GRB 260105A
GCN Circular 43347
Subject
Fermi GRB 260105A: Global MASTER-Net observations report
Date
2026-01-07T03:45:50Z (2 months ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.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-Tunka robotic telescope [1] located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 260105A ( Fermi GBM team, GCN 43335) errorbox 42914 sec after notice time and 42952 sec after trigger time at 2026-01-06 10:43:04 UT, with upper limit up to 19.2 mag. Observations started at twilight. The observations began at zenith distance = 35 deg. The sun altitude is -12.9 deg.
MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 260105A errorbox 1 days 4422 sec after notice time and 1 days 4460 sec after trigger time at 2026-01-07 00:01:32 UT, with upper limit up to 17.2 mag. The observations began at zenith distance = 48 deg. The sun altitude is -50.2 deg.
The galactic latitude b = 4 deg., longitude l = 150 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3096780
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
42983 | 2026-01-06 10:43:04 | MASTER-Tunka | (04h 46m 35.26s , +57d 50m 19.5s) | C | 60 | 19.2 |
42983 | 2026-01-06 10:43:04 | MASTER-Tunka | (04h 47m 41.61s , +57d 41m 18.4s) | C | 60 | 18.7 |
49648 | 2026-01-06 12:34:09 | MASTER- | (04h 54m 01.68s , +56d 22m 44.2s) | C | 60 | 17.3 |
49648 | 2026-01-06 12:34:09 | MASTER- | (04h 52m 23.46s , +56d 56m 52.2s) | C | 60 | 17.2 |
50074 | 2026-01-06 12:41:15 | MASTER- | (04h 24m 20.56s , +60d 44m 34.6s) | C | 60 | 17.0 |
50074 | 2026-01-06 12:41:15 | MASTER- | (04h 26m 06.14s , +60d 10m 24.1s) | C | 60 | 17.5 |
50393 | 2026-01-06 12:46:34 | MASTER- | (04h 53m 57.37s , +56d 22m 05.4s) | C | 60 | 17.6 |
50393 | 2026-01-06 12:46:34 | MASTER- | (04h 52m 21.16s , +56d 56m 07.4s) | C | 60 | 17.2 |
50819 | 2026-01-06 12:53:40 | MASTER- | (04h 26m 00.27s , +60d 10m 01.0s) | C | 60 | 17.5 |
50819 | 2026-01-06 12:53:40 | MASTER- | (04h 24m 16.25s , +60d 44m 10.6s) | C | 60 | 17.0 |
51136 | 2026-01-06 12:58:57 | MASTER- | (04h 53m 56.14s , +56d 21m 50.3s) | C | 60 | 17.3 |
51136 | 2026-01-06 12:58:58 | MASTER- | (04h 52m 21.74s , +56d 55m 48.1s) | C | 60 | 16.9 |
51568 | 2026-01-06 13:06:09 | MASTER- | (04h 26m 02.40s , +60d 10m 25.4s) | C | 60 | 16.5 |
51568 | 2026-01-06 13:06:09 | MASTER- | (04h 24m 20.55s , +60d 44m 28.7s) | C | 60 | 15.9 |
51886 | 2026-01-06 13:11:28 | MASTER- | (04h 53m 50.30s , +56d 22m 14.7s) | C | 60 | 15.8 |
51886 | 2026-01-06 13:11:28 | MASTER- | (04h 52m 17.69s , +56d 56m 07.6s) | C | 60 | 15.6 |
52310 | 2026-01-06 13:18:31 | MASTER- | (04h 25m 59.19s , +60d 10m 12.1s) | C | 60 | 15.8 |
52310 | 2026-01-06 13:18:31 | MASTER- | (04h 24m 19.17s , +60d 44m 11.3s) | C | 60 | 15.4 |
61752 | 2026-01-06 15:55:53 | MASTER-Tunka | (04h 32m 04.80s , +60d 25m 18.6s) | C | 60 | 17.8 |
61752 | 2026-01-06 15:55:53 | MASTER-Tunka | (04h 30m 52.16s , +60d 33m 07.6s) | C | 60 | 17.1 | Coadd
90891 | 2026-01-07 00:01:32 | MASTER-Kislovodsk | (04h 53m 24.59s , +56d 38m 40.5s) | C | 60 | 17.3 |
102412 | 2026-01-07 03:13:34 | MASTER-Kislovodsk | (04h 39m 35.25s , +56d 05m 19.5s) | C | 60 | 16.3 |
102412 | 2026-01-07 03:13:34 | MASTER-Kislovodsk | (04h 32m 17.01s , +56d 24m 49.6s) | C | 60 | 16.8 |
102515 | 2026-01-07 03:15:16 | MASTER-Kislovodsk | (04h 31m 43.02s , +57d 59m 37.8s) | C | 60 | 16.5 |
102515 | 2026-01-07 03:15:16 | MASTER-Kislovodsk | (04h 24m 00.92s , +58d 19m 01.2s) | C | 60 | 16.9 |
102662 | 2026-01-07 03:17:43 | MASTER-Kislovodsk | (04h 23m 11.61s , +59d 52m 00.8s) | C | 60 | 16.7 |
102662 | 2026-01-07 03:17:44 | MASTER-Kislovodsk | (04h 15m 06.89s , +60d 11m 20.5s) | C | 60 | 17.0 |
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 43342
Subject
GRB 260105A: SVOM/GRM observation
Date
2026-01-06T08:30:22Z (2 months ago)
From
Yue Wang <m18509381757@163.com>
Via
Web form
SVOM/GRM team: Yue Wang, Chen-Wei Wang, Hao-Xuan Guo, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)
SVOM/ECLAIRs team: Sebastien Guillot (IRAP)
Report on behalf of the SVOM team:
SVOM/GRM was triggered on-ground by GRB 260105A at 2026-01-05T22:47:16.000 (T0), which is also detected by Fermi/GBM (Fermi GBM team, GCN #43335).
With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multiple pulses with a T90 of 69 +16/-12 s in the 15-5000 keV band.
The SVOM/GRM light curve can be found here:
https://www.bursthub.cn//admin/static/svgrb260105A.png
In addition, the position of this burst, as determined by Fermi/GBM (RA = 64.5, Dec = 55.5, Error = 3.3, GCN #43335), is located at about 85 degrees from the SVOM optical axis, which is outside the ECLAIRs field of view.
With this localization, the time-averaged spectrum from T0-7 to T0+83 s is best fitted by a power law function. The power law index is -1.64 +0.08/-0.07. The event fluence (10-1000 keV) in this time interval is (1.85 +0.20/-0.20)E-05 erg/cm^2.
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. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS.
The SVOM/GRM point of contact for this burst is: Yue Wang (IHEP) (yuewang@ihep.ac.cn)
GCN Circular 43335
Subject
GRB 260105A: Fermi GBM Final Real-time Localization
Date
2026-01-05T22:57:42Z (2 months ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 22:47:11 UT on 5 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260105A (trigger 789346036.667754 / 260105949).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 64.5, Dec = 55.5 (J2000 degrees, equivalent to J2000 04h 17m, 55d 30'), with a statistical uncertainty of 3.3 degrees.
The angle from the Fermi LAT boresight is 99.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260105949/quicklook/glg_skymap_all_bn260105949.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260105949/quicklook/glg_healpix_all_bn260105949.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260105949/quicklook/glg_lc_medres34_bn260105949.gif