical GRB-SN, SN1998bw. The SN reaches peak
brightness at approximately 30 days post-burst, which is consistent with
the rise-time expected for a GRB-SN at redshift z=0.49 (Cucchiara et
al., GCN 10202 & Thoene et al., GCN 10233). The observed peak magnitude
of the SN (and any underlying contribution from a host galaxy) is I~21.7.
Correcting for a small amount of Galactic reddening (A_V=0.125) and
assuming little or no host-galaxy reddening (which is consistent with the
observations of the optical afterglow of the GRB), the absolute magnitude
of this GRB-SN is V~-20.5.
Observations and analysis of this GRB-SN are ongoing.
GCN Circular 10249
Subject
GRB 091127: Skynet/PROMPT Observations of Possible Host Galaxy
Date
2009-12-05T19:43:23Z (16 years ago)
From
Josh Haislip at U.North Carolina <haislip@physics.unc.edu>
J. Haislip, D. Reichart, K. Ivarsen, A. LaCluyze, R. Egger, A. Foster, J.
Moore, A. Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M.
Nysewander report:
Skynet continued to observe the afterglow (Smith et al., GCN 10192) of GRB
091127 (Troja et al., GCN 10191) with four of the 16" PROMPT telescopes at
CTIO in BVRI (Haislip et al., GCNs 10107, 10230)
Between 4.1 and 7.3 days after the trigger, the light curve is consistent
with constant emission, which suggests that we are observing the host
galaxy.
If so, we measure its brightness to be:
I = 21.19 +/- 0.14 (statistical) +/- 0.39 (systematic; calibrated to 65
USNO B1 stars).
R = 21.27 +/- 0.13 (statistical) +/- 0.37 (systematic; calibrated to 115
USNO B1 stars).
V > 21.9 (3 sigma; calibrated to 14 NOMAD stars).
B > 21.2 (3 sigma; calibrated to 65 USNO B1 stars).
GCN Circular 10248
Subject
GRB 091127: GAO 150cm telescope Optical Observation
Date
2009-12-05T08:59:45Z (16 years ago)
From
Kenzo Kinugasa at Gunma Astro. Obs/Japan <kinugasa@astron.pref.gunma.jp>
K. Kinugasa, S. Honda, O. Hashimoto, H. Takahashi, H. Taguchi
(Gunma Astronomical Observatory) report:
The position of GRB 091127 (Troja et al., GCN 10191) was observed
with the 150 cm telescope of Gunma Astronomical Observatory.
Starting at 13:45:44 and 14:04;55 UT on Nov.28 ( about 14.3 and
14.7 hours after the trigger), Ic and Rc frames were acquired
for sets of 5 x 3-min and 5 x 3-min exposures, respectively.
We detected the optical counterpart (e.g., Smith et al., GCN 10192;
Immler et al., GCN 10193) in all frames. We estimated the Rc and Ic
magnitudes relative to USNO-B1.0 R2 and I magnitudes, respectively.
mid-UT T0+(d) exp mag.
-----------------------------------------------
13:54:51 0.6035 5x3min Rc=18.37+-0.13
14:16:39 0.6187 5x3min Ic=18.62+-0.32
-----------------------------------------------
The R magnitude is well fitted with the fading trend from the other
observations (e.g., Xu et al. GCN 10205; Sndreev et al. GCN 10207;
Haislip et al. GCN 10219).
GCN Circular 10245
Subject
GRB091127: Continuing Swift/UVOT Observations
Date
2009-12-04T14:27:58Z (16 years ago)
From
Frank Marshall at GSFC <marshall@milkyway.gsfc.nasa.gov>
F. E. Marshall (NASA/GSFC) and E. Troja (NASA/GSFC/ORAU) report on
behalf of the Swift/UVOT team:
After a relatively flat initial decay, the light curve of
the optical afterglow of GRB 091127 (Smith et al. GCN Circ. 10192;
Immler & Troja, GCN Circ. 10193) has steepened to a
decay index of 1.44 in UVOT observations with the white filter.
At 5.2 days after the BAT trigger (Troja et al., GCN Circ. 10191),
the white magnitude is 21.8 +/- 0.1.
Similar light curves are seen for the UVOT V and U filters.
The current decay index is close to that reported
by Haislip et al. (GCN Circ. 10230) using observations
between 25 and 77 hours after the trigger, and by
Cobb (GCN Circ. 10244) using data from 27.8 to 100.8
hours after the trigger.
UVOT observations of the afterglow are continuing.
GCN Circular 10244
Subject
GRB 091127, SMARTS optical/IR afterglow observations
Date
2009-12-03T23:50:51Z (16 years ago)
From
Bethany Cobb at UC Berkeley <bcobb@astro.berkeley.edu>
B. E. Cobb (UC Berkeley) reports:
Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained
optical/IR imaging of the error region of GRB 091127 (GCN 10191, Troja
et al.) over seven epochs with mid-exposure times between ~2.2 and 100.8
hours post burst.
The optical afterglow of GRB 091127 (e.g. GCN 10192, Smith et al. & GCN
10193, Immler et al., GCN 10194) is observed in our imaging. In our first
epoch, with a mid-exposure time of ~2.2 hours post-burst, the afterglow
is clearly detected in our imaging with the following magnitudes:
B = 17.21 +/- 0.02 +/- 0.20 (error in zeropoint)
R = 16.70 +/- 0.02 +/- 0.23 (error in zeropoint)
I = 16.61 +/- 0.02 +/- 0.30 (error in zeropoint)
J = 15.56 +/- 0.05
H = 15.40 +/- 0.05
K = 14.77 +/- 0.05
(Optical photometry is calibrated against USNO-B1.0 stars in the field, so
suffers from a large photometric calibration error. IR photometry is
calibrated against 2MASS stars.)
The afterglow remains visible in our optical imaging over all our epochs
of observation. Between 2.2 and 5.4 hours post burst, the afterglow decays
with a power-law of alpha ~ -0.6 (where afterglow flux is proportional
to t^alpha). From 27.8 to 100.8 hours post-burst, the afterglow appears
to have steepened its decay rate to alpha ~ -1.6. This agrees with the
behavior observed by Haislip et. al (GCNs 10219 & 10230).
mid-exposure
time (hours
post-burst) I mag
--------------------------------------------------------
2.2 16.61 +/- 0.02 [+/- 0.30, zp error]
3.8 16.90 +/- 0.02 [+/- 0.30, zp error]
5.4 17.18 +/- 0.03 [+/- 0.30, zp error]
27.8 19.28 +/- 0.03 [+/- 0.30, zp error]
30.6 19.34 +/- 0.03 [+/- 0.30, zp error]
51.7 21.10 +/- 0.12 [+/- 0.30, zp error]
100.8 21.38 +/- 0.07 [+/- 0.30, zp error]
GCN Circular 10238
Subject
GRB 091127: Zadko Telescope Observations
Date
2009-12-03T08:26:48Z (16 years ago)
From
David Coward at U of Western Aus. <coward@physics.uwa.edu.au>
T.P. Vaalsta, D.M. Coward report on behalf of the Zadko Telescope Team.
T.P. Vaalsta, D.M. Coward, I. Ward, J. Moore, A. Imerito, D. Blair,
R. Burman, S. Gordon,
A. Fletcher, A. Ahmet, A. Burrell (University of Western Australia),
L. Smith (ICRAR),
M. Todd, M. Zadnik (Curtin University),
M. Boer, M. Laas-Bourez, (OHP-OAMP),
A. Klotz, P. Thierry (CESR-OMP)
The 1.0m F/4 Zadko telescope started imaging the field of GRB 091127
(trigger=377179, D. Palmer
et al., GCN 10191) 18.5 hours after the Swift trigger. A faint source
was found at the
reported OA location (GCN 10199, S. Immler). The field was observed
for 28 minutes, during
this time the moon set and weather conditions were good.
Photometry on the co-added sum of four CCD images of total exposure
time of 806s gives
a magnitude of 18.9 +/- 0.1 for the optical counterpart.
GCN Circular 10233
Subject
GRB 091127: redshift confirmation with X-shooter
Date
2009-12-02T23:41:17Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
C.C. Thoene (INAF-OAB), P. Goldoni (APC/Univ. Paris 7 and SAp/CEA)
S. Covino (INAF-OAB), L.A. Antonelli (INAF-OAR), D. Malesani, J.P.U.
Fynbo (DARK/NBI), A.J. Levan (U. Warwick), P. Jakobsson (U. Iceland),
H. Flores (Paris Obs.), B. Milvang-Jensen, J. Hjorth, D. Watson (DARK/NBI),
K. Wiersema, N. R. Tanvir (Univ. Leicester), A. de Ugarte Postigo
(INAF-OAB) report on behalf of the X-shooter GRB collaboration:
We observed the afterglow of GRB 091127 (Troja et al. GCN 10191, Smith
et al. GCN 10192) with X-shooter at the VLT starting at 03:17 UT on
Dec 2, 2009. The observation consisted of 4x1500s exposures, with a
mean epoch 4.2 days after the burst when the magnitude of the
afterglow was R ~ 21 mag (Haislip et al. GCN 10230). We detect the
continuum in the range from 3400 to 24800 Angstrom. The S/N in the blue
part of the spectrum is low due to the effect of the nearby Moon.
In a preliminary analysis using an archival wavelength calibration we
detect several emission features superimposed on the afterglow
continuum, namely [OII] (3727, 3729), H-beta (4863), [OIII] (4960,
5007) and H-alpha (6563) at a common redshift of 0.49034 +/- 0.00018.
This redshift is consistent with the observations reported by
Cucchiara et al. (GCN 10202). We do not detect any obvious absorption
features at that redshift.
We thank the ESO observing staff, in particular H. Korhonen and S. Stefl.
GCN Circular 10230
Subject
GRB 091127: Skynet/PROMPT Continued Observations of Fading
Date
2009-12-02T17:34:10Z (16 years ago)
From
Josh Haislip at U.North Carolina <haislip@physics.unc.edu>
J. Haislip, D. Reichart, K. Ivarsen, A. LaCluyze, R. Egger, A. Foster, J.
Moore, A. Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M.
Nysewander report:
Skynet continued to observe the afterglow (Smith et al., GCN 10192) of GRB
091127 (Troja et al., GCN 10191) with four of the 16" PROMPT telescopes at
CTIO in BVRI.
The light curve (Haislip et al., GCN 10107) continued to roll over. Between
25.0 hours and 3.4 days after the trigger, the afterglow faded with a
power-law index of about -1.4 in all bands.
At 3.2 days after the trigger, the afterglow's magnitude was R = 20.71
+0.15 -0.13 (statistical) +/- 0.37 (systematic; calibrated to 102 USNO B1
stars).
Skynet's most recent BVRI light curve, calibrated to USNO B1 and NOMAD
stars, can be found here:
http://skynet.unc.edu/grb/grb091127.png
GCN Circular 10224
Subject
GRB 091127: Suzaku WAM observation of the prompt emission
Date
2009-12-01T13:01:32Z (16 years ago)
From
Yusuke Nishioka at Miyazaki U. <yusuke613@astro.miyazaki-u.ac.jp>
Y. Nishioka, H. Hayashi, N. Ohmori, A. Daikyuji,E. Sonoda, K. Kono,
K. Noda, M. Yamauchi (Univ. of Miyazaki), T. Sugasahara, M. Tashiro,
Y. Terada, A. Endo, K. Onda, W. Iwakiri (Saitama U.),
S. Sugita(Nagoya U.), K. Yamaoka (Aoyama Gakuin U.),
M. Ohno, M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA),
Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Ohmori, A. Daikyuji,
E. Sonoda, K. Kono, H. Hayashi, K. Noda, Y. Nishioka, M. Yamauchi
(Univ. of Miyazaki), N. Vasquez (Tokyo Tech.), Y. Urata, H.M Lin (NCU),
Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.),
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Hong
(Nihon U.), on behalf of the Suzaku WAM team, report
The long GRB 091127 (Swift/BAT trigger #377179 ; Stamatikos et al.,
GCN 10197; Fermi/GBM trigger #281057147 ; Colleen et al., GCN 10204)
triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an
energy range of 50 keV - 5 MeV at 2009-11-27 23:25:45.155 UT (=T0).
The observed light curve shows a double-peaked structure starting at T0 s,
ending at T0+11 s with a duration (T90) of about 7 seconds.
The fluence in 100 - 1000 keV was 7.35 (-0.50, +0.43) x10^-6 erg/cm^2.
The 1-s peak flux measured from T0+1 s was 8.94 (-0.70, +0.56)
photons/cm^2/s in the same energy range.
Preliminary result shows that the time-averaged spectrum from T0 s to
T0+11 s is well fitted by a single power-law with a photon index of
2.33 (-0.12, +0.13) (chi^2/d.o.f = 46.3/34).
All the quoted errors are at statistical 90% confidence level,
in which the systematic uncertainties are not included.
The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html
GCN Circular 10219
Subject
GRB 091127: Skynet/PROMPT Observations of Fading
Date
2009-12-01T03:28:42Z (16 years ago)
From
Josh Haislip at U.North Carolina <haislip@physics.unc.edu>
J. Haislip, D. Reichart, K. Ivarsen, A. LaCluyze, L. Cominsky, K. McLin, T.
Graves, G. Spear, R. Egger, A. Foster, J. Moore,
A. Oza, M. Schubel, J. Styblova, A. Trotter, J. A. Crain, and M. Nysewander
report:
Skynet observed the Swift/BAT localization of GRB 091018 (Troja et al., GCN
10191) with five of the 16" PROMPT telescopes at
CTIO beginning 61.6 minutes after the trigger in BVRI.
Skynet continued observing with the 14" GORT telescope at Hume Observatory
in California beginning 27.8 hours after the
trigger in RI.
We detect the afterglow (Smith et al., GCN 10192) in all filters.
Similar to GRB 091018 (LaCluyze et al., GCN 10046), the afterglow faded
more slowly in the red bands than in the blue bands
over the course of the first night.
Between 1 and 4 hours after the trigger, the afterglow faded with a
power-law index of about -0.4 in I and about -0.5 in B.
Between 4 and 9 hours after the trigger, the afterglow faded with a
power-law index of about -0.9 in I and about -1.1 in B.
Overall, I - B brightened by about 0.25 mag over the course of 8 hours.
Between 9 and 33 hours after the trigger, the afterglow faded with a
power-law index of about -1.2 in all bands.
At 32.2 hours after the trigger, the afterglow's magnitude was R = 19.39
+/- 0.06 (statistical) +/- 0.37 (systematic;
calibrated to 102 USNO B1 stars).
Skynet's most recent BVRI light curve, calibrated to USNO B1 and NOMAD
stars, can be found here:
http://skynet.unc.edu/grb/grb091127.png
GCN Circular 10211
Subject
GRB 091127: Radio observations
Date
2009-11-30T15:07:22Z (16 years ago)
From
Dale A. Frail at NRAO <dfrail@nrao.edu>
Dale A. Frail (NRAO) and Poonam Chandra (RMC) report on behalf of a
larger collaboration:
"We used the Very Large Array (VLA) to observe the field of view
towards the Swift burst GRB 091127 (GCN 10197, 10199, 10201) at a
frequency of 8.46 GHz. Data was taken at two epochs: November 29.22
and November 30.21 UT. No radio source was detected at the position of
the optical afterglow with typical 3-sigma upper limits of 300 uJy. A
bright double-radio source in the field makes deeper observations
difficult. No further observations are planned.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 10209
Subject
Konus-Wind observation of GRB 091127
Date
2009-11-30T12:11:49Z (16 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 091127 (Swift-BAT trigger #377179:
Troja et al., GCN 10191; Stamatikos et al., 10197)
triggered Konus-Wind at T0=84349.449 s UT (23:25:49.449).
The burst light curve consists of two main peaks, and a third, softer
peak. A total duration of the burst ~10 s. The Konus-Wind light
curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB091127_T84349/
As observed by Konus-Wind the burst
had a fluence of 1.22(+/-0.06)x10-5 erg/cm2,
and a 64-ms peak flux measured from T0 + 0.256s
of 8.3(+/-0.1)x10-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).
The time-integrated spectrum of the burst
(from T0 to T0+8.448 s) is well fitted
in the 20 keV - 2 MeV range by a power law
with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), with
alpha = -1.95(-0.1, +0.1),
and Ep = 21.3(-3, +4) keV (chi2 = 57/58 dof).
The spectrum of the most intense peak (measured
from T0 to T0+0.256 s) is also well fitted
in the 20 keV - 2 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.6(-0.2, +0.2),
and Ep = 130(-32, +41) keV (chi2 = 16/27 dof).
Assuming z = 0.49 (Cucchiara et al., GCN 10202) and
a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, Omega_Lambda = 0.73,
the isotropic energy release E_iso ~7.7x10^51 erg,
the peak luminosity (L_iso)_max ~7.8x10^51 erg/s.
All the quoted results are preliminary.
All the quoted errors are at the 90% confidence level.
GCN Circular 10208
Subject
GRB 091127: TAROT La Silla observatory optical observations
Date
2009-11-29T16:48:23Z (16 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz A. (CESR-OMP), Gendre B. (IASF),
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:
We imaged the field of GRB 091127 detected by Swift
(trigger 377179) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.
We performed images between
1.12 and 1.37 day after the trigger using a R filter.
We do not see the OT after co-addition of all images.
The limiting magnitude is R=20.0.
GCN Circular 10207
Subject
GRB 091127: optical observations
Date
2009-11-29T12:56:34Z (16 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
M. Andreev, A. Sergeev (Terskol Branch of Institute of Astronomy), A.
Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:
We observed the optical afterglow (Smith et al. GCN 10192) of the Swift GRB
091127 (Troja et al. GCN 10191) with the Z-600 telescope of Mt.Terskol
observatory in R-filter on Nov 28. In a combined images we clearly detect
the afterglow.
The photometry is based on the reference star used in GCN 10205 (the star
#0710-0025176 of the USNO B1 catalog, assuming R2=14.02):
T0+ Filter, Exposure, mag.
(d) (s)
0.7981 R 10x180 18.60 +/- 0.10
0.9141 R 10x180 18.90 +/- 0.15
The photometry confirms the a global decay slope of ~0.8 within the first
day after burst (Xu et al. GCN 10205).
GCN Circular 10206
Subject
GRB 091127: LABOCA/APEX submm observations
Date
2009-11-28T23:19:44Z (16 years ago)
From
Antonio Deugarte at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (INAF-OAB), A. Lundgren,
C. de Breuck, F. Montenegro and C. Agurto (ESO),
J. Gorosabel, M. Jelinek, A.J. Castro-Tirado,
P. Kubanek (IAA-CSIC), S. Covino, C.C. Thoene
(INAF-OAB) report on behalf of a larger collaboration:
"We have observed the field of GRB 091127 (Troja et al.,
GCN 10191) using LABOCA/APEX from Chajnantor (Chile) at
870 um. The observations began at 02:54 UT of the 28th
Nov (3.48 hours after the burst) and lasted for ~3 hours.
Sky conditions were mediocre, with PWV~1.5mm and
tau~0.26. The image has an r.m.s. of 4.5mJy. In the
preliminary analysis there is no source detected at the
position of the optical afterglow (Smith et al. GCN 10192).
Further observations are foreseen.
This message may be quoted."
GCN Circular 10205
Subject
GRB 091127: Further NOT optical observations
Date
2009-11-28T23:09:07Z (16 years ago)
From
Dong Xu at DARK,NBI <dong@astro.ku.dk>
D. Xu (WIS, DARK/NBI), D. Malesani, J. Hjorth (DARK/NBI), P. Jakobsson
(Univ. of Iceland), A. Carmona, C. Baldovin-Saavedra (ISDC & Geneva
Observatory) report on behalf of a
larger collaboration:
We continued to observe the field of GRB091127 (Troja et al., GCN 10191;
Smith et al., GCN 10192; Immler et al., GCN 10193) at the Nordic Optical
Telescope equipped with StanCam. Among a series of observations, a 60 s
R-band frame was obtained staring at 21:51:50 UT on Nov. 28th, 22.4347
hr after the burst trigger.
The optical afterglow is clearly detected in the frame. The magnitude is
R=18.95+/-0.04, calibrated with the reference star #0710-0025176
(R2=14.02) in the USNO B1 catalog. Comparison with our previous
observation (Xu et al., GCN 10196) indicates a decay slope of ~0.8
between the two epochs.
GCN Circular 10204
Subject
GRB 091127: Fermi GBM detection
Date
2009-11-28T22:01:05Z (16 years ago)
From
Colleen A. Wilson at NASA/MSFC/NSSTC <colleen.wilson@nasa.gov>
Colleen A. Wilson-Hodge (NASA/MSFC) and Robert D. Preece (UAH)
report on behalf of the Fermi GBM Team:
"At 23:25:45.48 UT on 27 November 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 091127 (trigger 281057147 / 091127976), which was
also detected by the SWIFT-BAT (Troja et al. 2009, GCN 10191)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 25 degrees.
The GBM light curve consists of three peaks
with a duration (T90) of about 9 s (8-1000 keV).
The time-averaged spectrum from T0+0.002 s to T0+9.984 s is
adequately fit by a Band function with Epeak = 36 +/- 2 keV,
alpha = -1.27 +/- 0.06, and beta = -2.20 +/- 0.02
(chi squared 645.8 for 445 d.o.f.).
The event fluence (8-1000 keV) in this time interval is
(1.87 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1 s in the 8-1000 keV band
is 46.9 +/- 0.9 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 10203
Subject
GRB 091127: MASTER early optical transient polarimetry
Date
2009-11-28T16:31:40Z (16 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
A.Belinski, E. Gorbovskoy, V. Lipunov,
V.Kornilov, D.Kuvshinov, N.Shatskiy, N.Tyurina, P.Balanutsa, V.V.Chazov,
D. Zemnukhov, A.Kuznetsov
Sternberg Astronomical Institute, Moscow State University
A. Tlatov, A.V. Parkhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinski, I.Zalognikh, T.Kopytova, A. Popov
Ural State University, Kourovka
S.Yazev, K.Ivanov, N.M.Budnev, E.Konstantinov, V.Lenok
Irkutsk State University
V.Yurkov
Blagoveschensk Educational State University, Blagoveschensk
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru,
D= 2x400 mm, FOV= 2x4 square degrees, 2x16 Mpx Apogee CCD) located
at Kislovodsk (2000m) was responted to the GRB 091027
(Troja et al., GCN 10191) 9 sec after Notice time and
91 s after the GRB time at very large zenit distance
(~4 degrees up to horizont).
We saw bright optical counterpart (~14 mag, 91-111 sec after GRB Time) at
Liverpool position (Smith et al., GCN 10192) in both polarizations.
We took ~20 images with synchronous exposition in two polarizations
before GRB setting with growing exposition from 20 to 160 sec.
We saw possible brightening around 2 min (after GRB Time).
The reduction is continued.
The message may be cited.
mailto: lipunov@sai.msu.ru
GCN Circular 10202
Subject
GRB 091127: Gemini-N redshift
Date
2009-11-28T11:27:46Z (16 years ago)
From
Antonino Cucchiara at PSU <cucchiara@astro.psu.edu>
A. Cucchiara, D. Fox (PSU), A. Levan (Warwick U.) and
N. Tanvir (U. Leicester) report:
On November 28.40 UT we observed the afterglow of the Swift
GRB 091127 (Troja et al. GCN 10191; Smith et al. GCN 10192)
with the GMOS-N spectrograph on Gemini North.
The observation consists of 2 exposures of 900 seconds each
with the R400 grating, covering 4000-8000A wavelength range.
The spectra shows a bright featureless continuum and two emission
lines which we identified as [OIII]4959 and 5007 respectively
at the common redshift of z = 0.490.
Therefore we suggest this as redshift for GRB 091127.
We thank the Gemini-N support staff, in particular A. Stephens,
for performing these observations.
GCN Circular 10201
Subject
GRB 091127: Swift-XRT afterglow detection and analysis
Date
2009-11-28T08:50:28Z (16 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
P.A. Evans, K.L. Page (U. Leicester) and E. Troja (NASA/GSFC/ORAU) report on
behalf of the Swift-XRT team:
We have analysed 2.4 ks of XRT data for GRB 091127 (Troja et al. GCN
Circ. 10191), from 3.2 ks to 15.8 ks after the BAT trigger. The data
comprise 761 s in Windowed Timing (WT) mode with the remainder in Photon
Counting (PC) mode. Using 1066 s of PC mode data and 4 UVOT images, we
find an enhanced XRT position (using the XRT-UVOT alignment and matching
UVOT field sources to the USNO-B1 catalogue): RA, Dec = 36.58290,
-18.95250 which is equivalent to:
RA (J2000): 02 26 19.89
Dec(J2000): -18 57 08.9
with an uncertainty of 1.4 arcsec (radius, 90% confidence). This is
consistent with the optical/UV/IR position reported in GCN Circs
10192-4.
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.09 (+/-0.05).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.97 (+/-0.08). The
best-fitting absorption column is 7.9 (+1.7, -1.6) x 10^20 cm^-2, in
excess of the Galactic value of 2.8 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.98 (+0.15, -0.14)
and a best-fitting absorption column of 9.8 (+3.3, -3.1) x 10^20 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.9 x 10^-11 (4.9 x 10^-11) erg cm^-2
count^-1.
If the light curve continues to decay with a power-law decay index of
1.09, the count rate at T+24 hours will be 0.24 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.3 x
10^-12 (1.2 x 10^-11) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00377179.
This circular is an official product of the Swift-XRT team.
GCN Circular 10200
Subject
GRB 091127: TAROT La Silla observatory optical decay
Date
2009-11-28T08:22:39Z (16 years ago)
From
Alain Klotz at CESR-CNRS <Alain.Klotz@free.fr>
Klotz A. (CESR-OMP), Gendre B. (IASF),
Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report:
We imaged the field of GRB 091127 detected by Swift
(trigger 377179) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.
The observations started 1 hour after the GRB trigger
(event occured during dusk). The elevation of the field
increased from 58 degrees above horizon and weather conditions
were good.
We detected the optical couterpart (OT) mentioned by
Smith et al. 2009 (GCNC 10192). As the OT is bright,
we used only R filtered images. We used the reference
star at coordinates 02:26:15.06 -18:54:57.3 R=15.82,
(V-R)=0.24 which is the closest star with (V-R) close
to that of the GRB (V-R~0.1 according to GROND observations
by Updike et al. GCNC 10195). The star at coodinates
02:26:21.07 -18:57:18.9 R=14.02 lies at 20 arcsec of the OT.
We substract this star before photometry:
-----------------------------------
Tstart Tstop Rmag
(min) (min)
-----------------------------------
69.12 - 82.19 16.4 +/- 0.2
106.59 - 119.67 16.7 +/- 0.3
144.33 - 157.41 16.7 +/- 0.3
182.09 - 222.83 17.0 +/- 0.2
229.91 - 346.22 17.1 +/- 0.2
367.71 - 444.61 17.4 +/- 0.2
-----------------------------------
The decay is very low since the OT decreased
of only 1 mag in 5 hours !
GCN Circular 10199
Subject
GRB 091127: Swift/UVOT observations
Date
2009-11-28T05:17:52Z (16 years ago)
From
Stefan Immler at NASA/GSFC <stefan.m.immler@nasa.gov>
S. Immler (CRESST/UMCP/GSFC) and Troja (NASA/GSFC/ORAU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 091127
3219 s after the BAT trigger (Troja et al., GCN Circ. 10191).
We detect the optical afterglow at the refined UVOT position
RA, Dec 36.58288, -18.95239, which is
RA (J2000) 02:26:19.89
Dec (J2000) -18:57:08.63
with an estimated uncertainty of 0.55 arcsec (radius, 90% confidence).
This position is consistent with ground-based optical/IR detections of
the afterglows (Smith et al., GCN 10192; Fugazza et al., GCN 10194;
Updike et al., GCN 10195; Xu et al., GCN 10196; Gorosabel et al.,
GCN 10198). Preliminary magnitudes are reported below.
Filter T_start(s) T_stop(s) Exposure(s) Mag Err
------------------------------------------------------------------------
white 3219 3369 147.4 16.2 +/- 0.1
v 3375 3575 196.6 17.0 +/- 0.1
uvw1 3785 5600 156.1 15.9 +/- 0.1
uvm2 3580 3780 196.6 15.6 +/- 0.1
-------------------------------------------------------------------------
The values quoted above are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998, ApJS, 500, 525). The photometry is on the UVOT
photometric system described in Poole et al. (2008, MNRAS, 383, 627).
GCN Circular 10198
Subject
GRB 091127: CAHA 1.23m I-band observations
Date
2009-11-28T03:25:55Z (16 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Gorosabel (IAA-CSIC), A. de Ugarte Postigo (INAF/OAB), V. Terron
(IAA-CSIC), M. Fernandez (IAA-CSIC), P. Kubanek (IAA-CSIC), M. Jelinek
(IAA-CSIC), report on behalf of a larger collaboration:
"We have detected the GRB 091127 optical afterglow (Smith et al. GCNC
10192; Immler et al. GCN 10193) by means of a single I-band frame
(Texp=120s) taken with the CAHA 1.23m Telescope. The observations,
carried out on Nov. 28.03862-28.04000 UT (~1.5 hours post burst) under
poor weather conditions, yielded a preliminary I-band magnitude of
I~16.4, assuming I=13.62 for the USNO-B1.0 star located at (RA,DEC) =
(02:26:21.063,-18:57:19.02; J2000)."
GCN Circular 10197
Subject
GRB 091127: Swift-BAT refined analysis
Date
2009-11-28T03:23:46Z (16 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), E. Troja (NASA/GSFC/ORAU), J. Tueller (GSFC),
T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 091127 (trigger #377179)
(Troja, et al., GCN Circ. 10191). The BAT ground-calculated position is
RA, Dec = 36.581, -18.948 deg, which is
RA(J2000) = 02h 26m 19.5s
Dec(J2000) = -18d 56' 51.1"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 4%.
The mask-weighted light curve shows three main peaks. The first starts
at ~T-0.3 sec and peaks at ~T0. The second peaks at ~T+1.1 sec.
The third peaks at ~T+7 sec and ends at ~T+10 sec. T90 (15-350 keV)
is 7.1 +- 0.2 sec (estimated error including systematics).
The time-averaged spectrum from T-0.4 to T+7.5 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.05 +- 0.07. The fluence in the 15-150 keV band is 9.0 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.25 sec in the 15-150 keV band
is 46.5 +- 2.7 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/377179/BA/
GCN Circular 10196
Subject
GRB 091127: NOT observations
Date
2009-11-28T03:09:15Z (16 years ago)
From
Dong Xu at DARK,NBI <dong@astro.ku.dk>
D. Xu (WIS,DARK/NBI), D. Malesani, J. Hjorth (DARK/NBI), A.A. Djupvik,
J. Datson (NOT), P. Jakobsson (Univ. of Iceland), A. Carmona, C.
Baldovin-Saavedra (ISDC & Geneva Observatory) report on behalf of a
larger collaboration:
We observed the field of GRB091127 (Troja et al., GCN 10191) with the
Nordic Optical Telescope equipped with StanCam and NOTCam, starting at
00:36:03 UT on Nov. 28th, 70.3 mins after the burst.
Preliminary data analysis confirms the bright optical afterglow (Smith
et al., GCN 10192; Immler et al., GCN 10193) and shows
R~16.3 at 00:38 UT
I~16.2 at 01:09 UT
R~16.5 at 01:15 UT
J~15.9 at 01:43 UT
H~15.4 at 01:34 UT
K~14.8 at 01:26 UT.
The R-band afterglow light curve is decaying slowly during our
observations.
GCN Circular 10195
Subject
GRB 091127 : GROND observations
Date
2009-11-28T02:17:35Z (16 years ago)
From
Andrea Rossi at TLS Tautenburg <rossi@tls-tautenburg.de>
Adria Updike (Clemson University), Andrea Rossi (Tautenburg Obs.), Arne
Rau, Jochen Greiner, Paulo Afonso and Abdullah Yoldas (all MPE Garching)
report on behalf of the GROND team:
We observed the field of GRB 091127 (Swift trigger 377179; Trojo et al.,
GCN #10191) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla
Observatory (Chile).
Observations started at 00:24 UT on Nov 28, 58 min after the GRB trigger,
and are continuing.
For the afterglow candidate reported by Smith et al. (GCN #10192) we
estimate the following preliminary magnitudes (in the AB system):
g = 16.63 +- 0.15
r = 16.53 +- 0.15
i = 16.42 +- 0.15
z = 16.35 +- 0.15
J = 16.40 +- 0.10
H = 16.36 +- 0.14
K analysis on going
Given the smal g-r color, these values are in agreement
with a afterglow at redshift z<3.5.
A second epoch, at 01:33 UT, 2h and 8 min after the burst
shows the afterglow is faded to r= 16.96+-0.15 (AB system).
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS
field stars. The errors take in account zero point uncertainties.
Magnitudes are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E_(B-V)=0.038 mag in the
direction of the burst (Schlegel et al. 1998).
GCN Circular 10194
Subject
GRB 091127: REM NIR afterglow detection
Date
2009-11-28T02:08:52Z (16 years ago)
From
Angelo Antonelli at Obs. Astro. di Roma <a.antonelli@oa-roma.inaf.it>
D. Fugazza, L.A. Antonelli, S. Covino, P. D'Avanzo, S. Campana, G. Chincarini,
V. D'Elia, F. D'Alessio, F. Fiore, P. Goldoni, C. Guidorzi, E. Maiorano, L.
Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L. Stella, G. Tagliaferri, G.
Tosti, V. Testa, S.D. Vergani, F. Vitali report on behalf of the REM team:
"The robotic 60-cm REM telescope located at La Silla (Chile) observed
automatically the field of the GRB 091127 (Troja et al. GCN 10191) on Nov 27
starting observations about 90 min after the GRB. We clearly detect a NIR source
at RA(J2000)=02:26:19.8, Dec.(J2000)=-18:57:08.3 with an uncertainty of 1" which
is compatible with the position of the optical afterglow observed for this burst
(Smith et al., GCN 10192; Immler & Troja, GCN 10193). The source was detected in
all NIR filters and showed at the observation time a magnitude H= 12.6+/-0.15
and J=13.1+/-0.23, calibrated against 2MASS. Further analysis is in progress.
This message may be citeted."
-------------------------------------------------
This mail sent through IMP: http://horde.org/imp/
GCN Circular 10193
Subject
GRB 091127: Swift/UVOT Detection of an Optical Afterglow
Date
2009-11-28T00:55:41Z (16 years ago)
From
Stefan Immler at NASA/GSFC <stefan.m.immler@nasa.gov>
GRB 091127: Swift/UVOT Detection of an Optical Afterglow
S. Immler (CRESST/UMCP/GSFC) and E. Troja (NASA/GSFC/ORAU) report
on behalf of the Swift UVOT Team:
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 3219 seconds after the BAT trigger. There is an afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 02:26:19.89 = 36.58288
DEC(J2000) = -18:57:08.5 = -18.95235
with a 90%-confidence error radius of about 0.61 arc sec. This position
is 40.9 arc sec. from the center of the BAT error circle. The estimated
magnitude is 16.21 with a 1-sigma error of about 0.14. No correction has
been made for the expected extinction corresponding to E(B-V) of 0.04.
The optical afterglow position is consistent with the Liverpool Telescope
afterglow candidate (Smith et. al GCN 10192) that was detected with a
magnitude of around R=15.0.
GCN Circular 10192
Subject
GRB 091127: Liverpool Telescope afterglow candidate
Date
2009-11-28T00:38:22Z (16 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
R.J. Smith, S. Kobayashi (Liverpool JMU), C. Guidorzi (U. Ferrara),
C.G. Mundell (Liverpool JMU) on behalf of a larger collaboration report:
"The 2-m Liverpool Telescope robotically followed up GRB 091127 (Swift
trigger 377179; Troja et al. GCN 10191) 2.35 min after the GRB trigger
time. The automatic "detection mode" procedure detected an uncatalogued
fading afterglow candidate at:
02:26:19.89 , -18:57:08.60 (J2000) uncertainty 0.5"
with magnitude of about R = 15.0 (vs USNOB1)
Observations and analysis are ongoing.
GCN Circular 10191
Subject
GRB 091127: Swift detection of a burst
Date
2009-11-27T23:36:19Z (16 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
E. Troja (NASA/GSFC/ORAU), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), J. Mao (INAF-OAB), F. E. Marshall (NASA/GSFC),
J. P. Osborne (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), J. L. Racusin (NASA/GSFC),
A. Rowlinson (U Leicester) and M. Stamatikos (OSU/NASA/GSFC) report on
behalf of the Swift Team:
At 23:25:45 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 091127 (trigger=377179). Swift did not immediately slew
to the burst due to Earth limb constraint.
The BAT on-board calculated location is
RA, Dec 36.571, -18.954 which is
RA(J2000) = 02h 26m 17s
Dec(J2000) = -18d 57' 12"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multi-peaked
structure with a duration of about 10 sec. The peak count rate
was ~30,000 counts/sec (15-350 keV), at ~1 sec after the trigger.
Due to an observing constraint, Swift will not slew until
T0+50 minutes. There will be no XRT or UVOT data until
this time.
Burst Advocate for this burst is E. Troja (eleonora.troja AT nasa.gov).
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.)