GRB 260102A
GCN Circular 43357
Subject
GRB 260102A: Swift-XRT afterglow detection
Date
2026-01-09T06:45:08Z (4 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
M.G. Bernardini (INAF-OAB), S. Dichiara (PSU), J.A. Kennea (PSU), D.N.
Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-OAR) and P.A. Evans (U.
Leicester) reports on behalf of the Swift-XRT team:
Swift-XRT has conducted further observations of the field of the
SVOM/ECLAIRs-detected burst GRB 260102A. The observations now extend
from T0+9.6 ks to T0+582.4 ks and have a total exposure time of 7.3 ks.
The source previously reported, "Source 2", is fading with >3-sigma
significance, and is therefore likely the GRB afterglow. Using 838 s of
PC mode data and 1 UVOT image, we find an enhanced XRT position (using
the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1
catalogue): RA, Dec = 183.94925, +48.25058 which is equivalent to:
RA (J2000): 12h 15m 47.82s
Dec(J2000): +48d 15' 02.1"
with an uncertainty of 6.2 arcsec (radius, 90% confidence). This
position is 2.8 arcmin from the SVOM/ECLAIRs position. The source is
fading with alpha >0.2.
The results of the XRT-team automatic analysis of the likely afterglow
are at https://www.swift.ac.uk/ToO_GRBs/00021896/Source2.php.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021896.
This circular is an official product of the Swift-XRT team.
GCN Circular 43351
Subject
GRB 260102A: AbAO optical observations
Date
2026-01-08T14:28:34Z (4 months ago)
From
Nicolai Pankov at IKI <colinsergesen@gmail.com>
Via
Web form
N. Pankov (IKI), A. Pozanenko (IKI), R. Ya. Inasaridze (AbAO), A. Volnova (IKI) report on behalf of IKI-GRB-FuN:
We performed optical observations of the field of GRB 260102A (XIE et. al, GCN 43295; Evans, GCN 43298; Bernardini et. al, GCN 43304; Yin et. al, GCN 43307; Hamburg, GCN 43308) in the R-filter with the 0.7-meter AS-32 telescope of Abastumani Observatory (AbAO). Two epochs of observations were taken, the first one began on 2026-01-02 19:21:22 UT, i.e. ~0.65 days since trigger. The optical counterpart (Wu et. al, GCN 43300) was not detected in the co-add images of both epochs. The preliminary upper limits and the observation details are given below:
Date UT start t-T0 Exp. Filter OT Err. UL
(mid, days) (s) (3sigma)
2026-01-02 19:21:22 0.65786 72*60 R n/d n/d 20.1
2026-01-03 19:22:18 1.65850 72*60 R n/d n/d 19.8
The photometry was calibrated using nearby stars from USNO-B1.0 and was not corrected for the Galactic extinction. The obtained results do not contradict the optical upper limits from other groups (Antier et. al, GCN 43303; Saccardi et. al, GCN 43305).
GCN Circular 43309
Subject
SVOM GRB260102A: Global MASTER-Net observations report
Date
2026-01-02T18:14:24Z (4 months ago)
Edited On
2026-01-03T21:30:48Z (4 months ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Vladimir Lipunov at Lomonosov Moscow State University <lipunov@sai.msu.ru>
Via
email
V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko,
G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A.Sosnovskij (CrAO),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)
MASTER-Kislovodsk robotic telescope [1] located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the SVOM GRB260102.17 (trigger No 1767326986,12h 15m 31.27s , +48d 15m 29.9s, R=0.0849) errorbox 48331 sec after notice time and 48428 sec after trigger time at 2026-01-02 17:36:54 UT, with upper limit up to 15.1 mag. The observations began at zenith distance = 81 deg. The sun altitude is -41.1 deg.
The galactic latitude b = 68 deg., longitude l = 138 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3093252
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
33488 | 2026-01-02 13:26:23 | MASTER- | (12h 20m 52.08s , +49d 49m 23.4s) | C | 180 | 17.3 |
48459 | 2026-01-02 17:36:54 | MASTER-Kislovodsk | (12h 14m 33.74s , +47d 55m 28.1s) | C | 60 | 15.1 |
50357 | 2026-01-02 18:08:32 | MASTER-Kislovodsk | (12h 14m 30.88s , +47d 52m 14.0s) | C | 60 | 15.5 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
[1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp.
http : // www.pereplet.ru/lipunov/625.html
GCN Circular 43308
Subject
Fermi GBM Sub-Threshold Detection of GRB 260102A
Date
2026-01-02T17:59:21Z (4 months ago)
From
rhamburg@usra.edu
Via
Web form
R. Hamburg (USRA) reports on behalf of the Fermi-GBM Team:
SVOM/ECLAIRs detected GRB 260102A on 2026-01-02 at 04:10:03 UTC (Xie et al 2026, GCN 43295). There was no Fermi-GBM onboard trigger around this event time. An automated, blind search for gamma-ray bursts below the onboard triggering threshold in Fermi-GBM identified no candidates.
The GBM Targeted Search [1], the most sensitive coherent search for GRB-like signals in GBM, identified a transient starting approximately 33 seconds after the ECLAIRs best imaging SNR time at 2026-01-02T04:09:45 (Xie et al 2026, GCN 43295). The transient is detected most significantly on the 32.768 s timescale with a false alarm rate of 1.1e-05 Hz, using a "normal" spectrum (Band function with Epeak = 230 keV, alpha = -1.0, beta = -2.3) for a GRB. The Targeted Search localization is consistent with the ECLAIRs position.
[1] Goldstein et al. 2019 arXiv:1903.12597
GCN Circular 43307
Subject
GRB 260102A: EP-FXT follow-up observation
Date
2026-01-02T15:50:27Z (4 months ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
Y.-H. I. Yin (HKU), X. Mao (NAO, CAS), J. P. Chen (SYSU), and H. W. Pan (NAO, CAS) on behalf of the Einstein Probe (EP) team:
EP-FXT performed a follow-up observation of the SVOM/ECLAIRs-detected burst GRB 260102A (SVOM/sb26010201, Xie et al., GCN 43295) at 2026-01-02 05:43:47 (UTC), about 1.5 hours after the SVOM/ECLAIRs trigger, with an exposure time of 3523 s. One uncatalogued source is detected within the ECLAIRs error circle, and the source is spatially consistent with the counterpart reported in optical and X-ray bands, including detections (Evans et al., GCN 43298; Wu et al., GCN 43300; Bernardini et al., GCN 43304) and upper limits (Antier et al., GCN 43303; Saccardi et al., GCN 43305). Preliminary analysis on this source is automatically conducted, and details are listed as follows.
EPF_J121547.6+481500
RA (J2000): 183.9483
Dec (J2000): 48.2501
Flux: 3.82 x 10^-13 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 4.60 x 10^-14 erg/s/cm2 (1 sigma)
The position uncertainty of the source is about 10 arcsec in radius (90% C.L. statistical and systematic).
Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).
GCN Circular 43305
Subject
GRB 260102A: LCO optical upper limits
Date
2026-01-02T15:02:54Z (4 months ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
A. Saccardi (CEA/Irfu), C. Wu, W. Xie (NAOC), W. Tan (IHEP) report on behalf of the SVOM mission team:
We observed the field of the SVOM GRB 260102A (Xie et al., GCN 43295) with the LCO 1m telescope at McDonald Observatory equipped with the Sinistro instrument.
Our observation started on 2026-01-02 at 08:14:01 UT (about 4.06 hr after the trigger) and we obtained 3x200 s exposures in the Pan-STARRS z filter. In the stacked image, we do not detect any new source within the Swift/XRT source #2 error circle (Bernardini et al., GCN 43304) and at the position of the SVOM/VT optical counterpart (Wu et al., GCN 43300).
We measure the following upper limit calibrated against the Pan-STARRS DR1 catalog, and not corrected for Galactic extinction:
z > 20.1 AB (3-sigma, mid-time 4.13 hr after the trigger).
This project is funded by the SVOM collaboration.
GCN Circular 43304
Subject
GRB 260102A: Swift-XRT observations
Date
2026-01-02T14:37:52Z (4 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
M.G. Bernardini (INAF-OAB), S. Dichiara (PSU), J.A. Kennea (PSU), D.N.
Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-OAR) and P.A. Evans (U.
Leicester) reports on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
SVOM/ECLAIRs-detected burst GRB 260102A, collecting 2.8 ks of Photon
Counting (PC) mode data between T0+9.6 ks and T0+26.1 ks.
One uncatalogued X-ray source has been detected within the estimated
3-sigma SVOM/ECLAIRs error region (502 arcsec), it is below the RASS
limit and shows no definitive signs of fading. Therefore, at the
present time we cannot confirm this as the afterglow. Details of this
source are given below:
Source 2:
RA (J2000.0): 183.9493 = 12h 15m 47.82s
Dec (J2000.0): +48.2506 = +48d 15' 02.1"
Error: 6.2 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: (6.3 [+2.2, -1.8])e-3 ct s^-1
Distance: 167 arcsec from SVOM/ECLAIRs position.
Flux: (1.72 [+0.59, -0.48])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
SVOM/VT detected an optical counterpart consistent with this X-ray
source (GCN Circ. 43300).
An uncatalogued source was also detected, however this was too far from
the GRB position to be the afterglow.
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021896.
This circular is an official product of the Swift-XRT team.
GCN Circular 43303
Subject
GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
Date
2026-01-02T14:09:15Z (4 months ago)
From
Dalya Akl at New York University Abu Dhabi <dka2010@nyu.edu>
Via
Web form
Sarah Antier (IJCLAB), William H. Lee (UNAM), Dalya Akl (NYUAD), Alan M. Watson (UNAM), Stéphane Basa (UAR Pytheas), Jean-Luc Atteia (IRAP), Camila Angulo (UNAM), Rosa L. Becerra (UNAM), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), Jean-Grégoire Ducoin (CPPM), Francis Fortin (IRAP), Leonardo García García (UNAM), Ramandeep Gill (UNAM), Noémie Globus (UNAM), Nikos Mandarakas (LAM), Kin Ocelotl López (UNAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Enrique Moreno Méndez (UNAM), Margarita Pereyra (UNAM), Ny Avo Rakotondrainibe (LAM), Fredd Sánchez Álvarez (UNAM), Benjamin Schneider (LAM), Antonio de Ugarte Postigo (LAM), Wenjin Xie (NAOC), and Wenjun Tan (IHEP) report:
We imaged the field of the SVOM GRB 260102A (Xie et al., GCN Circ. 43295) using the DDRAGO wide-field imager on the SVOM/COLIBRÍ (FM-GFT) telescope. We observed from 2026-01-02 13:04 to 13:25 UTC (about 8.9 hours after the trigger) and obtained 18 minutes of simultaneous exposure in the r/z filters.
The data were reduced and coadded with the COLIBRÍ ASU pipeline and analyzed with STDWeb/STDPipe (Karpov 2025). The photometry was calibrated using nearby stars from the PanSTARRS DR1 catalog, is in the AB system, and is not corrected for Galactic extinction.
We did not detect the optical counterpart reported by Wu et al. (GCN Circ. 43300) to preliminary 3-sigma magnitude limits of:
r > 23.5
z > 22.8
We thank the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir and the COLIBRÍ and DDRAGO engineering teams.
COLIBRÍ is an astronomical observatory developed and operated jointly by France (AMU, CNES and CNRS) and Mexico (UNAM and SECIHTI). It is located at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir, Baja California, Mexico.
GCN Circular 43300
Subject
GRB 260102A: SVOM/VT optical counterpart
Date
2026-01-02T12:45:56Z (4 months ago)
Edited On
2026-01-02T15:22:42Z (4 months ago)
From
Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Huali Li at at NAOC, SVOM <lhl@nao.cas.cn>
Via
Web form
C. Wu, H. L. Li, L. P. Xin, Y. L. Qiu, Y. N. Ma, Z. H. Yao, X. H. Han, J. Wang, Y. Xu, P. P. Zhang, W. J. Xie, Y. J. Xiao, L. Lan, J. R. Xu, H. B. Cai, J. S. Deng, J. Y. Wei (NAOC), J. Palmerio (CEA), W. J. Tan (IHEP) report on behalf of the SVOM team.
SVOM performed an automatic slew on the burst GRB 260102A triggered by SVOM/ECLAIRs (sb26010201, Xie et al., GCN 43295) in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously. The observation began at 2026-01-02T04:13:40, i.e., 217 sec post trigger.
An optical uncatalogued source was detected within errorbox of ECLAIRs (Xie et al., GCN 43295) and Swift-XRT source #2 (Evans et al., GCN 43298), compared to the Legacy survey catalog. The position is at R.A., Dec. = 183.95015, 48.25116 degrees, equivalent to:
R.A. (J2000) = 12:15:48.03
Dec. (J2000) = 48:15:04.18
with an uncertainty of 0.5 arcsec.
The magnitudes are:
Mid_time Band Exposure Time Magnitude (AB)
242 sec VT_B 50 sec 19.98+/-0.06
242 sec VT_R 50 sec 18.46+/-0.03
872 sec VT_B 50 sec 21.40+/-0.16
872 sec VT_R 50 sec 20.21+/-0.10
Our photometry was not corrected for Galactic extinction.
More follow-ups for this burst are encouraged.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS.
GCN Circular 43298
Subject
GRB 260102A: Swift ToO observations
Date
2026-01-02T06:48:54Z (4 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the SVOM/ECLAIRs-detected event
GRB 260102A. Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021896
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 SVOM/ECLAIRs 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 43295
Subject
GRB 260102A: SVOM detection of a burst
Date
2026-01-02T04:43:22Z (4 months ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
Wenjin XIE (NAOC), Wenjun TAN (IHEP), Donhua ZHAO (NAOC), Chenwei WANG (IHEP) report on behalf of the SVOM mission team:
At 2026-01-02T04:10:03 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 260102A (SVOM burst-id sb26010201).
The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network.
The burst was detected both by the Count-Rate Trigger (CRT) and the Image Trigger (IMT), which produced a sequence of 14 alerts. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 16.44 in the [8-120] keV energy band over a time window of 40.96 seconds starting at 2026-01-02T04:09:45.
The localization of the best alert is R.A., Dec. 183.8803, 48.2583 degrees:
R.A. (J2000) = 12h15m31.28s
Dec. (J2000) = 48d15m29.77s
with a 90% confidence level (C.L.) radius of 5.09 arcmin (including systematic error of 2 arcmin added in quadrature).
SVOM/GRM detected the burst also. The SVOM/GRM light curve can be found here:
https://www.bursthub.cn//admin/static/svgrb260102A.png
SVOM slewed to the burst. SVOM/MXT and VT began observing the field after the slew. The analysis of the data will be published in a future circular.
The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. SVOM/ECLAIRs was developed jointly by CNES, CEA-IRFU, CNRS-IRAP, CNRS-APC. SVOM/GRM was developed by the Institute of High Energy Physics (IHEP) of CAS. SVOM/MXT was developed jointly by CNES, CEA-IRFU, CNRS-IJCLab, University of Leicester, MPE.
The Burst Advocate (BA) on shift for this alert is Wenjin XIE: xiewj@bao.ac.cn.
Please contact the BA by email if you require additional information.