GRB 170121B
GCN Circular 20516
Subject
GRB 170121B: AbAO optical observations
Date
2017-01-24T17:41:03Z (9 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), A. Pozanenko (IKI), R. Inasaridze (AbAO), A. Volnova
(IKI), V. Ayvazian (AbAO), O.Kvaratskhelia (AbAO), G. Inasaridze (AbAO),
I. Molotov (KIAM), report on behalf of larger GRB follow-up collaboration:
We observed the field of optical transient reported by Lipunov et al. (GCN
20502) as a possible candidate of the Fermi/GBM GRB 170121B (Hamburg et al.
GCN Circ. 20505) and XRT afterglow candidate reported by Sbarufatti et
al. (GCN 20510) with AS-32 (0.7m) telescope of Abastumani Observatory
starting on Jan., 23 (UT) 16:14:49. We obtained several unfiltered images
of the field. We do not find any source at coordinates of the optical
transient (Lipunov et al., GCN 20502). Within XRT error circle (Sbarufatti
et al., GCN 20510) we find the source which is also presented in DSS2 and
USNO-B1.0 as the star USNO-B1.0 0807-0048671 (magnitudes R1 = 17.94, R2 =
17.07). Preliminary photometry of the source and the field of the optical
transient (Lipunov et al., GCN 20502) is following
Date UT start t-T0 Filter Exp. OT Err UpLim (3 sigma)
(mid, days) (s)
2017-01-23 16:14:49. 2.09866 CR 60*60 17.76 0.07 22.9
Photometry is based on nearby USNO-B1.0 stars (R2 magnitudes)
USNO-B.1_id R2
0807-0048576 16.37
0806-0049543 18.47
0807-0048525 17.28
0807-0048536 17.23
0806-0049637 15.57
0807-0048826 15.71
0807-0048833 15.41
0807-0048816 17.22
GCN Circular 20514
Subject
GRB 170121B: MASTER early optical observations of the Swift possible XT
Date
2017-01-24T14:05:20Z (9 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, E.Popova, N.Tyurina, V.Kornilov, D.Kuvshinov,
N.Tyurina, A.V.Krylov, I.Gorbunov, P.Balanutsa,
A.Kuznetsov, V.V.Chazov, D.Vlasenko
Lomonosov Moscow State
University, Sternberg Astronomical Institut of MSU
V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
O. Ershova
Irkutsk State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
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
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in
Blagoveschensk was pointed to the Fermi trigger Number 506702667
(Hamburg et al., 20505) 72 sec
after notice time and 171 sec after trigger time at 2017-01-21 14:47:14 UT.
MASTER-Amur auto-detection system discovered MASTER OT J045017.73-091602.0
with unfiltered magnitude is 14.9m (limit 16.0 m) (Lipunov et al., GCN 20502).
We do not see any optical source at Swift XRT position (Sbarufatti et
al., GCN 20510) with next limits:
Date UT Exp Type Limit
start
2017-01-21 14:50:48 60 Alert (FERMI) 16.6
2017-01-21 14:49:21 60 Alert (FERMI) 16.1
2017-01-21 14:48:11 40 Alert (FERMI) 16.4
2017-01-21 14:47:14 30 Alert (FERMI) 16.0
2017-01-21 14:46:28 20 Alert (FERMI) 16.0
The message may be cited.
GCN Circular 20511
Subject
GRB 170121B: AstroSat CZTI detection
Date
2017-01-23T17:18:36Z (9 years ago)
From
Vidushi Sharma at IUCAA <vidushi@iucaa.in>
V.Sharma, D. Bhattacharya and V. Bhalerao (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:
Analysis of AstroSat CZTI data showed clear detection of GRB170121B (Fermi GBM detection: R.Hamburg et al., GCN Circ. 20505) in the 40-200 keV energy range. The light curve shows two peaks structure with brightest peak at 14:44:31.41 UT, 9 seconds after the Fermi trigger. The measured peak count rate is 320.2 counts/sec above the background in combined data of four quadrants, with a total of 4185.9 counts. The local mean background count rate was 344.2 counts/sec. Using cumulative rates, we measure a T90 of 28.3 secs.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb . CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN Circular 20510
Subject
GRB 170121B: Swift-XRT and UVOT observations
Date
2017-01-23T14:53:39Z (9 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A.P. Beardmore (U.
Leicester), S.L. Gibson (U. Leicester), A. D'Ai (INAF-IASFPA), A.
Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), A. Cholden-Brown (PSU),
P.A. Evans (U. Leicester) and A.A. Breeveld (UCL-MSSL) report on behalf
of the Swift team:
Swift-XRT has performed follow-up observations of the optical transient
reported by Lipunov et al. (GCN Circ. 20502) as a possible candidate
afterglow of the Fermi/GBM-detected burst GRB 170121B (Hamburg et al.
GCN Circ. 20505), collecting 4.5 ks of Photon Counting (PC) mode data
between T0+124.0 ks and T0+147.4 ks.
No X-ray sources have been detected at the position of the optical
transient reported by Lipunov et al. (GCN Circ. 20502).
An uncatalogued X-ray source is detected within the XRT field of view
at the position RA, Dec 72.6361, -9.2424 which is equivalent to:
RA(J2000) = 04h 50m 32.66s
Dec(J2000) = -09d 14' 32.5"
with an uncertainty of 2.7 arcseconds (radius, 90% containment). The
source has a 0.3-10 keV count rate of about 9e-3 ct/sec. We cannot
determine fading at this time.
The 3-sigma upper limit in the field ranges from ~2e-3 to ~3e-3 ct
s^-1, corresponding to a 0.3-10 keV observed flux of 6.5e-14 to 1.0e-13
erg cm^-2 s^-1 (assuming a typical GRB spectrum).
The results of the XRT-team automatic analysis of the XRT observations,
including a position specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020729.
The Swift/UVOT began settled observations 124 ks after the trigger
(Hamburg et al, GCN Circ. 20505). Summing up the early white data at
the position of the OT found by Lipunov et al. (GCN Circ. 20502) we do
not find any source to an upper limit of 22.2 mags in 3430s.
At the position of the new uncatalogued XRT source described above we
do see a source already listed in the USNO-B1.0 catalogue and it is not
fading.
This circular is an official product of the Swift team.
GCN Circular 20508
Subject
GRB 170121B: LCO FTN observations
Date
2017-01-23T08:41:54Z (9 years ago)
From
Cristiano Guidorzi at Ferrara U,Italy <guidorzi@fe.infn.it>
C. Guidorzi (U. Ferrara), S. Kobayashi, I.A. Steele (LJMU), A. Gomboc
(U. Nova Gorica), C.G. Mundell (U. Bath) on behalf of a large
collaboration report:
We observed Fermi GRB 170121B (Hamburg et al. GCN 20505) on January 23,
07:21 UT (1.7 days since the GRB) with the 2-m LCO Faulkes Telescope
North in Hawaii with SDSS r and i filters. We do not detect the MASTER
optical counterpart (Lipunov et al. GCN 20502) down to the following limits:
Mid Time Exposure Filter Magnitude (AB)
(days) (s)
-------------------------------------------------------
1.69 2x120 SDSS-R > 21.0
1.69 2x120 SDSS-I > 19.5
-------------------------------------------------------
as calibrated against nearby USNO-URAT1 sources.
GCN Circular 20505
Subject
GRB 170121B: Fermi GBM detection
Date
2017-01-23T01:04:55Z (9 years ago)
From
Rachel Hamburg at UAH <rkh0007@uah.edu>
R. Hamburg (UAH), C. Meegan (UAH), and P. Veres (UAH)
report on behalf of the Fermi GBM Team:
"At 14:44:22.41 UT on 21 January 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170121B (trigger
506702667 / 170121614).
It may be noted that this burst is distinct from GRB 170121A
(trigger 506655418 / 170121067), which was also detected by POLAR
(H.L. Xiao et al. 2017, GCN 20501).
A potential optical counterpart to GRB 170121B was detected
by MASTER, although it was referenced as GRB 170121A
(V. Lipunov et al. 2017, GCN 20502).
The on-ground calculated location, using the GBM trigger
data, is RA = 72.84, DEC = -12.65, with an uncertainty
of 1.78 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).
The angle from the Fermi LAT boresight at the GBM trigger time is 74
degrees.
The GBM light curve shows two main peaks
with a duration (T90) of about 46 s (50-300 keV).
The time-averaged spectrum from T0-2.05 s to T0+43.01 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.00 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 455.90 +/- 27.70 keV.
The event fluence (10-1000 keV) in this time interval is
(2.97 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+24.6 s in the 10-1000 keV band
is 9.4 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
[GCN OPS NOTE(23jan17), Per author's request, the Subject and first sentence
were changed from "160121B" to "170121B".]
GCN Circular 20504
Subject
GRB 170121B: Swift ToO observations
Date
2017-01-23T00:49:18Z (9 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Fermi/GBM GRB 170121B.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020729
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Fermi/GBM event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a
GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular 20502
Subject
GRB 170121B/Fermi trigger 506702667 MASTER-Amur OT detection
Date
2017-01-22T22:22:36Z (9 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, E.Popova, N.Tyurina, V.Kornilov,
D.Kuvshinov, N.Tyurina, A.V.Krylov, I.Gorbunov, P.Balanutsa,
A.Kuznetsov, V.V.Chazov, D.Vlasenko
Lomonosov Moscow State
University, Sternberg Astronomical Institut of MSU
V.Yurkov, Yu.Sergienko
Blagoveschensk Educational State University, Blagoveschensk
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk,
O. Ershova
Irkutsk State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
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
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Blagoveschensk was pointed to the Fermi trigger Number
506702667 72 sec after
notice time and 171 sec after trigger time at 2017-01-21 14:47:14 UT.
MASTER-Amur auto-detection system discovered OT source at (RA, Dec) = 04h
50m 17.73s -09d 16m 02.0s .
The OT unfiltered magnitude is 14.9m (limit 16.0 m).
The OT is seen in 5 images. OT detected before maximum and shown decay on
last images 4 minutes after detection.
We have reference image without OT on 2017-01-21.61560 UT with unfiltered
magnitude limit 20.5 m.
Spectral observations are required.
The message may be cited.
[GCN OPS NOTE(23jan17): Per author's request, the Subject line was corrected
from "170121A" to "170121B".]