GRB 181201A
GCN Circular 23469
Subject
GRB 181201A: a long GRB detected by INTEGRAL
Date
2018-12-01T03:43:01Z (7 years ago)
From
Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti@inaf.it>
S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo,
V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix)
and J.Borkowski (CAMK, Torun) report:
a gamma ray burst lasting about 180 s has been detected by IBAS in the
IBIS/ISGRI data at 02:38 UT of 1 December 2018
The refined coordinates (J2000) are:
R.A.= 319.3009 deg
DEC.= -12.6242 deg
with an uncertainty of 2 arcmin (90% c.l.).
The burst was bright and saturated the telemetry. Therefore, we can only
give lower limits to its peak flux of greater than 2 counts/cm2/s (20-200
keV, 1-s integration
time) and a fluence in the same energy range of more than 1e-4 erg/cmq.
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular 23470
Subject
GRB 181201A MASTER-Net OT detection
Date
2018-12-01T10:15:47Z (7 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
R. Podesta, Carlos Lopez and F. Podesta
Observatorio Astronomico Felix Aguilar (OAFA)
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa,
A.Kuznetsov, V.V.Chazov, A.V. Krylov, I. Gorbunov, D. Vlasenko
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk
K. Ivanov, O. Gres, N.M. Budnev, S.Yazev, O. Chuvalaev, V. Poleshchuk
Irkutsk State University
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-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov
et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA
observatory of San Juan National University) was pointed to the GRB181201.11
10 sec after notice time and 18 sec after trigger time at 2018-12-01 02:40:30
UT. On our first (10s exposure) set we found 1 optical transient within
INTEGRAL error-box (ra=319.317 dec=-12.6325 r=0.05) brighter than 16.2.
T-Tmid Date Time Expt. Ra Dec Mag
-------|---------------------|-------|-----------------|-----------------|------
23 2018-12-01 02:40:30 10 ( 21h 17m 11.2s , -12d 37m 51.4s) |13.17
The 5-sigma upper limit has been about 16.2mag
The message may be cited.
====================================================================
The galactic latitude b = -39 deg., longitude l = 39 deg.
The observations made on zenit distance = 76 deg.The moon (38 % bright part)
below the horizon (The altitude of the Moon is -41 deg. ).
The sun altitude is -30.9 deg.
The object can be observed till 2018-12-01 03:49:27
GCN Circular 23471
Subject
GRB 181201A: likely Swift/XRT afterglow
Date
2018-12-01T10:23:45Z (7 years ago)
From
Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti@inaf.it>
S.Mereghetti, F.Pintore (IASF-Milano), D.Gotz (CEA, Saclay),
C.Ferrigno, E.Bozzo,
V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix)
and J.Borkowski (CAMK, Torun) report:
The Swift XRT observed the position of GRB181201A starting 4 hr after the
INTEGRAL trigger time, from 6:33 UT to 7:06 UT.
A possibly fading X-ray source with count rate of 2.38+/-0.04 ct/s is
detected inside the IBAS error circle at coordinates
R.A. = 21 17 11
Dec.= -12 37 48
[GCN OPS NOTE(01dec18): Per author's request, indentification name of the burst
was changed from "GRB 180112A" to "GRB 181201A" in both the SUBJECT line
and in the first sentence of the circular.]
GCN Circular 23472
Subject
GRB 181201A: Swift-XRT afterglow
Date
2018-12-01T12:12:37Z (7 years ago)
From
Sandro Mereghetti at IASF-Milano/INAF <sandro.mereghetti@inaf.it>
F.Pintore, S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno,
E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC,
Versoix)
and J.Borkowski (CAMK, Torun) report:
Swift/XRT observed the position of GRB181201A on 1 December 2018 from 6:33
UT to 7:06 UT (GCN #23471), in PC mode.
The XRT data show that the X-ray source reported by Mereghetti et al. (GCN
Circ. n. 23471 ) is fading and has an average spectrum well modelled by a
single absorbed powerlaw. The best-fit parameters are: column density of (6
+\- 2)x10^20 cm-2, consistent with the Galactic column density (5.2e20
cm-2, Willingale et al.2013), photon index of 1.76 +\- 0.08. The average
0.3-10 keV absorbed flux is (1.06 +\- 0.06)x10^-10 erg cm-2 s-1.
The time decay is well modeled with a power law of index 1.2 +\- 0.1
GCN Circular 23473
Subject
GRB 181201A: Swift ToO observations
Date
2018-12-01T13:45:27Z (7 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 INTEGRAL GRB 181201A.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020848
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 INTEGRAL 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 23474
Subject
GRB 181201A: Swift-XRT afterglow detection
Date
2018-12-01T14:17:02Z (7 years ago)
From
Kim Page at U.of Leicester <klp5@leicester.ac.uk>
K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia
(ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), S. J. LaPorte
(PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU) and P.A. Evans
(U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the INTEGRAL-detected
burst GRB 181201A (Mereghetti et al. GCN Circ. 23469), collecting 5.0
ks of Photon Counting (PC) mode data between T0+14.3 ks and T0+26.4 ks.
Five uncatalogued X-ray sources are detected, of which one ("Source 5")
is above the RASS limit, and is therefore likely the GRB afterglow.
Using 4968 s of PC mode data and 3 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 = 319.29666, -12.63082 which is
equivalent to:
RA (J2000): 21h 17m 11.20s
Dec(J2000): -12d 37' 51.0"
with an uncertainty of 2.0 arcsec (radius, 90% confidence). This
position is 28 arcsec from the INTEGRAL position.
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.44 (+/-0.18).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.74 (+0.08, -0.07). The
best-fitting absorption column is 6.1 (+2.0, -0.9) x 10^20 cm^-2,
consistent with the Galactic value of 5.2 x 10^20 cm^-2 (Willingale et
al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum is 3.8 x 10^-11 (4.2 x
10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 6.1 (+2.0, -0.9) x 10^20 cm^-2
Galactic foreground: 5.2 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.74 (+0.08, -0.07)
If the light curve continues to decay with a power-law decay index of
1.44, the count rate at T+24 hours will be 0.30 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-11 (1.3 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/00020848.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020848.
This circular is an official product of the Swift-XRT team.
GCN Circular 23475
Subject
GRB 181201A: iTelescope optical afterglow detection
Date
2018-12-01T15:48:16Z (7 years ago)
From
Albert Kong at NTHU <akhkong@gmail.com>
A.K.H. Kong (NTHU, Taiwan)
We observed the field of GRB 181201A (Mereghetti et al. GCN 23469)
with the T31 0.5m telescope of iTelescope.Net in Siding Spring,
Australia. The observation was done with the R-band filter beginning
at 2018-12-01 10:56:18 UT (8.3 hours after the INTEGRAL trigger) for
300 sec. At the position of the Swift X-ray afterglow (Mereghetti et
al. GCN 23471; Page et al. GCN 23474), an optical transient is clearly
detected with a R magnitude of 16.68 +/- 0.03 by comparing with the
USNO-B1 catalogue. The position is also consistent with the optical
transient detected by Podesta et al. (GCN 23470) 18 sec after the
trigger. Given the fading of the optical brightness, this transient is
the optical afterglow of GRB 181201A.
GCN Circular 23476
Subject
GRB 181201A MASTER-Net OT continued observation
Date
2018-12-01T17:24:28Z (7 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina,
P.Balanutsa,
A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk
Irkutsk State University
V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk
R. Podesta, Carlos Lopez and F. Podesta
Observatorio Astronomico Felix Aguilar (OAFA)
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias
D. Buckley, S. Potter, A. Kniazev, M. Kotze
South African Astronomical Observatory
MASTER-Kislovodsk robotic telescope (MASTER-Net:
http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy,
vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station
of Pulkovo observatory) was pointed to the GRB181201A (Mereghetti et
al., GCN #23469) ~13.3 hours after trigger time at 2018-12-01 15:57:35 UT.
On our first (180s exposure) set we found optical transient detected
by MASTER-OAFA (Podesta et al, GCN 23470; Gorbovskoy et al., Atel
#12255; also observed by Kong GCN #23475;).
T-Tmid Date Time Expt. Ra Dec Mag
---------|---------------------|-------|-----------------|-----------------|-------
47915s 2018-12-01 15:57:35 180 (21h 17m 11.11s , -12d 37m 50.9s) 17.6
The 5-sigma upper limit has been about 18.3 mag
The galactic latitude b = -39 deg., longitude l = 39 deg.
The observations made on zenit distance = 64 deg.The moon (32 % bright
part) below the horizon (The altitude of the Moon is -41 deg. ).
The sun altitude is -25.6 deg.
The object can be observed till sunrise at 2018-12-02 04:21:42 UT.
The message may be cited.
GCN Circular 23477
Subject
GRB 181201A: optical observations in SAAO
Date
2018-12-01T20:06:16Z (7 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), E. Mazaeva (IKI), D. Buckley (SAAO), A. Pozanenko
(IKI) report on behalf of IKI-FuN follow-up collaboration:
We observed the field of the INTEGRAL GRB 181201A (Mereghetti et al.,
GCN 23469) with 1m telescopes of SAOO observatory. Observation started
on Dec. 01 (UT) 18:34:35 in g'Ri'-filters. We detected optical
afterglow (Podesta et al., GCN 23470; Kong GCN 23475). Preliminary
photometry is following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2018-12-01 18:34:35 0.66950 g' 5*180 17.86 0.02
2018-12-01 18:52:05 0.67992 R 5*120 17.38 0.02
2018-12-01 19:02:35 0.68721 i' 5*120 17.32 0.02
The photometry is based on SDSS DR12 nearby stars.
GCN Circular 23478
Subject
GRB 181201A: NOT optical observations
Date
2018-12-01T21:41:15Z (7 years ago)
From
Kasper Elm Heintz at Univ. of Iceland and DAWN/NBI <keh14@hi.is>
Kasper E. Heintz (Univ. of Iceland), Daniele B. Malesani (DAWN/NBI and DARK/NBI), and Shane Moran-Kelly (Univ. of Turku and NOT), report on behalf of a larger collaboration:
We observed the optical afterglow (Podesta et al., GCN 23470; Kong, GCN 23475; Lipunov et al., GCN 23476: Volnova et al., GCN 23477) of the INTEGRAL GRB 181201A (Mereghetti et al., GCN 23469) with the 2.5-m Nordic Optical Telescope (NOT) equipped with StanCam.
Observations were carried out in the Bessel R filter, but calibrated against SDSS r-band Pan-STARRS local photometry, corrected to the R-band using the Lupton transformation. At a mid-time of 20:27:09 UT on December 1 (i.e. 17.8 hr after trigger) we measure for the optical counterpart: r = 17.5 +/- 0.1 AB mag, where the error is dominated by scatter in the preliminary calibration.
GCN Circular 23479
Subject
GRB 181201A: Zeiss-1000/CrAO optical observations
Date
2018-12-01T23:21:37Z (7 years ago)
From
Alina Volnova at SAI MSU <alinusss@gmail.com>
E. Mazaeva (IKI), A. Volnova (IKI), A. Pozanenko (IKI), I. Nikolenko
(CrAO),
A. Novichonok (KIAM, PetrSU), I. Molotov (KIAM)
report on behalf of larger GRB follow-up collaboration:
We observed the field of the INTEGRAL GRB 181201A (Mereghetti et al.,
GCN 23469) with Zeiss-1000/Koshka (CrAO) telescope starting Dec 01,
16:55:28 UT. We obtained several frames in R filter. The optical
afterglow (Podesta et al., GCN 23470; Kong, GCN 23475) is clearly
detected in the stacked frame. Preliminary photometry is following:
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2018-12-01 16:55:28 0.60359 R 23*60 17.17 0.05
The photometry is based on SDSS DR12 nearby stars.
GCN Circular 23480
Subject
GRB 181201A: Fermi-LAT detection
Date
2018-12-02T02:41:40Z (7 years ago)
From
Magnus Axelsson at Stockholm U. <magaxe@kth.se>
M. Arimoto (Kanazawa U.), M. Axelsson (KTH & Stockholm Univ.), and M. Ohno (Hiroshma U.) report on behalf of the Fermi-LAT team:
On December, 01, 2018, Fermi-LAT detected high-energy emission from GRB 181201A, which was also detected by INTEGRAL (Mereghetti et al., GCN 23469) and Swift/XRT (Pintore et al., GCN 23472).
The best LAT on-ground location is found to be
RA, Dec = 319.28, -12.60 (degrees, J2000)
with an error radius of 0.06 deg (90% containment, statistical error only).
This was 131 deg from the LAT boresight at the time of the INTEGRAL trigger:
T0 = 02:38:00 UT
and entered the LAT field of view ~2000 seconds later.
The data from the Fermi-LAT show a significant increase in the event rate that is spatially correlated with the INTEGRAL source (0.03 degrees from the INTEGRAL location) with high significance. The photon flux above 100 MeV in the time interval 2000-10000 s after the INTEGRAL trigger is (4.5 +/- 3.3) E-7 ph/cm2/s.
The estimated photon index above 100 MeV is -1.32+/-0.39.
The highest-energy photon is a 25.5 GeV event which is observed ~7600 seconds after the INTEGRAL trigger.
The Fermi-LAT point of contact for this burst is Masanori Ohno (ohno@astro.hiroshima-u.ac.jp<mailto:ohno@astro.hiroshima-u.ac.jp>).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular 23481
Subject
GRB 181201A: COATLI Optical Detection
Date
2018-12-02T06:37:42Z (7 years ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Margarita Pereyra (UNAM), Nat Butler (ASU), Rosa
L. Becerra (UNAM), William H. Lee (UNAM), Carlos Rom��n-Z����iga (UNAM),
Alexander Kutyrev (GSFC), and Eleonora Troja (GSFC), report:
We observed the field of GRB 181201A (Mereghetti et al., GCN 23469) with
the COATLI 50-cm telescope and interim imager at the Observatorio
Astron��mico Nacional on the Sierra de San Pedro M��rtir
(http://coatli.astroscu.unam.mx) from 2018-12-02 01:39:01 to 04:02:58
(from 23.0 to 25.4 hours after the trigger), obtaining a total of 1.89
hours of exposure in the w filter.
We detect the optical counterpart reported by Podesta et al. (GCN Circ.
23470) at w = 17.82 +/- 0.01.
Our w magnitudes are calibrated against the USNO-B1 catalog (adjusted to
an approximate AB system) and are not corrected for Galactic extinction
in the direction of the GRB.
We thank the COATLI technical team (Fernando ��ngeles, Oscar Chapa,
Salvador Cuevas, Alejandro Farah, Jorge Fuentes, Rosal��a Langarica,
Fernando Quir��s, and Carlos Tejada) and the staff of the Observatorio
Astron��mico Nacional.
GCN Circular 23484
Subject
GRB 181201A: Global MASTER-Net prompt optical descovery and afterglow observations
Date
2018-12-02T10:26:59Z (7 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa,
A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk
Irkutsk State University
V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk
R. Podesta, Carlos Lopez and F. Podesta
Observatorio Astronomico Felix Aguilar (OAFA)
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias
D. Buckley, S. Potter, A. Kniazev, M. Kotze
South African Astronomical Observatory
MASTER-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru,
Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in
Argentina (OAFA observatory of San Juan National University) was pointed
to the INTEGRAL GRB181201A ((Mereghetti et
al., GCN #23469) 10 sec after notice time and 18 sec
after trigger time at 2018-12-01 02:40:30 UT. We discovered prompt growing (one mag per
minute) optical flash MASTER OT J211711.20-123751.4
(Podesta et al., GCN #23470; Gorbovskoy et al., Atel #12255) at RA,Dec =
21h 17m 11.20s -12d 37m 51.4s
Later we observed afterglow at MASTER-Kislovodsk (Lipunov et al., #23476),
MASTER-SAAO, MASTER-IAC and MASTER-OAFA against in B,V,R,I and Clear fiters.
Observations are continuated.
This message can be cited.
GCN Circular 23485
Subject
GRB 181201A: optical observations in Chilescope observatory
Date
2018-12-02T13:19:51Z (7 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), A. Pozanenko (IKI), E. Mazaeva (IKI), A. Volnova (IKI),
M. Krugov (AFIF) report on behalf of IKI-FuN follow-up collaboration:
We observed the field of the INTEGRAL GRB 181201A (Mereghetti et al.,
GCN 23469) with RC-1000 telescope of CHILESCOPE observatory.
Observations started on Dec. 02 (UT) 01:11:25 in r'-filter. We detected
optical afterglow (e.g. Podesta et al., GCN 23470; Kong, GCN 23475;
Lipunov et al., GCN 23476: Volnova et al., GCN 23477; Heintz et al., GCN
23478; Mazaeva et al., GCN 23479). Preliminary photometry is following.
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2018-12-02 01:11:25 0.9416 r' 300 18.00 0.05
The photometry is based on the SDSS DR12 star
SDSS-DR12_id r
J211710.81-123706.3 16.517
GCN Circular 23486
Subject
GRB 181201A: GROND detection of the afterglow and redshift upper limit of z < 3
Date
2018-12-02T15:19:53Z (7 years ago)
From
Jan Bolmer at MPE/Garching <jan@bolmer.de>
J. Bolmer (MPE, Garching) and P. Schady (Univ. of Bath) report:
We observed the field of GRB 181201A (INTEGRAL trigger; Mereghetti et al., GCN #23469)
simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted
at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).
Observations started at 00:16 UT, 21.85 hrs after the GRB trigger, and were performed
under good seeing conditions, 1.03'', and at an average airmass of 1.43.
We detect a source at a position consistent with the X-ray and optical afterglow
(Page et al., GCN #23474; Podesta et al., GCN #23470; Heintz et al., GCN #23478).
Based on the first 17 min of total exposures in g'r'i'z' and 20 min in JHK, we
measure the following preliminary AB magnitudes:
g' = 18.14 +/- 0.03 mag
r' = 17.97 +/- 0.03 mag
i' = 17.80 +/- 0.03 mag
z' = 17.64 +/- 0.03 mag
J = 17.55 +/- 0.05 mag
H = 17.28 +/- 0.05 mag
K = 17.13 +/- 0.08 mag
Given magnitudes are calibrated against SDSS and 2MASS field stars and
are not corrected for the expected Galactic foreground extinction corresponding
to a reddening of E_(B-V)=0.05 in the direction of the burst (Schlafly &
Finkbeiner 2011).
From a fit to the SED with a simple powerlaw including SMC-like dust
extinction and a model for absoprtion from the Lyman-alpha forest we
determine an upper limit for the redshift of z < 3 and A_V < 0.10 mag.
The powerlaw index is -0.50.
GCN Circular 23488
Subject
GRB 181201A: VLT/FORS2 tentative spectroscopic redshift
Date
2018-12-02T16:53:48Z (7 years ago)
From
Alexander Kann at IAA-CSIC <kann@iaa.es>
L. Izzo, A. de Ugarte Postigo, D. A. Kann (all HETH/IAA-CSIC), D. B.
Malesani (DAWN/NBI/DTU and DARK/NBI), K. E. Heintz (Univ. of Iceland),
N. R. Tanvir (Univ. Leicester), V. D'Elia (SSDC), K. Wiersema (Univ.
Warwick), C. Kouveliotou (GWU), and A. J. Levan (Univ. Warwick) report
on behalf of the Stargate collaboration:
We observed the optical counterpart (Podesta et al., GCN #23470; Kong,
GCN #23475; Lipunov et al., GCN #23476; Volnova et al., GCN #23477;
Heintz et al., GCN #23478; Mazaeva et al., GCN #23479; Watson et al.,
GCN #23481; Belkin et al., GCN #23485; Bolmer & Schady, GCN #23486) of
the long, very bright INTEGRAL GRB 181201A (Mereghetti et al., GCN
#23469) with the ESO VLT UT1 equipped with the FORS2 spectrograph. We
obtained a single 600 s spectrum in the low-resolution grism 300V.
Observations started at 00:50:50 UT on December 2 (i.e., 22.16 hr after
trigger).
In the spectrum, the continuum is detected at excellent signal-to-noise
but is largely featureless. From a non-detection of any break in the
continuum down to 3500 ��, we derive a redshift upper limit of z < 1.88.
There are no strong lines visible, but we note the possible presence of
three weak lines, which, if real, can be identified as the Mg II doublet
and Mg I, implying a redshift of z = 0.450. No emission lines are
visible. Pan-STARRS archive imaging (Chambers et al. 2016,
arXiv:1612.05560) shows the presence of a possible host galaxy at i' ~
23.4 mag.
We acknowledge the ESO observing staff at Paranal, especially Cedric
Ledoux, Joe Anderson, and Rodrigo Tomero. We are also indebted to the
ESPRESSO commissioning team who kindly granted us permission to carry
out this ToO observation during their time.
GCN Circular 23491
Subject
GRB 181201A: Insight-HXMT/HE detection
Date
2018-12-03T01:41:51Z (7 years ago)
From
Ce Cai at IHEP <caice@ihep.ac.cn>
C. Cai, C. K. Li, X. B. Li, G. Li, J. Y. Liao, S. L. Xiong,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, X. F. Lu, J. L. Zhao,
A. M. Zhang, Y. F. Zhang, C. L. Zou (IHEP), Y. J. Jin,
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song,
H. Y. Wang, M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:
At 2018-12-01T02:39:53.000 (T0), the Insight-HXMT/HE detected
GRB 181201A (trigger ID: HEB181201111) in a routine search of the data,
which was also triggered by INTEGRAL (S. Mereghetti et al.,GCN 23469);
Fermi/LAT (M. Arimoto et al., GCN23480).
The Insight-HXMT/HE light curve mainly consists of Single
pulse with a duration (T90) of 15.18 s measured from T0+1.56 s.
The 1-s peak rate, measured from T0+5.28 s, is 13844.5 cnts/s.
The total counts from this burst is 88444.0 counts.
URL_LC: http://www.hxmt.org/images/GRB/HEB181201111_lc.jpg
All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (record energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.
Insight-HXMT is the first Chinese space X-ray telescope, which was
fundedjointly by the China National Space Administration (CNSA) and
the Chinese Academy of Sciences (CAS).
More information could be found at: http://www.hxmt.org.
GCN Circular 23492
Subject
GRB 181201A: Further COATLI Optical Monitoring
Date
2018-12-03T07:12:44Z (7 years ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), William
H. Lee (UNAM), Margarita Pereyra (UNAM), Carlos Rom��n-Z����iga (UNAM),
Alexander Kutyrev (GSFC), and Eleonora Troja (GSFC), report:
We observed the field of GRB 181201A (Mereghetti et al., GCN 23469) with
the COATLI 50-cm telescope and interim imager at the Observatorio
Astron��mico Nacional on the Sierra de San Pedro M��rtir
(http://coatli.astroscu.unam.mx) from 2018-12-03 01:30:45 to 04:14:39
(from 46.9 to 49.6 hours after the trigger), obtaining a total of 1.5
hours of exposure in the w filter.
We continue to detect the optical counterpart reported by Podesta et al.
(GCN Circ. 23470) at w = 18.77 +/- 0.02.
The counterpart has faded by about 1 magnitude since our previous
observations (Watson et al., GCN 23481). Further observations are
planned.
Our w magnitudes are calibrated against the USNO-B1 catalog (adjusted to
an approximate AB system) and are not corrected for Galactic extinction
in the direction of the GRB.
We thank the COATLI technical team (Fernando ��ngeles, Oscar Chapa,
Salvador Cuevas, Alejandro Farah, Jorge Fuentes, Rosal��a Langarica,
Fernando Quir��s, and Carlos Tejada) and the staff of the Observatorio
Astron��mico Nacional.
GCN Circular 23495
Subject
Konus-Wind observation of GRB 181201A
Date
2018-12-03T16:42:48Z (7 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, A. Tsvetkova, A. Lysenko, A. Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 181201A
(INTEGRAL-IBIS/ISGRI detection: Mereghetti et al., GCN Circ. 23469;
Insight-HXMT/HE detection: Cai et al., GCN Circ. 23491)
triggered Konus-Wind at T0=9592.355 s UT (02:39:52.355).
The burst light curve consists of two well-separated pulses
with the first pulse staring at ~T0-115 s,
and a total burst duration of ~172 s.
The emission is seen up to ~15 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB181201_T09592/
As observed by Konus-Wind, the burst
had a fluence of 1.99(-0.06,+0.06)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+4.848 s,
of 2.88(-0.33,+0.34)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+34.816 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.25(-0.05,+0.05),
the high energy photon index beta = -2.73(-0.12,+0.11),
the peak energy Ep = 152(-6,+6) keV
(chi2 = 114/97 dof).
The spectrum near the maximum count rate
(measured from T0+4.352 to T0+4.864 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.75(-0.16,+0.19),
the high energy photon index beta = -2.76(-0.38,+0.21),
the peak energy Ep = 207(-24,+26) keV
(chi2 = 51/49 dof).
Assuming the redshift z=0.450 (Izzo et al., GCN Circ. 23488)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~1.0x10^53 erg,
the peak luminosity L_iso is ~2.2x10^52 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is ~220 keV.
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 23497
Subject
GRB 181201A: continued optical observations in SAAO and Chilesope
Date
2018-12-03T17:38:47Z (7 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), E. Mazaeva (IKI), S. Belkin (IKI), D. Buckley (SAAO),
M. Krugov (AFIF), A. Pozanenko (IKI) report on behalf of IKI-FuN
follow-up collaboration:
We continue multicolor observation the optical afterglow (e.g.
Podesta et al., GCN 23470; Kong GCN 23475) of INTEGRAL GRB 181201A
(Mereghetti et al., GCN 23469) with 1m telescopes of SAAO (SAAO40in)
and Chilescope (RC1000) observatories. Preliminary photometry is
following
Date UT start t-T0 Filter Exp. OT Err. Telescope
(mid, days) (s)
2018-12-02 19:09:26 1.69544 r' 2*600 18.69 0.02 SAAO40in
2018-12-02 19:30:07 1.70980 i' 2*600 18.54 0.07 SAAO40in
2018-12-02 19:50:44 1.72759 g' 3*600 19.07 0.05 SAAO40in
2018-12-03 01:32:26 1.95794 r' 600 18.92 0.04 RC1000
The photometry is based on the SDSS DR12 star
SDSS-DR12_id g r i
J211710.81-123706.3 17.191 16.517 16.257
GCN Circular 23499
Subject
GRB 181201A: Swift/UVOT Detection
Date
2018-12-04T00:22:12Z (7 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and J. K. Cannizzo (NASA/UMBC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 18201A
14.3 ks after the INTEGRAL trigger (Mereghetti et al., GCN Circ. 23469).
We confirm the optical afterglow initially reported by MASTER (Podeta et al.,
GCN Circ. 23470, Kong, GCN Circ. 23475, Volnova et al., GCN Circ. 23477, Mazaeva
et al., GCN Circ. 23479, Watson et al., GCN Circ. 23481, Belkin et al., GCN Circ.
23485, Bolmer and Schady, GCN Circ. 23486, Cai et al., GCN Circ. 23491). The
position of the afterglow is also consistent with the XRT afterglow
(Page et al., GCN Circ. 23474). The detection of the afterglow in the uvw2
filter would be consistent with the redshift report by Izzy et al. (GCN Circ. 23488).
The preliminary UVOT position is:
RA (J2000) = 21:17:11.17 = 319.29656 (deg.)
Dec (J2000) = -12:37:51.0 = -12.63084 (deg.)
with an estimated uncertainty of 0.2 arc sec. (radius, 90% confidence).
Preliminary detections 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
uvw2 14310 26435 4901 15.39 +/- 0.02
white 56416 74104 924 17.53 +/- 0.03
white 148341 165117 1162 18.71 +/- 0.04
v 56713 74204 535 17.70 +/- 0.10
v 160066 165389 389 18.70 +/- 0.26
u 56120 77881 2757 17.25 +/- 0.03
u 148114 164276 2896 18.30 +/- 0.05
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 23501
Subject
GRB 181201A: AstroSat CZTI detection
Date
2018-12-04T05:29:05Z (7 years ago)
From
Vidushi Sharma at IUCAA <vidushi@iucaa.in>
T. Khanam, V. Sharma and A. Vibhute (IUCAA), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data showed the detection of a long GRB 181201A, which was also detected by Integral-IBIS/ISGRI detection (Mereghetti S. et al., GCN 23469), Insight-HXMT/HE detection (Cai C. et al., GCN 23491) and Konus-Wind (Svinkin D. et al., GCN 23495).
The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 02:39:58.020 UT, ~2 min after the Integral-IBAS trigger. The measured peak count rate is 910.8 cts/s above the background in combined data of four quadrants, with a total of 6099 cts. The local mean background count rate was 569 cts/s. Using cumulative rates, we measure a T90 of 19.2 s. In preliminary analysis, we find that 402 compton events are associated with this event.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.
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 23503
Subject
GRB181201A: GOTO optical observations
Date
2018-12-04T14:09:38Z (7 years ago)
From
Danny Steeghs at U.of Warwick/GOTO <dsteeghs@gmail.com>
G.Ramsay (Armagh O.), J.Lyman, K.Ulaczyk, D.Steeghs, K.Wiersema
(U. Warwick), M.Dyer (U. Sheffield), B.Gompertz, A.Levan, R.Cutter
(U. Warwick) K. Ackley, D.Galloway, E.Rol (Monash U.), V.Dhillon
(U. Sheffield), P.O'Brien, R.Starling (U. Leicester), S.Poshyachinda
(NARIT), D.Pollacco (U. Warwick), E.Thrane (Monash U.), E.Palle (IAC)
report on behalf of the GOTO collaboration:
The Gravitational-wave Optical Transient Observer observed the field
of the long duration GRB 181201A (Mereghetti et al. GCN Circ. 23469,
Page et al. GCN Circ. 23474) from Roque de los Muchachos Observatory.
We report two optical photometric detections, both made using a
combined L-band image (400-700nm passband), each with a total exposure
time of 300s. The resulting preliminary magnitudes are based on a
comparison to Panstarrs g-band calibrators and include a systematic
error component due to the calibration uncertainty.
midpoint time elapsed since burst g
2018-12-01 19:33:18 UT 0.705 days 17.74+/-0.10 mag
2018-12-03 19:41:21 UT 2.711 days 19.48+/-0.15 mag
GOTO is operated at the La Palma observing facilities of the
University of Warwick on behalf of a consortium including the
University of Warwick, Monash University, Armagh Observatory, the
University of Leicester, the University of Sheffield, the National
Astronomical Research Institute of Thailand (NARIT) and the Instituto
de Astrofisica de Canarias (IAC) (https://goto-observatory.org/)
GCN Circular 23504
Subject
GRB 181201A: Continued GROND observations show that afterglow is still bright
Date
2018-12-04T15:06:49Z (7 years ago)
From
Jan Bolmer at MPE/Garching <jan@bolmer.de>
J. Bolmer (MPE, Garching) and P. Schady (Univ. of Bath) report:
We observed again the field of GRB 181201A (INTEGRAL trigger; Mereghetti et al., GCN #23469)
simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted
at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).
Observations started at 01:01 UT on 4. of Dezember 2018, about three days after the
GRB trigger, and were performed under poor seeing conditions, 2.2'', and at an average
airmass of 2.0.
We still detect the afterglow and based on 17 min of total exposure time,
we measure the following preliminary r'-band AB magnitude, indicating
that the afterglow is still reltively bright, even three days after the
detection of the prompt emission:
r' = 19.43 +/- 0.03 mag
Given magnitude is calibrated against SDSS and not corrected for the
expected Galactic foreground extinction corresponding to a reddening of
E_(B-V)=0.05 in the direction of the burst (Schlafly & Finkbeiner 2011).
GCN Circular 23507
Subject
GRB 181201A: continued optical observations in TSHAO
Date
2018-12-04T18:59:33Z (7 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
I. Reva (AFIF), M. Krugov (AFIF), A. Volnova (IKI), E. Mazaeva (IKI), S.
Belkin (IKI), A. Pozanenko (IKI) report on behalf of IKI-FuN follow-up
collaboration:
We continue observations the optical afterglow (e.g. Podesta et al.,
GCN 23470; Kong GCN 23475) of INTEGRAL GRB 181201A (Mereghetti et
al., GCN 23469) with Zeiss-1000 1-m telescope of Tien Shan
Astronomical Observatory. Preliminary photometry of the afterglow in
R-filter on December 04 is following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2018-12-04 12:19:26 3.4202 R 2400 19.67 0.07
The photometry is based on the SDSS-DR12 star
SDSS-DR12_id R(Lupton)
J211710.81-123706.3 16.296
GCN Circular 23510
Subject
GRB181201A: Optical afterglow measurements by GROWTH-India
Date
2018-12-05T05:07:03Z (7 years ago)
From
Varun Bhalerao at Indian Inst of Tech <varunb@iitb.ac.in>
Shubham Srivastava (IITB), Harsh Kumar (IITB), Stanzin Otzer (IIA), Kishalay De (Caltech), Varun Bhalerao (IITB), G C Anupama (IIA) and Mansi Kasliwal (Caltech) report on behalf of the GROWTH collaboration:
The long duration GRB181201A (Mereghetti et al., GCN 23469, Sharma et al., 23501) was observed by the GROWTH-India telescope in the g-band for an integration time of 600s. The afterglow was clearly detected, and the magnitude was calibrated using field stars from the PS1 catalog.
t_mid delta_t mag mag_err
2018-12-04 13:27:45 UT 3.4512 19.97 0.13
The GROWTH India telescope is a 70-cm telescope with a 0.7 degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).
The data were obtained as part of the GROWTH Winter School at IIT Bombay with 70 participants - http://growth.caltech.edu/growth-winter-school-2018.html
GCN Circular 23514
Subject
GRB 181201A: continued optical observations in TSHAO and Chilesope
Date
2018-12-05T20:49:30Z (7 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), I. Reva (FAI), A. Pozanenko (IKI), A. Volnova (IKI),
E. Mazaeva (IKI), A. Kusakin (FAI), M. Krugov (FAI), D. Buckley (SAAO)
report on behalf of IKI-FuN follow-up collaboration:
We continue multicolor observations the optical afterglow (e.g.
Podesta et al., GCN 23470; Kong GCN 23475) of INTEGRAL GRB 181201A
(Mereghetti et al., GCN 23469) with 1m telescopes of TSHAO
(Zeiss-1000) and Chilescope (RC1000) observatories. Preliminary
photometry is following
Date UT start t-T0 Filter Exp. OT Err. Telescope
(mid, days) (s)
2018-12-05 01:04:38 3.92822 r' 1200 19.74 0.05 RC-1000
2018-12-05 12:17:22 4.42306 R 2280 19.82 0.07 Zeiss-1000/TSHAO
The photometry is based on the SDSS-DR12 star
SDSS-DR12_id g r i R(Lupton)
J211710.81-123706.3 17.191 16.517 16.257 16.296
GCN Circular 23518
Subject
GRB 181201A: ALMA detection of a fading mm afterglow
Date
2018-12-07T17:08:24Z (7 years ago)
From
Tanmoy Laskar at UC Berkeley <tanmoylaskar@gmail.com>
T. Laskar (University of Bath), E. Berger (Harvard), R. Chornock (Ohio
University), W. Fong (Northwestern), R. Margutti (Northwestern), C. G.
Mundell (University of Bath), and P. Schady (University of Bath) report on
behalf of a larger collaboration:
"We observed GRB 181201A (Mereghetti et al. GCN 23469) with the Atacama
Large Millimeter/Submillimeter Array (ALMA) starting at 0.9 d after the
burst at 90 GHz. Preliminary analysis reveals a bright (S/N > 150), fading
mm counterpart at a location consistent with the X-ray position (Page et
al. GCN 23474) and optical position (Podesta et al., GCN 23470; Lipunov et
al., GCN 23476, GCN 23484; Siegel & Cannizzo, GCN 23499). Follow-up
observations are planned.
We thank the JAO staff, AoD, and the ALMA team for their help with these
observations."
GCN Circular 23519
Subject
GRB 181201A: VLA detection
Date
2018-12-07T18:52:33Z (7 years ago)
From
Tanmoy Laskar at UC Berkeley <tanmoylaskar@gmail.com>
T. Laskar (University of Bath), E. Berger (Harvard), R. Chornock (Ohio
University), W. Fong (Northwestern), R. Margutti (Northwestern), C. G.
Mundell (University of Bath), and P. Schady (University of Bath) report on
behalf of a larger collaboration:
"We observed GRB 181201A (Mereghetti et al. GCN 23469) with the Karl G.
Jansky Very Large Array (VLA) beginning on 2018 December 04.02 UT (2.9 d
after the burst). At a mean frequency of 6.0 GHz, we detect a radio source
at the position
RA (J2000) = 21:17:11.185 +/- 0.001
Dec (J2000) = -12:37:51.37 +/- 0.03
consistent with the position of the optical afterglow (Podesta et al., GCN
23470; Lipunov et al., GCN 23476, GCN 23484; Siegel & Cannizzo, GCN 23499)
and the XRT afterglow (Page et al. GCN 23474). Follow-up observations are
planned.
We thank the VLA staff for rapidly executing these observations."
GCN Circular 23522
Subject
GRB 181201A: continued optical observations in Mondy
Date
2018-12-09T20:12:31Z (7 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), E. Klunko (ISTP), S. Belkin (IKI), A. Volnova (IKI),
A. Pozanenko (IKI) report on behalf of of larger GRB follow-up
collaboration:
We continue observations the optical afterglow (e.g. Podesta et al.,
GCN 23470; Kong GCN 23475) of INTEGRAL GRB 181201A (Mereghetti et
al., GCN 23469) with AZT-33IK telescope of Sayan observatory
(Mondy). Preliminary photometry of the OT is following.
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2018-12-03 11:24:39 2.38658 R 30*120 18.91 0.03
2018-12-05 11:26:24 4.38780 R 30*120 20.03 0.09
2018-12-07 10:57:13 6.36753 R 30*120 20.23 0.05
The photometry is based on the SDSS-DR12 star
SDSS-DR12_id R(Lupton)
J211710.81-123706.3 16.3
GCN Circular 23601
Subject
GRB 181201A: photometric signature of the SN
Date
2019-01-03T20:40:28Z (6 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), E. Mazaeva (IKI), A. Pozanenko (IKI), P. Minaev
(IKI), A. Volnova (IKI), N. Tominaga (Konan University), S. Blinnikov
(ITEP), D. Chestnov (KIAM), E. Klunko (ISTP), I. Reva (FAPI), V.
Rumyantsev (CrAO), D. Buckley (SAAO), R. Ya. Inasaridze (AbAO) report
on behalf of GRB-FuN collaboration:
We observed the optical afterglow (e.g. Podesta et al., GCN 23470;
Kong GCN 23475) of the INTEGRAL GRB 181201A (Mereghetti et al., GCN
23469) with Gemini-N telescope on Dec. 22 in g'r'i'z and Dec. 24 in
r'i'-filters. Preliminary photometry of the OT is following.
Date t-T0 Filter Exp. OT Err.
(mid, days) (s)
2018-12-22 21.10536 i' 3*180 21.50 0.03
2018-12-22 21.09536 r' 3*180 21.82 0.03
2018-12-24 23.09418 i' 3*180 21.32 0.06
2018-12-24 23.10793 r' 3*240 21.83 0.03
The photometry is based on the SDSS-DR12 star
SDSS-DR12_id i' r'
J211710.81-123706.3 16.257 16.517
Based on our previous observations and photometry reported in GCNs
23475, 23478, 23486, 23504 we plot a light curve of the afterglow in
r'-filter (http://grb.rssi.ru/GRB181201A/GRB181201A_optics_fit.png).
Power law approximation of the LC before 2018-12-22 has an index of
1.19 +/-0.01. The photometry obtained on 2018-12-22 and 2018-12-24 has a
significance of about 2 and 6.5 sigma above the power law approximation.
Additionally the i'-magnitude increases between the two epochs. We can
suggest that we observed the Supernova signature associated with GRB
181201A.