GRB 171209A
GCN Circular 22360
Subject
Konus-Wind observation of GRB 171209A
Date
2018-01-17T13:39:48Z (8 years ago)
From
Anna Kozlova at Ioffe Institute <ann_kozlova@mail.ioffe.ru>
A.Kozlova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko,
and T. Cline on behalf of the Konus-Wind team, report:
The long GRB 171209A (Swift-BAT trigger #796100: LaPorte et al.,
GCN 22213; Cummings et al., GCN 22229)
was detected by Konus-Wind (KW) in the waiting mode.
The burst light curve shows a multi-peaked structure
with a duration of ~ 147 s.
As observed by KW, the burst had a fluence of
1.56(-0.17,+0.16)x10^-5 erg/cm2 and a 2.944-s peak flux,
measured from ~T0(BAT)+22.4 s, of 3.06(-0.62,+0.61)x10^-7 erg/cm2/s
(both in the 20 - 10000 keV energy range).
Modeling the KW 3-channel time-integrated spectrum
(from ~T0(BAT)-1.2 s to ~T0(BAT)+146 s)
by a power law with exponential cutoff model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.13 (-0.23,+0.40), and Ep = 279 (-86,+141) keV.
The KW light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB171209A/
All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.
GCN Circular 22237
Subject
GRB 171209A: MASTER-Net optical observations
Date
2017-12-11T14:05:44Z (8 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
E. Gorbovskoy, V. Lipunov, V.Kornilov, N.Tyurina,
D.Kuvshinov, A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov,
D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU
R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA),
National University of San Juan, Argentina
H. Levato, C. Saffe
Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE),
San Juan, Argentina
D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias
O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
Irkutsk State University
V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in OAFA was starting survey on the SWIFT GRB171209A error-box
(LaPorte et al. GCN 22213) 44912 sec after notice time and 44965 sec
after trigger time at 2017-12-10 03:15:41 UT. The 5-sigma upper limit on
our single (180s exposure) set is about 19.4-m and 20.0-m on coadd
(3x180 = 540s) image. We not see OT previously reported by Kuin et al. GCN
22221 , Guidorzi et al. GCN 22214 , Kong et al. GCN 22230.
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in SAAO was starting survey on the SWIFT GRB171209A 114607
sec (~ 32 hours) after trigger time at 2017-12-10 03:15:41 UT. The
5-sigma upper limit on our single (180s exposure) set is about 19.4-m
and 20.5-m on coadd (10 x 180 = 1800 s) image. Here we also not see any
OT.
This message can be cited.
GCN Circular 22230
Subject
GRB 171209A: Lulin 1m telescope observations
Date
2017-12-10T17:59:29Z (8 years ago)
From
Albert Kong at NTHU <akhkong@gmail.com>
GRB 171209A: Lulin 1m telescope observations
A.K.H. Kong (NTHU, Taiwan) reports
We observed the field of GRB 171209A (LaPorte et al. GCN 22213) with
the 1m telescope at the Lulin Observatory in Taiwan. The observations
were done with the SDSS r and i filters and the first observation were
started at 2017-12-09 20:20:16 UT (5.6 hours post burst). We detect
the optical afterglow identified by the UVOT and LCO (Guidorzi et al.
GCN 22214). We obtained the following magnitudes:
Start time Exposure Filter Magnitude (AB)
20:20:16 300s SDSS-r 19.47+/-0.11
20:25:50 300s SDSS-i 18.97+/-0.09
The magnitudes were calibrated with nearby Pan-STARRS objects.
GCN Circular 22229
Subject
GRB 171209A: Swift-BAT refined analysis
Date
2017-12-10T17:50:20Z (8 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
J. R. Cummings (CPI), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF/USRA), S. J. LaPorte (PSU),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+400 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 171209A (trigger #796100)
(LaPorte et al., GCN Circ. 22213). The BAT ground-calculated position is
RA, Dec = 139.387, -30.523 deg which is
RA(J2000) = 09h 17m 32.8s
Dec(J2000) = -30d 31' 22.4"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 61%.
The mask-weighted light curve shows a multi-peaked structure that starts at
~ T-70 s and ends at ~ T+230 s. T90 (15-350 keV) is 161.7 +- 30.8 sec (estimated
error including systematics).
The time-averaged spectrum from T-70.76 to T+228.44 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.58 +- 0.07. The fluence in the 15-150 keV band is 7.5 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+79.52 sec in the 15-150 keV band
is 1.6 +- 0.2 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/796100/BA/
GCN Circular 22221
Subject
GRB 171209A: Swift/UVOT Analysis of the burst
Date
2017-12-10T02:13:55Z (8 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and and S. J. LaPorte (PSU) report on
behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 171209A
107 s after the BAT trigger (LaPorte et al., GCN Circ. 22213).
The proposed possible transient position was confirmed by independent
observations of the LCO telescopes in Siding Springs in the SDSS r and
i filters (Guidorzi et al, GCN Corc. 22214) and by the XRT (d'Avanzo
et al. GCN Circ. 22218).
Due to the nearby star (at 3.7"), the count rates were determined using
a smaller than normal aperture of 2.5 arcsec, and for the reported
magnitudes no aperture correction has been applied.
The brightness is seen to rise to 16th magnitude around 400s past the
trigger at which time there is a break in the UVOT observations until
4000s past the trigger at which time the source is seen to be decaying.
After binning the white filter data in 10s bins, half a magnitude large
variability is seen up to 175s after the trigger.
There is no measurable flux in the uvw1,uvm2, and uvw1 filters
which were observed after the gap, which suggests a redshifted source
with a redshift in the range z = 1.8 - 2.8.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 175 185 541 17.4
v 4630 6265 393 17.3
b 4014 5649 393 18.2
u 320 350 30 16.5
w1 5039 6480 201 >19.6
m2 4834 6470 393 >20.2
w2 4425 6060 393 >20.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.15 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 22219
Subject
GRB 171209A: Swift-XRT refined Analysis
Date
2017-12-09T22:25:41Z (8 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), S.L. Gibson (U.
Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), P.
D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A.
Tohuvavohu (PSU) and S.J. LaPorte report on behalf of the Swift-XRT
team:
We have analysed 6.3 ks of XRT data for GRB 171209A (LaPorte et al. GCN
Circ. 22213), from 92 s to 17.9 ks after the BAT trigger. The data
comprise 349 s in Windowed Timing (WT) mode (the first 5 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. Using 2454 s of PC mode data and 6 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 = 139.40280, -30.52016
which is equivalent to:
RA (J2000): 09h 17m 36.67s
Dec(J2000): -30d 31' 12.6"
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=1.87 (+/-0.08). At T+231 s the decay
steepens to an alpha of 3.42 (+0.26, -0.22) before breaking again at
T+629 s to a final decay with index alpha=0.74 (+0.12, -0.11).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.37 (+/-0.04). The
best-fitting absorption column is 2.54 (+0.27, -0.25) x 10^21 cm^-2,
in excess of the Galactic value of 2.1 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.06 (+0.08, -0.07)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.4 x 10^-11 (4.5 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 2.11 (+0.10, -0.00) x 10^21 cm^-2
Galactic foreground: 2.1 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 2.06 (+0.08, -0.07)
If the light curve continues to decay with a power-law decay index of
0.74, the count rate at T+24 hours will be 0.036 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-12 (1.6 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00796100.
This circular is an official product of the Swift-XRT team.
GCN Circular 22218
Subject
GRB 171209A: Enhanced Swift-XRT position
Date
2017-12-09T19:57:15Z (8 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D���Avanzo, A. Melandri (INAF-OAB), J. A. Kennea (PSU), P.A. Evans
and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team:
Using 2454 s of XRT Photon Counting mode data and 6 UVOT
images, 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 = 139.40280, -30.52016 which is equivalent to:
RA (J2000): 09 17 36.67
Dec (J2000): -30 31 12.6
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position is consistent with the one reported for the Swift/UVOT
candidate (LaPorte et al., GCN 22213).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions <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 is an official product of the Swift-XRT team.
GCN Circular 22214
Subject
GRB 171209A: LCO 1-m telescope observations
Date
2017-12-09T18:11:27Z (8 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath),
A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large
collaboration report:
We observed Swift GRB171209A (LaPorte et al. GCN 22213) on December 9,
16:25 UT (1.65 hours post burst) with one of the 1-m LCO telescopes in
Siding Springs in the SDSS ri filters. We detect the UVOT candidate,
which is not visible in archival Pan-STARRS images, with the following
magnitudes:
Mid Time�������� Exposure�������������� Filter�������� Magnitude (AB)
(hr)�������������������� (s)
------------------------------------------------------
1.69������������������ 2x120������������������ SDSS-R������������ 18.2 +- 0.3
1.78������������������ 2x120������������������ SDSS-I������������ 17.8 +- 0.3
------------------------------------------------------
as calibrated against nearby Pan-STARRS objects. Due to the vicinity of
(~4") of a bright object, our estimated magnitudes are to be taken
cautiously.
GCN Circular 22213
Subject
GRB 171209A: Swift detection of a burst
Date
2017-12-09T15:30:16Z (8 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
S. J. LaPorte (PSU), D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB),
S. W. K Emery (UCL-MSSL), J.D. Gropp (PSU), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), A. Melandri (INAF-OAB) and
D. M. Palmer (LANL) report on behalf of the Swift Team:
At 14:46:16 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 171209A (trigger=796100). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 139.382, -30.528 which is
RA(J2000) = 09h 17m 32s
Dec(J2000) = -30d 31' 38"
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 100 sec. The peak count rate
was ~1300 counts/sec (15-350 keV), at ~80 sec after the trigger.
UVOT took a finding chart exposure of 194 seconds with the U filter starting
265 seconds after the BAT trigger. No credible afterglow candidate has been
found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the
BAT error circle. The typical 3-sigma upper limit has been about 19.2 mag. The
8'x8' region for the list of sources generated on-board covers 98% of the BAT
error circle. The list of sources is typically complete to about 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.15.
However, a possible candidate source of magnitude 17.3 in white is present at
RA(J2000) = 09h 17m 36.70s
Dec(J2000) = -30d 31m 12.0s
which is very close to two other sources in the DSS survey image.
The XRT detected the afterglow from this GRB. However, due to data
transmission problems, an XRT position will not be available until
more data is transmitted to the ground.
Burst Advocate for this burst is S. J. LaPorte (extragsam 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.)