TITLE: GCN CIRCULAR
NUMBER: 35605
SUBJECT: GRB 240123A: Mondy optical afterglow observations
DATE: 24/01/23 15:52:15 GMT
FROM: Alexei Pozanenko at IKI, Moscow <apozanen(a)iki.rssi.ru>
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We observed the field of GRB 231117A (D'Ai et al., GCN 35602) with AZT-33IK telescope of Mondy observatory in R-filter starting on 2024-01-23 (UT) 14:00:48. We clearly detect a new fading object at coordinates (J2000) 13 17 23.87 +60 37 05.3 with uncertainties of 0.2 arcsec which is slightly differ from coordinates reported by UVOT (D'Ai et al., GCN 35602). The object is absent in SDSS catalogue. Preliminary photometry is following
Date UT start t-T0 Exp. Filter OT Err.
(mid, days) (s)
2024-01-23 14:00:48 0.126415 7x120 R 19.07 0.10 20.9
2024-01-23 14:20:48 0.144479 13x120 R 19.25 0.10 21.3
2024-01-23 14:46:49 0.163934 15x120 R 19.37 0.11 21.3
The photometry is based on nearby USNO-B1.0 R2 stars.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35605.
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TITLE: GCN CIRCULAR
NUMBER: 35604
SUBJECT: IceCube-240123A - IceCube observation of a high-energy neutrino candidate track-like event
DATE: 24/01/23 15:06:40 GMT
FROM: Giacomo Sommani at Ruhr-Universität Bochum <gsommani(a)icecube.wisc.edu>
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
On 2024-01-23 at 11:25:36.05 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_Bronze alert stream. The average astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 4.1505 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection.
After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/138890_34080563.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:
Date: 2024-01-23
Time: 11:25:36.05
RA: 357.54 (+1.93, -1.71 deg 90% PSF containment) J2000
Dec: +4.26 (+0.80, -0.76 deg 90% PSF containment) J2000
We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino.
There are no Fermi 4FGL or 3FHL catalog sources in the 90% uncertainty region. The nearest gamma-ray source in either catalog is 4FGL J2349.4+0534 at RA: 357.36 deg, Dec: 5.58 deg (1.33 deg away from the best-fit event position).
The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime
alert point of contact can be reached at roc(a)icecube.wisc.edu
View this GCN Circular online at https://gcn.nasa.gov/circulars/35604.
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TITLE: GCN CIRCULAR
NUMBER: 35603
SUBJECT: Konus-Wind detection of GRB 240112A
DATE: 24/01/23 11:56:59 GMT
FROM: Anna Ridnaia at Ioffe Institute <ridnaia(a)mail.ioffe.ru>
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long-duration GRB 240112A
(GECAM-B detection: Wang and Xiong, GCN 35520;
IPN triangulation: Kozyrev et al., GCN 35554)
triggered Konus-Wind at T0=20481.732 s UT (05:41:21.732).
The burst light curve shows the main multi-peaked episode,
which starts at ~T0-0.2 s and has a total duration of ~2.8 s.
A fainter broad pulse is observed in the KW data from ~T0+113 s
to ~T0+120 s after the main pulse, whose association with
GRB 240112A is supported by the consistent KW ecliptic
latitude response.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240112_T20481/
As observed by Konus-Wind, the burst (main episode)
had a fluence of 7.58(-1.05,+1.13)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0+1.376 s,
of 1.03(-0.19,+0.20)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The spectrum of the main episode
(measured from T0 to T0+8.448 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 = -1.04(-0.21,+0.23),
the high energy photon index beta = -2.67(-0.73,+0.26),
the peak energy Ep = 120(-15,+20) keV
(chi2 = 118/75 dof).
The spectrum of the fainter broad pulse
(measured from T0+106.752 to T0+123.136 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 = -1.67(-0.32,+0.53)
and Ep = 206(-195,+1360) keV (chi2 = 71/86 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.0
(chi2 = 71/85 dof).
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35603.
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TITLE: GCN CIRCULAR
NUMBER: 35602
SUBJECT: GRB 240123A: Swift detection of a burst with a possible optical counterpart
DATE: 24/01/23 11:34:56 GMT
FROM: Antonino D'Ai' at IASF-PA <antonino.dai(a)inaf.it>
A. D'Ai (INAF-IASFPA), E. Ambrosi (INAF-IASFPA),
V. D'Elia (SSDC & INAF-OAR), J.D. Gropp (PSU), J. A. Kennea (PSU),
A. Y. Lien (U Tampa), A. Melandri (INAF-OAR),
K. L. Page (U Leicester), T. M. Parsotan (GSFC/UMBC/CRESSTII) and
B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 11:05:46 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240123A (trigger=1210276). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 199.319, +60.632 which is
RA(J2000) = 13h 17m 16s
Dec(J2000) = +60d 37' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex
structure with a duration of about 25 sec. The peak count rate
was ~500 counts/sec (15-350 keV), at ~5 sec after the trigger.
The XRT began observing the field at 11:08:08.6 UT, 141.8 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 199.34797,
60.61894 which is equivalent to:
RA(J2000) = 13h 17m 23.51s
Dec(J2000) = +60d 37' 08.2"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 69 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at https://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.45 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 2.7
(+2.69/-2.33) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 7.30e-10 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 151 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 13:17:23.25 = 199.3468
DEC(J2000) = +60:37:04.4 = 60.6179
with a 90%-confidence error radius of about 0.2 arc sec. This position is 4.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.9 with a 1-sigma error of about 0.2. No correction has been made for the
expected extinction.
Burst Advocate for this burst is A. D'Ai (antonino.dai AT inaf.it).
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/)
View this GCN Circular online at https://gcn.nasa.gov/circulars/35602.
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TITLE: GCN CIRCULAR
NUMBER: 35601
SUBJECT: Swift GRB240123.46: Global MASTER-Net observations report
DATE: 24/01/23 11:26:57 GMT
FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gress, N.M. Budnev, O.Ershova
(Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich
(Blagoveschensk Educational State University)
MASTER-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the Swift GRB240123.46 (trigger No 1210276,13h 17m 16.56s , +60d 37m 55.2s, R=0.05) errorbox 41 sec after notice time and 121 sec after trigger time at 2024-01-23 11:07:48 UT, with upper limit up to 17.6 mag. Observations started at twilight. The observations began at zenith distance = 68 deg. The sun altitude is -13.5 deg.
The galactic latitude b = 56 deg., longitude l = 117 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2363206
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
131 | MASTER-Tunka | C | 20 | 17.6 |
160 | MASTER-Tunka | C | 20 | 17.6 |
186 | MASTER-Tunka | C | 15 | 17.5 |
209 | MASTER-Tunka | C | 15 | 17.5 |
229 | MASTER-Tunka | C | 10 | 17.4 |
247 | MASTER-Tunka | C | 10 | 17.3 |
265 | MASTER-Tunka | C | 10 | 17.4 |
284 | MASTER-Tunka | C | 10 | 17.1 |
302 | MASTER-Tunka | C | 10 | 17.4 |
320 | MASTER-Tunka | C | 10 | 17.5 |
339 | MASTER-Tunka | C | 10 | 17.4 |
357 | MASTER-Tunka | C | 10 | 17.3 |
375 | MASTER-Tunka | C | 10 | 17.5 |
394 | MASTER-Tunka | C | 10 | 17.4 |
412 | MASTER-Tunka | C | 10 | 17.2 |
430 | MASTER-Tunka | C | 10 | 17.4 |
448 | MASTER-Tunka | C | 10 | 17.3 |
466 | MASTER-Tunka | C | 10 | 17.4 |
486 | MASTER-Tunka | C | 10 | 17.4 |
504 | MASTER-Tunka | C | 10 | 17.4 |
522 | MASTER-Tunka | C | 10 | 17.4 |
541 | MASTER-Tunka | C | 10 | 17.4 |
559 | MASTER-Tunka | C | 10 | 17.4 |
577 | MASTER-Tunka | C | 10 | 17.4 |
595 | MASTER-Tunka | C | 10 | 17.4 |
613 | MASTER-Tunka | C | 10 | 17.4 |
632 | MASTER-Tunka | C | 10 | 17.4 |
651 | MASTER-Tunka | C | 10 | 17.4 |
669 | MASTER-Tunka | C | 10 | 17.4 |
706 | MASTER-Tunka | C | 10 | 17.4 |
724 | MASTER-Tunka | C | 10 | 17.4 |
743 | MASTER-Tunka | C | 10 | 17.4 |
761 | MASTER-Tunka | C | 10 | 17.5 |
781 | MASTER-Tunka | C | 10 | 17.4 |
799 | MASTER-Tunka | C | 10 | 17.5 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35601.
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TITLE: GCN CIRCULAR
NUMBER: 35600
SUBJECT: GRB 240122A: Swift-XRT afterglow detection
DATE: 24/01/23 11:25:05 GMT
FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk>
E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M. Perri (SSDC &
INAF-OAR), D.N. Burrows (PSU), J. D. Gropp (PSU), S. Dichiara (PSU),
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and P.A. Evans
(U. Leicester) reports on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 240122A in a series of observations tiled on the sky. The
total exposure time is 3.6 ks, distributed over 7 tiles; the maximum
exposure at a single sky location was 1.3 ks. The data were collected
between T0+29.5 ks and T0+35.6 ks, and are entirely in Photon Counting
(PC) mode.
Four uncatalogued X-ray sources are detected, of which one ("Source 3")
is above the RASS 3-sigma upper limit at this position, and is
therefore likely the GRB afterglow. Using 930 s of PC mode data and 2
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 = 93.05391, -19.14418 which is equivalent to:
RA (J2000): 06h 12m 12.94s
Dec(J2000): -19d 08' 39.0"
with an uncertainty of 2.9 arcsec (radius, 90% confidence). This
position is 14.5 arcmin from the MAXI position, and it is consistent
with the GOTO optical detection (GCN 35596, Kumar et al. 2024).
The light curve can be modelled with a power-law decay with a decay
index of alpha=2.5 (+0.7, -2.1).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.82 (+0.33, -0.25). The
best-fitting absorption column is consistent with the Galactic value
of 1.0 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum is 3.3 x 10^-11 (3.6 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.0 (+/-0.8) x 10^21 cm^-2
Galactic foreground: 1.0 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.82 (+0.33, -0.25)
If the light curve continues to decay with a power-law decay index of
2.5, the count rate at T+24 hours will be 0.012 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.8 x
10^-13 (4.2 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021645.
The results of the full analysis of the tiled XRT observations are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00119.
This circular is an official product of the Swift-XRT team.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35600.
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TITLE: GCN CIRCULAR
NUMBER: 35599
SUBJECT: GRB 240122A: VLT/X-shooter redshift confirmation
DATE: 24/01/23 09:17:34 GMT
FROM: Andrea Saccardi at Observatoire de Paris <andrea.saccardi(a)obspm.fr>
A. Saccardi (GEPI, Observatoire de Paris), B. Sbarufatti (INAF-OAB), D. B. Malesani (DAWN/NBI & Radboud Univ.), L. Izzo (INAF-OACn & DARK/NBI), A. de Ugarte Postigo (CNRS/OCA & LAM), S. Campana (INAF-OAB), A. J. Levan (Radboud Univ. & Warwick Univ.), D. Hartmann (Clemson University) report on behalf of the Stargate collaboration:
Following the discovery of GOTO24eu/AT2024apy (Kumar et al. 2024, GCN 35596) within the error box of MAXI/GSC GRB 240122A (Negoro et al. 2024, GCN 35593), we acquired a spectrum of the optical counterpart candidate using the ESO/VLT/UT3 (Melipal) equipped with the X-shooter spectrograph. It covers the wavelength range 3000-21000 AA, and consists of 4 exposures of 1200 s each. Observations started at 02:25:37 UT on Jan 23 2024 (~16 hr after the trigger).
We detect a continuum over the entire wavelength range. From the detection of a rather weak Lya absorption at ~5060 AA and multiple absorption features, which we interpret as being due to SiII, CII, MgII, SiIV and CIV, we infer a common redshift of z = 3.162 (consistent with Thoene et al. 2024, GCN 35598). We conclude this is the redshift of the burst. We also note the presence of additional absorption features likely due to multiple intervening systems, one of them very strong at z = 2.757 with a broad Lya at ~4570 AA.
We acknowledge the excellent support from the ESO observing staff in Paranal, in particular Felipe Gaete and Jonathan Smoker.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35599.
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TITLE: GCN CIRCULAR
NUMBER: 35598
SUBJECT: GRB 240122A: Redshift from OSIRIS+/GTC
DATE: 24/01/23 01:06:27 GMT
FROM: Christina Thöne at ASU-CAS <christina.thoene(a)gmail.com>
C. C. Thoene (ASU-CAS), A. de Ugarte Postigo (CNRS/OCA and LAM), J. F. Agui Fernandez (CAHA), L. Izzo (INAF/Capodimonte), J. P. U. Fynbo (DAWN/NBI), N. R. Tanvir (U. Leicester), M. Blazek (CAHA), S. Geier, A. Garcia-Rodriguez, Miguel Rivero Mendez (both GTC) report:
We obtained spectroscopy of the optical afterglow (Kumar et al. GCN 35596) of the MAXI/GSC GRB 240122A (Negoro et al. GCN 35593) with OSIRIS+ at the 10.4m GTC at a mean epoch of 0.5357 days after the GRB. The observation consisted of 3x900s exposures using grism R1000B, which covers the range between 3700 and 7780 AA at a resolving power of about 600. The observation was strongly impacted by the nearby Moon and poor seeing.
A preliminary reduction of the spectrum shows a continuum with multiple absorption features. We determine the redshift of the GRB indentifying Lyman alpha and Lyman beta as well as absorption features of SiII, SiIV, CI, CII, CIV and FeII at a common redshift of z=3.162. We note that the Lyman series is rather weak compared to typical GRB sight lines.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35598.
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TITLE: GCN CIRCULAR
NUMBER: 35597
SUBJECT: GRB 240122A: LT non-detection of GOTO candidate counterpart confirms fading
DATE: 24/01/23 00:32:46 GMT
FROM: Ben Gompertz at U of Birmingham <b.gompertz(a)bham.ac.uk>
B. P. Gompertz (U. Birmingham) reports for a larger collaboration:
We observed the position of the GOTO candidate optical counterpart (Kumar et al, GCN 35596) to the MAXI-detected GRB 240122A (Negoro et al, GCN 35593) with the IO:O optical camera on the 2m robotic Liverpool Telescope. Observations consisted of 3x60s exposures in each of the SDSS r, i, and z filters under seeing of 2.1”, beginning at 23:36:51 UT on 2024-01-22, 13.1 hours after the GRB trigger. We do not detect the source to a 3-sigma limiting magnitude of r(AB) > 19.36. This non-detection indicates fading of more than two magnitudes in the ~12.4 hours since the GOTO detection.
Magnitudes were calibrated to PS1 stars and are not corrected for Galactic extinction.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35597.
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TITLE: GCN CIRCULAR
NUMBER: 35596
SUBJECT: GRB 240122A: GOTO optical counterpart candidate
DATE: 24/01/22 18:50:31 GMT
FROM: Amit Kumar at University of Warwick, UK <amitkundu515(a)gmail.com>
A. Kumar; B. P. Gompertz; K. Ackley; G. Ramsay; R. Starling; M. J. Dyer; J. Lyman; K. Ulaczyk; F. Jimenez-Ibarra; D. O'Neill; D. Steeghs; D. K. Galloway; V. Dhillon; P. O'Brien; K. Noysena; R. Kotak; R. P. Breton; L. K. Nuttall; E. Pall'e and D. Pollacco report on behalf of the GOTO collaboration:
The Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022) serendipitously covered the localisation region of MAXI/GSC detected GRB 240122A (Negoro et al. GCN 35593) at 11:11:43 UT on 2024-01-22 (43.6 minutes after trigger). Each observation consisted of 4x45s exposures in the GOTO L-band (400-700 nm).
Images were processed immediately after acquisition using the GOTO pipeline. Difference imaging was performed using recent survey observations of the same pointings. Source candidates were initially filtered using a classifier (Killestein et al. 2021) and cross-matched against a variety of contextual and minor planet catalogues. Human vetting was carried out in real time on any candidates that passed the above checks.
We identify 1 new optical transient (GOTO24eu/AT2024apy) within the MAXI/GSC uncertainty region. We find no evidence of this source prior to the GRB trigger time in the previous GOTO epoch at 2024-01-21 12:06:42 (22.4 hours prior), to a 5 sigma limiting magnitude of L > 19.8. The source was also not present in the ZTF observations provided by the Lasair broker (Smith et al. 2019), or the ATLAS forced photometry server (Shingles et al. 2021).
Name | RA(J2000) | Dec(J2000) | Filter | Mag(AB)
GOTO24eu/AT2024apy | 06:12:12.91| -19:08:38.81 | L | 17.06 +/- 0.04
Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction.
Observations are ongoing.
GOTO (https://goto-observatory.org) is a network of telescopes that is principally funded by the STFC and operated at the Roque de los Muchachos Observatory on La Palma, Spain, and Siding Spring Observatory in NSW, Australia, on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory & Planetarium, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), the University of Turku, the University of Portsmouth, the University of Manchester and the Instituto de Astrofisica de Canarias (IAC).
View this GCN Circular online at https://gcn.nasa.gov/circulars/35596.
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