- GCN Circular #28831
A. Ursi (INAF/IAPS), C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), M.
Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C.
Casentini, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and
INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ.
Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of
the AGILE Team:
The AGILE satellite detected a burst at T0 = 2020-11-03 18:06:45.36 +/-
0.01 s (UTC), reported by INTEGRAL/SPI-ACS (trigger ID 8788,0).
The burst is clearly visible in the AGILE scientific ratemeters of the
SuperAGILE (SA; 20-60 keV), MiniCALorimeter (MCAL; 0.4-100 MeV), and
AntiCoincidence (AC; 50-200 keV) detectors. The event lasted ~7 s and
released a total number of 1850 counts in the SA detector (above a
background rate of 90 Hz), 25200 counts in the MCAL detector (above a
background rate of 1260 Hz), and 73000 counts in the AC detector (above a
background rate of 3650 Hz). The AGILE ratemeter light curves can be found
at http://www.agilescienceapp.it/notices/GRB_201103B_AGILE_RM.png .
The event also triggered a partial high time resolution MCAL data
acquisition.
Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert
Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.
- GCN Circular #28841
Michael Coughlin (UMN), Igor Andreoni (Caltech), Shreya Anand (Caltech),
Erik Kool (OKC), Ana Sagues Carracedo (OKC), Anna Ho (UCB), Mansi Kasliwal
(Caltech), Daniel Perley (LJMU) on behalf of the Zwicky Transient Facility
(ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH)
collaborations
We report the discovery of the fast optical transient ZTF20acozryr/AT2020yxz
with the Zwicky Transient Facility (ZTF, Bellm et al. 2019, Graham et al.
2019) at coordinates (J2000, <0.5”):
RA = 02:48:44.31 (42.1846d)
Dec = +12:08:14.08 (+12.1372d)
ZTF20acozryr was found by the new “ZTF Realtime Search and Triggering”
(ZTF-ReST) project, which aims at near real-time identification of
compelling kilonova candidates in ZTF data using the methods described in
Andreoni et al. (2020d), independently of gravitational-wave or gamma-ray
triggers.
ZTF20acozryr was first detected on 2020-11-03 09:44 UT, hereafter labelled
T_det. It faded by ~0.7 mag in g-band in the first 0.9 days since T_det.
The transient was last detected on 2020-11-05 08:13:20 UT at r = 19.9 ± 0.2
mag. Stringent upper limits constrain the transient onset time to be within
~1 day from T_det. The color of the transient appears to be red, with
g-r~0.3 at T_det. The Galactic extinction on the line of sight is low, with
E(B-V)=0.10 mag (Planck Collaboration et al., 2015).
In the table below, we report photometry obtained on images processed in
real-time through the ZTF reduction and image subtraction pipelines at IPAC
(Masci et al. 2019).
-----------------±-------±-----±-----
Date (UT) | mag | emag | band
-----------------±-------±-----±-----
2020-11-03 09:44 | > 19.4 | - | g
2020-11-04 08:47 | 19.5 | 0.2 | g
2020-11-04 10:28 | 19.2 | 0.1 | r
2020-11-05 06:43 | 20.2 | 0.3 | g
2020-11-05 08:13 | 19.9 | 0.2 | r
-----------------±-------±-----±-----
ZTF20acozryr is located off the Galactic plane, with Galactic latitude
b_Gal = -41.5 deg. Deep Legacy Survey and Pan-STARRS1 images of the field
do not reveal any permanent source at the transient location. There are two
nearby sources reported in the Legacy Survey DR8 catalog. The first source
(RA, Dec = 42.1845d, 12.1358d) has a separation of 5.24 arcsec (with a
galaxy classification from DR8) from ZTF20acozryr and has reported
magnitudes of g=24.38 mag, r=23.45 mag, and z=23.04 mag. The second source
(RA, Dec = 42.1861d, 12.1395d) has a separation of 9.60 arcsec from
ZTF20acozryr (with a point source classification from DR8) and has reported
magnitudes of g=24.84 mag, r=24.07 mag, and z=23.49 mag.
There do not appear to be any publicly reported GRBs consistent with the
sky location between the last non-detection and the first detection.
We encourage spectroscopic classification and multi-wavelength follow-up to
discern the nature of ZTF20acozryr, a potential orphan afterglow candidate.
ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC,
USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY,
Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan;
IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia.
ZTF acknowledges the generous support of the NSF under AST MSIP Grant No
1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant
No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et
al. 2019). Alert database searches are done with Kowalski (Duev et al.
2019).
- GCN Circular #28844
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,
K. Hurley, on behalf of the IPN,
I. G. Mitrofanov, D. V. Golovin, A. S. Kozyrev, M. L. Litvak,
and A. B. Sanin, on behalf of the HEND-Odyssey GRB team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
S. Barthelmy, J. Cummings, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT team,
A. Ursi, N. Parmiggiani, F. Verrecchia, A. Bulgarelli,
A. Trois, M. Marisaldi, C. Pittori, M. Tavani, Y. Evangelista,
I. Donnarumma, M. Cardillo, G. Piano, G. Minervini, A. Argan,
F. Lucarelli, A. Zoli, V. Fioretti, F. Fuschino, M. Pilia,
F. Longo, A. Giuliani on behalf of the AGILE team,
and
W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:
The long-duration, bright GRB 201103B
(AGILE detection: Ursi et al., GCN Circ. 28831)
has been detected by AGILE, Konus-Wind, INTEGRAL (SPI-ACS),
Mars-Odyssey (HEND), and Swift (BAT),
so far, at about 65207 s UT (18:06:47).
The burst was outside the coded field of view of the BAT.
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
42.089 (02h 48m 21s) +12.441 (+12d 26' 29")
Corners:
41.830 (02h 47m 19s) +14.128 (+14d 07' 41")
42.595 (02h 50m 23s) +11.069 (+11d 04' 07")
42.244 (02h 48m 59s) +10.759 (+10d 45' 32")
41.511 (02h 46m 03s) +13.781 (+13d 46' 52")
---------------------------------------------
The error box area is 1.24 sq. deg, and its maximum
dimension is 3.4 deg (the minimum one is 23.8 arcmin).
The Sun distance was 175 deg.
This box may be improved.
The distance between the optical transient ZTF20acozryr/AT2020yxz (Coughlin
et al., GCN Circ. 28841) and the IPN box center is 19 arcmin, thus
confirming the association of the burst and the OT.
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB201103_T65207/IPN
The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.
- GCN Circular #28846
D. Xu (NAOC), Z.P. Zhu (NAOC, HUST), S.Y. Fu, X. Liu (NAOC), X. Gao
(Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the optical transient, ZTF20acozryr/AT2020yxz, an likely
orphan GRB optical afterglow when discovered by ZTF (Coughlin et al.,
GCN 28841) and later confirmed by the IPN localisation as the optical
afterglow of GRB 201103B (Svinkin et al., GCN 28844), using the
NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China.
Observations started at 17:33:06 UT on 2020-11-05 and a series of 120s
exposures were obtained in the Sloan r-filter.
Considering the IPN trigger time, 18:06:47 UT on 2020-11-03, as the
onset of the burst, preliminary photometry results are as follows:
T_mid_obs (UT) T_mid_grb(day) Mag MagErr
2020-11-05T17:43:35 1.984 20.5 0.3
2020-11-05T18:31:28 2.017 20.8 0.2
calibrated with nearby PS1 stars.
Compared with the ZTF photometry, such a decay is consistent with that
of a conventional GRB optical afterglow.
- GCN Circular #28847
D. Xu (NAOC), J.-B. Vielfaure (APC, Paris University), D. A. Kann
(HETH/IAA-CSIC), D. B. Malesani (DTU Space), D. A. Perley (LJMU), A. J.
Levan (Radboud U. Nijmegen), S. Klose (TLS Tautenburg), K. Wiersema
(Univ. Warwick), and A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI)
report on behalf of the Stargate Consortium:
We observed the transient ZTF20acozryr/AT2020yxz (Coughlin et al., GCN
28841), which has been proposed to be the optical afterglow of GRB
201103B (Svinkin et al., GCN 28844) using the ESO VLT UT3 (Melipal)
equipped with the X-shooter spectrograph. Our spectra cover the
wavelength range 3000-21000 AA, and consist of 4 exposures of 1200 s
each. The observation mid-time was 2020 Nov 6.116 UT (56.66 hr/2.361
days after the GRB).
In a 60 s image taken with the acquisition camera on Nov 6.0771 UT, we
detect the optical afterglow, for which we measure a preliminary
magnitude r ~ 20.7 mag (AB magnitude, calibrated against a nearby galaxy
from the Pan-STARRS catalog; Chambers et al. 2016, arXiv:1612.05560).
We clearly detect continuum over the entire wavelength range. From
detection of multiple absorption features, which we interpret as due to
CII, MgII, and multiple FeII lines, we infer a redshift z = 1.105. We
suggest this to be the redshift of the transient, which we hereby
confirm spectroscopically to be the afterglow of GRB 201103B.
We acknowledge excellent support from the ESO observing staff in Paranal.
- GCN Circular #28848
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the ZTF GRB 201104C.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021039
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 ZTF 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 #28849
P.A. Evans reports on behalf of the Swift-XRT team:
GCN CIrcular 28848 incorrectly referred to GRB 201104C. This was due to a software error, not recognising
'ZTF20acozryr�?? as a GRB name.
Swift is actually carrying out observations of the source ZTF20acozryr (Coughlin et al., GCN Circ. 28841) which
has been possibly associated with GRB 201103B (Svinkin et al., GCN Circl. 28844), and has a redshift of 1.105
(Xu et al., GCN Circl. 28847).
The results of the automated search for an X-ray counterpart consistent with the ZTF position, and analysis of
any source(s) found, will appear at the URL previous circulated, i.e.
https://www.swift.ac.uk/ToO_GRBs/00021039
Although the nature of this object has not been confirmed, the zeropoint for any source light curves will be
set to the IPN trigger time, in the first instance.
We apologise for the confusion.
- GCN Circular #28854
Z.P. Zhu (NAOC, HUST), S.Y. Fu, X. Liu, L.P. Xin, J.Y. Wei, D. Xu (NAOC)
report on behalf of a larger collaboration:
We observed the field of ZTF20acozryr/AT2020yxz (Coughlin et al. GCN
28841), likely the optical afterglow of GRB 201103B (Svinkin et al., GCN
28844), using the 2.16m telescope equipped with the BFOSC camera at
Xinglong, Hebei, China. Observations started at 14:12:36 UT on
2020-11-06, and 8x180s R-band frames were obtained.
The source is clearly detected in our stacked image, with R = 20.36 +/-
0.05 mag at Tmid-T0 = 2.8373 days post-burst, calibrated with nearby
Pan-STARRS1.
We acknowledge excellent support from the Xinglong-2.16m observing
staff, in particular Jie Zheng.
- GCN Circular #28858
P. A. Evans (U Leicester), N. P. M. Kuin (UCL-MSSL) and B. Sbarufatti (PSU) report on behalf of the Swift team:
Swift-XRT has performed follow-up observations of the ZTF-detected afterglow candidate ZTF20acozryr/AT2020yxz, (Coughlin et al., GCN 28841) proposed to be associated with the AGILE and IPN-detected GRB 201103B (Ursi et al., GCN Circ. 28831, Svinkin et al., GCN Circ. 28844), collecting 1.2 ks of Photon Counting (PC) mode data between T0+199.5 ks and T0+206.0 ks.
An uncatalogued X-ray source is detected, at RA, Dec=42.1842, +12.1382 which is equivalent to:
RA (J2000): 02:48:44.21
Dec(J2000): +12:08:17.6
with an uncertainty of 5.3 arcsec (radius, 90% confidence). This position is 3.8 arcsec from the ZTF position, consistent with that source. We cannot determine at the present time whether the source is fading.
The mean count-rate of the source is (1.5 +/- 0.5) x 10^-3 ct/sec, and we cannot yet confirm any variability.
This location has been previously observed by Swift in 2014 November, and these observations are in the 2SXPS catalogue (Evans et al., 2020):
https://www.swift.ac.uk/2SXPS/doSimpleSearch.php?searchpos=42.18421+12.1382&searchrad=750&getWhat=1&subset=1&dssubset=0&coordType=0&retType=0&searchWhat=1
The stacked image (field 10000005379) created from the 2014 observation contained about 2043 s of exposure at this position, and contained only 2 events at the ZTF location, giving a 3-sigma upper limit of 5.4 x 10^-3 ct/sec. Thus the XRT source reported above is a transient event, and we identify it as the X-ray afterglow to GRB 201103B.
It has been pointed out to us that we incorrectly stated in GCN 28849 that the nature of the object had not been confirmed, whereas Xu et al (GCN Circ. 28847) has in fact confirmed the associated with the GRB via their spectroscopy. We apologize for the confusion.
The automated analysis of this object is available at https://www.swift.ac.uk/xrt_products/00021039
A source is also detected in UVOT data with magnitude B=20.25+-0.26 at ~T+205 ks. A weak signal is also detected in the V band at less than 3 sigma significance (V > 19.6) with some evidence of fading.
This circular is an official product of the Swift XRT and UVOT teams.
- GCN Circular #28861
J. Mao, C.-J. Wang, and J.-M. Bai (YNAO) report:
We observed the field of GRB201103B/ZTF20acozryr/AT2020yxz with the 2.4-meter optical telescope
at Gao-Mei-Gu (GMG) station of Yunnan Observatories. The observation began at UT 16:41:52, 6th,
Nov. 2020. We clearly detected the source, and the preliminary magnitude is measured to be R~20.6.
- GCN Circular #28862
S. Belkin (IKI), M. Krugov (FAI), V. Kim (FAI, Pulkovo Observatory), A.
Pozanenko (IKI), N. Pankov (HSE) report on behalf of GRB-IKI-FuN:
We observed the ZTF20acozryr/AT2020yxz (Coughlin et al., GCN 28841)
with AZT-20 telescope of Assy-Turgen observatory starting on Nov. 06
(UT) 19:10:28 in r'-filter. We detect the optical transient (Coughlin
et al., GCN 28841; Coughlin et al., GCN 28841; Xu et al., GCN 28846;
Xu et al., GCN 28854; Mao et al., GCN 28861; ) which can be afterglow
of GRB 201103B (Svinkin et al., GCN 28844; Evans et al., GCN 28858).
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err. UL (3sigma)
(mid, days) (s)
2020-11-06 19:10:28 3.06508 r'(AB) 60*60 20.84 0.06 23.1
The photometry is based on the nearby stars of PanSTARRS-PS1.
RA DEC r
02:48:57.72094 +12:12:04.2202 16.6938
02:48:41.68064 +12:09:59.6523 17.0772
- GCN Circular #28863
J. Mao, C.-J. Wang, and J.-M. Bai (YNAO) report:
We observed the field of GRB201103B/ZTF20acozryr/AT2020yxz with
the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan
Observatories once again. The observation began at UT 14:27:51, 7th,
Nov. 2020. We clearly detected the source, and the preliminary magnitude
is measured to be R~20.9. It seems that the source is fading very slightly.
We suggest to perform both photometric monitors to obtain the variability
behavior and spectral observations to obtain the possible spectral evolution
in the following nights.
- GCN Circular #28872
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 201103B
(AGILE detection: Ursi et al., GCN Circ. 28831;
ZTF afterglow discovery: Coughlin et al., GCN Circ. 28841;
IPN triangulation: Svinkin et al., GCN Circ. 28844)
triggered Konus-Wind at T0=65207.923 s UT (18:06:47.923).
The burst light curve shows a multi-peaked structure
which starts at ~T0-14 s, peaks at ~T0+1.5, and ends at ~T0+20 s,
followed by a weaker emission seen up to ~T0+91 s.
The total burst duration is ~105 s.
The emission is seen up to ~5 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB201103_T65207/
As observed by Konus-Wind, the burst
had a fluence of 5.26(-0.77,+0.82)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.536 s,
of 1.49(-0.24,+0.25)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+16.640 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.72(-0.16,+0.19),
the high energy photon index beta = -2.54(-1.13,+0.33),
the peak energy Ep = 403(-60,+74) keV
(chi2 = 102/97 dof).
The spectrum near the maximum count rate
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.71(-0.12,+0.13)
and Ep = 466(-47,+58) keV (chi2 = 104/98 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.4
(chi2 = 102/97 dof).
Assuming the redshift z=1.105 (Xu et al., GCN Circ. 28847)
and a standard cosmology model with H_0 = 67.3 km/s/Mpc,
Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~1.8x10^53 erg,
the peak luminosity L_iso is ~1.1x10^53 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,z,i is ~850 keV.
With these values, GRB 201103B is consistent with the 'Amati'
and 'Yonetoku' relations built for 316 KW GRBs with known z
classified as Type II (Tsvetkova et al., ApJ 2020 submitted).
The 68% and 90% prediction bands for Type II are show with
dark and light shaded regions, respectively, see
http://www.ioffe.ru/LEA/GRBs/GRB201103_T65207/GRB201103B.pdf
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
- GCN Circular #28875
S. Belkin (IKI), E. Klunko (ISTP), A. Zhornichenko (KIAM), A. Kusakin
(FAI), I. Reva(FAI), A. Pozanenko (IKI), N. Pankov (HSE) report on
behalf of GRB IKI FuN:
We observed the ZTF20acozryr/AT2020yxz (Coughlin et al., GCN 28841)
with AZT-33IK telescope of Mondy observatory, RC-36 telescope of Kitab
observatory, and Zeiss-1000 of Tian Shan observatory. We detect the
optical transient (Coughlin et al., GCN 28841; Xu et al., GCN 28846;
Zhu et al., GCN 28854; Mao et al., GCN 28861; Belkin et al., GCN 28862;
Mao et al., GCN 28863) associated with afterglow of GRB 201103B (Ursi
et al., GCN 28831; Svinkin et al., GCN 28844; Evans et al., GCN 28858).
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err. UL. Telescope
(mid, days) (s)
2020-11-05 21:57:40 2.16938 CR 26*60 n/d n/d 19.0 RC-36
2020-11-06 15:42:41 2.92217 R 32*120 20.23 0.26 20.5 AZT-33IK
2020-11-06 16:56:13 2.97237 R 32*120 20.49 0.12 21.7 Z-1000
2020-11-08 14:13:52 4.85911 R 32*120 21.50 0.10 23.0 AZT-33IK
The photometry is based on the nearby stars of PanSTARRS-PS1
RA DEC r
02:48:57.72094 +12:12:04.2202 16.6938
02:48:41.68064 +12:09:59.6523 17.0772
- GCN Circular #28876
K. Sharma (IITB), H. Kumar (IITB), P. Dorjay (IAO), J. Stanzin (IAO), U.
Stanzin (IAO), V. Bhalerao (IITB), G. C. Anupama (IIA), S. Barway (IIA),
report on behalf of the GROWTH-India collaboration:
We followed-up the optical afterglow ZTF20acozryr (Michael Coughlin et.
al., GCN #28841) of GRB 201103B, detected by the AGILE (GCN #28831) and IPN
(D. Svinkin et. al. GCN #28844), with 0.7 m GROWTH-India telescope. We
obtained 300-sec exposures in the SDSS r' filter over multiple nights.
Here are the photometric results from GIT observations:-
--------------------------------------------------
JD (mid) | Filter | Exposure | mag | e_mag |
--------------------------------------------------
2459160.322200 | r' | 300 x 20 | 21.08 | 0.08 |
2459163.145455 | r' | 300 x 30 | 21.91 | 0.06 |
--------------------------------------------------
Combining our photometric results with r/r' band measurements of Michael
Coughlin et. al., GCN #28841; D. Xu et. al., GCN #28846; D. Xu et. al., GCN
#28847; S. Belkin et. al., GCN #28862; we conclude that the source is
fading with a power-law index of 1.16 +/- 0.07. The magnitudes are
calibrated against PanSTARRs PS1 data release, (Flewelling et al., 2018)
and are not corrected for galactic extinction.
The GROWTH India Telescope (GIT) 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).
- GCN Circular #28880
Gregory S.H. Paek (SNU), Myungshin Im (SNU), Joonho Kim (SNU), Gu Lim
(SNU), Mankeun Jeong (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI),
Hyun-Il Sung (KASI), Taewoo Kim (DOAO), and Wonseok Kang (DOAO) and GECKO
team
We observed the ZTF20acozryr/AT2020yxz (Coughlin et al., GCN 28841) in
BVRI with various optical telescopes of the GW EM-Counterpart Korean
Observatory (GECKO). The facilities used for the observations are the 1.6-m
class telescopes of Korea Microlensing Telescope Network (KMTNet) located
in Siding Spring Observatory (SSO) and South African Astronomical
Observatory (SAAO), the 1-m telescope in Deokheung Optical Astronomy
Observatory (DOAO), the 1-m telescope the Mt. Lemmon Optical Astronomy
Observatory (LOAO), and the 0.36-m KIAS Chamnun Telescope (KCT) and RASA36
telescope in Chile. We calibrated flux with PS1 and APASS catalog, and the
magnitudes are in AB system. The magnitudes are not corrected for galactic
extinction. Preliminary R-band magnitudes are given for the most recent a
few epoch observations.
Obs.&Tel. DATE-OBS(UT) Filter Mag Error t-t0(days since
burst)
----------- ----------------------- ------ ------- -----------------------------
DOAO 2020-11-08T19:51:31 R 21.6 0.1 5.07
KCT 2020-11-10T04:27:38 R 21.8 0.3 6.43
KMTNet-SAAO 2020-11-10T21:37:55 R 21.8 0.1 7.1
t0 = 2020-11-03T18:06:45.36 (Ursi et al., GCN 28831)
About a week after GRB occurs, the brightness seems to remain nearly
constant, suggesting a possible onset of a supernova component accompanied
with GRB.
We thank all the operators at GECKO facilities for performing the
observation.
Gravitational-wave EM Counterpart Korean Observatory (GECKO) is a network
of 10+ 0.5m to 1m class telescopes over the world.
- GCN Circular #28883
S. Belkin (IKI), N. Pankov (HSE), A. Pozanenko (IKI), E. Klunko (ISTP),
report on behalf of GRB IKI FuN:
We continued observations of the ZTF20acozryr/AT2020yxz (Coughlin et
al., GCN 28841) with AZT-33IK telescope of Mondy observatory. We
detect the optical transient (Coughlin et al., GCN 28841; Xu et al.,
GCN 28846; Zhu et al., GCN 28854; Mao et al., GCN 28861; Belkin et al.,
GCNs 28862, 28875; Mao et al., GCN 28863; Kumar et al., GCN 28876;
SungHak et al., GCN 28880) at redshift z = 1.105 (Xu et al., GCN
28847) associated with afterglow of GRB 201103B (Ursi et al., GCN 28831;
Svinkin et al., GCN 28844; Evans et al., GCN 28858).
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err. UL. Telescope
(mid, days) (s)
2020-11-09 14:53:25 5.88657 R 30*120 21.67 0.19 22.5 AZT-33IK
2020-11-11 13:59:54 7.84871 R 29*120 21.60 0.25 21.8 AZT-33IK
The photometry is based on the same stars used in GCNs 28862, 28875.
- GCN Circular #28886
S. Belkin (IKI), A. Pozanenko (IKI), V. Rumyantsev (CrAO), N. Pankov
(HSE) report on behalf of GRB IKI FuN:
We continued observations of the ZTF20acozryr/AT2020yxz (Coughlin et
al., GCN 28841) with ZTSh 2.6m telescope of CrAO observatory starting
on Nov., 13 (UT) 22:58:04. We detect the optical transient (Coughlin et
al., GCN 28841; Xu et al., GCN 28846; Zhu et al., GCN 28854; Mao et
al., GCN 28861; Belkin et al., GCNs 28862, 28875, 28883; Mao et al.,
GCN 28863; Kumar et al., GCN 28876; SungHak et al., GCN 28880) at
redshift z = 1.105 (Xu et al., GCN 28847) associated with afterglow of
GRB 201103B (Ursi et al., GCN 28831; Svinkin et al., GCN 28844; Evans et
al., GCN 28858).
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err. UL. Telescope
(mid, days) (s)
2020-11-13 22:58:04 10.21897 R 24*120 21.67 0.16 22.1 ZTSh
The photometry is based on the same stars used in GCNs 28862, 28875, 28883.
Previous IAU Circulars 
