January 2026 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 41419] EP260105a: Global MASTER-Net observations report
by GCN Circulars 05 Jan '26

05 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43328 SUBJECT: EP260105a: Global MASTER-Net observations report DATE: 26/01/05 06:36:38 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) was pointed to the EP260105a ( EP Team et al., GCN 43327) errorbox 302 sec after trigger time at 2026-01-05 05:55:32 UT, with upper limit up to 17.7 mag. The observations began at zenith distance = 76 deg. The sun altitude is -33.4 deg. The galactic latitude b = 79 deg., longitude l = 235 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3096319 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 333 | 2026-01-05 05:55:32 | MASTER-OAFA | (12h 04m 39.81s , +22d 45m 13.6s) | C | 60 | 17.0 | 404 | 2026-01-05 05:56:38 | MASTER-OAFA | (12h 04m 39.97s , +22d 45m 19.5s) | C | 70 | 17.2 | 490 | 2026-01-05 05:57:55 | MASTER-OAFA | (12h 04m 40.18s , +22d 45m 26.3s) | C | 90 | 17.3 | 597 | 2026-01-05 05:59:31 | MASTER-OAFA | (12h 04m 40.39s , +22d 45m 34.0s) | C | 110 | 17.3 | 723 | 2026-01-05 06:01:28 | MASTER-OAFA | (12h 04m 40.60s , +22d 45m 42.6s) | C | 130 | 17.4 | 874 | 2026-01-05 06:03:44 | MASTER-OAFA | (12h 04m 40.84s , +22d 45m 52.0s) | C | 160 | 17.5 | 991 | 2026-01-05 06:06:30 | MASTER-OAFA | (12h 04m 41.03s , +22d 45m 59.4s) | C | 60 | 17.5 | 1056 | 2026-01-05 06:07:36 | MASTER-OAFA | (12h 04m 41.10s , +22d 46m 03.1s) | C | 60 | 17.5 | 1121 | 2026-01-05 06:08:41 | MASTER-OAFA | (12h 04m 41.18s , +22d 46m 07.0s) | C | 60 | 17.5 | 1188 | 2026-01-05 06:09:47 | MASTER-OAFA | (12h 04m 41.28s , +22d 46m 10.9s) | C | 60 | 17.5 | 1253 | 2026-01-05 06:10:53 | MASTER-OAFA | (12h 04m 41.36s , +22d 46m 14.7s) | C | 60 | 17.6 | 1319 | 2026-01-05 06:11:58 | MASTER-OAFA | (12h 04m 41.43s , +22d 46m 18.6s) | C | 60 | 17.7 | 1385 | 2026-01-05 06:13:05 | MASTER-OAFA | (12h 04m 41.51s , +22d 46m 22.1s) | C | 60 | 17.7 | 1451 | 2026-01-05 06:14:10 | MASTER-OAFA | (12h 04m 41.60s , +22d 46m 25.6s) | C | 60 | 17.6 | 1516 | 2026-01-05 06:15:16 | MASTER-OAFA | (12h 04m 41.63s , +22d 46m 29.0s) | C | 60 | 17.7 | 1582 | 2026-01-05 06:16:22 | MASTER-OAFA | (12h 04m 41.67s , +22d 46m 32.3s) | C | 60 | 17.7 | 1648 | 2026-01-05 06:17:27 | MASTER-OAFA | (12h 04m 41.73s , +22d 46m 35.5s) | C | 60 | 17.7 | 1714 | 2026-01-05 06:18:33 | MASTER-OAFA | (12h 04m 41.76s , +22d 46m 38.8s) | C | 60 | 17.7 | 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/43328. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41418] EP260105a: Einstein Probe detection of an X-ray transient
by GCN Circulars 05 Jan '26

05 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43327 SUBJECT: EP260105a: Einstein Probe detection of an X-ray transient DATE: 26/01/05 06:17:04 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> H. Zhou (PMO, CAS), Z. C. Zou (NJU), D. Y. Li, Z. X. Ling (NAO, CAS) on behalf of the Einstein Probe (EP) team: We report on the detection of an X-ray transient by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission, designated EP260105a. The transient triggered EP-WXT (ID: 01709250995) at 2026-01-05T05:50:30 (UTC). The WXT position of the source is R.A. = 181.036 deg, DEC = 22.723 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). A follow-up observation with the Follow-up X-ray Telescope (FXT) was performed automatically. Within the WXT error circle, an uncatalogued X-ray source was detected at R.A. = 181.0158 deg, DEC = 22.7089 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic). Further information will be updated when the telemetry data is received. 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). View this GCN Circular online at https://gcn.nasa.gov/circulars/43327. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41417] GRB 260103A: Insight-HXMT/HE detection
by GCN Circulars 05 Jan '26

05 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43326 SUBJECT: GRB 260103A: Insight-HXMT/HE detection DATE: 26/01/05 05:48:29 GMT FROM: Xinghao Luo at IHEP <2952704891(a)qq.com> Xing-hao Luo, Chen-Wei Wang, Chao Zheng, and Shao-Lin Xiong (IHEP) report on behalf of the Insight-HXMT team: At 2026-01-03T01:46:53.800 (T0), Insight-HXMT/HE detected the long burst GRB 260103A, which is also detected by SVOM/GRM (Chen-Wei Wang et.al., GCN #43314) , GECAM-B (Xing-Hao Luo et.al., GCN #43317) The Insight-HXMT/HE light curve mainly consists of multiple pulses with a T90 of 4.6 +1.8/-1.0 s. The 1s peak rate, measured from T0-0.25 s, is 1848 cnts/sec. Insight-HXMT/HE detected a total of 4704 counts form this burst. The HXMT/HE light curve can be found here: https://www.bursthub.cn//admin/static/hxmtgrb260103A.png All measurements above are made with the CsI detectors of Insight-HXMT/HE operating in the regular mode with the energy range of about 60-900 keV (deposited 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 funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://www.hxmt.org View this GCN Circular online at https://gcn.nasa.gov/circulars/43326. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41416] GRB 260104A: COLIBRÍ optical upper limits
by GCN Circulars 05 Jan '26

05 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43325 SUBJECT: GRB 260104A: COLIBRÍ optical upper limits DATE: 26/01/05 04:32:13 GMT FROM: globus(a)astro.unam.mx Noémie Globus (UNAM), Jean-Luc Atteia (IRAP), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Alan M. Watson (UNAM), Dalya Akl (NYUAD), Camila Angulo (UNAM), Sarah Antier (IJCLAB), 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), 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) and Antonio de Ugarte Postigo (LAM), report: We imaged the field of GRB 260104A (Caputo et al., GCN Circ. 43315; Evans et al., GCN Circ. 43319; Kennea et al., GCN Circ. 43320), using the DDRAGO two-channel wide-field imager on the COLIBRÍ telescope. We observed from 2026-01-05 at 01:46 to 02:44 UTC (from 20.16 to 21.12 hr after the trigger) and obtained 41 minutes of simultaneous exposure in the r and 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 was not corrected for Galactic extinction. In the stacked image, we do not detect any new source at the XRT uncertainty region (Caputo et al., GCN Circ. 43315) down to the following 5-sigma limit: r > 21.90, z > 20.96. 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/43325. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41415] GRB 260104C: Fermi GBM Final Real-time Localization
by GCN Circulars 05 Jan '26

05 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43324 SUBJECT: GRB 260104C: Fermi GBM Final Real-time Localization DATE: 26/01/05 00:08:31 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 23:57:57 UT on 4 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260104C (trigger 789263882.41794 / 260104999). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 312.7, Dec = -26.1 (J2000 degrees, equivalent to J2000 20h 50m, -26d 06'), with a statistical uncertainty of 9.3 degrees. The angle from the Fermi LAT boresight is 101.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260104999/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260104999/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260104999/… View this GCN Circular online at https://gcn.nasa.gov/circulars/43324. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41414] Fermi GRB 260104B: Global MASTER-Net observations report
by GCN Circulars 04 Jan '26

04 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43323 SUBJECT: Fermi GRB 260104B: Global MASTER-Net observations report DATE: 26/01/04 18:30:45 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> 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) started inspect of the Fermi GRB 260104B ( Fermi GBM team, GCN 43316) errorbox 41510 sec after notice time and 41543 sec after trigger time at 2026-01-04 17:22:21 UT, with upper limit up to 16.9 mag. The observations began at zenith distance = 76 deg. The sun altitude is -38.2 deg. The galactic latitude b = -38 deg., longitude l = 231 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3095661 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 2242 | 2026-01-04 06:26:49 | MASTER- | (04h 57m 27.88s , -27d 20m 35.2s) | C | 60 | 16.2 | 2311 | 2026-01-04 06:27:58 | MASTER- | (05h 06m 32.28s , -27d 20m 26.9s) | C | 60 | 15.5 | 2523 | 2026-01-04 06:31:30 | MASTER- | (04h 39m 55.89s , -27d 23m 49.4s) | C | 60 | 15.2 | 2666 | 2026-01-04 06:33:53 | MASTER- | (04h 52m 07.50s , -25d 29m 24.1s) | C | 60 | 16.5 | 2666 | 2026-01-04 06:33:53 | MASTER- | (04h 53m 11.08s , -26d 03m 29.8s) | C | 60 | 16.5 | 2736 | 2026-01-04 06:35:03 | MASTER- | (05h 01m 14.80s , -25d 28m 03.2s) | C | 60 | 16.9 | 2736 | 2026-01-04 06:35:03 | MASTER- | (05h 02m 18.57s , -26d 02m 09.0s) | C | 60 | 16.7 | 2808 | 2026-01-04 06:36:15 | MASTER- | (04h 52m 28.51s , -31d 45m 31.6s) | C | 60 | 16.2 | 2808 | 2026-01-04 06:36:15 | MASTER- | (04h 51m 23.06s , -31d 11m 26.1s) | C | 60 | 16.2 | 2878 | 2026-01-04 06:37:25 | MASTER- | (05h 00m 58.96s , -31d 08m 33.7s) | C | 60 | 16.7 | 2878 | 2026-01-04 06:37:25 | MASTER- | (05h 02m 04.41s , -31d 42m 39.1s) | C | 60 | 16.4 | 2948 | 2026-01-04 06:38:36 | MASTER- | (04h 57m 21.81s , -27d 22m 07.2s) | C | 60 | 17.0 | 3018 | 2026-01-04 06:39:45 | MASTER- | (05h 07m 35.96s , -27d 54m 01.5s) | C | 60 | 15.6 | 3229 | 2026-01-04 06:43:16 | MASTER- | (04h 40m 01.43s , -27d 26m 00.8s) | C | 60 | 13.6 | 3370 | 2026-01-04 06:45:37 | MASTER- | (04h 53m 12.96s , -26d 04m 26.6s) | C | 60 | 14.2 | 3440 | 2026-01-04 06:46:47 | MASTER- | (05h 02m 17.23s , -26d 01m 36.0s) | C | 60 | 14.9 | 3864 | 2026-01-04 06:53:51 | MASTER- | (04h 55m 49.13s , -29d 51m 20.9s) | C | 60 | 14.7 | 3934 | 2026-01-04 06:55:01 | MASTER- | (04h 41m 00.45s , -28d 01m 07.5s) | C | 60 | 15.3 | 5582 | 2026-01-04 07:22:29 | MASTER- | (04h 49m 02.68s , -27d 27m 05.8s) | C | 60 | 14.9 | 5722 | 2026-01-04 07:24:49 | MASTER- | (05h 02m 07.90s , -26d 07m 35.4s) | C | 60 | 15.9 | 5794 | 2026-01-04 07:26:01 | MASTER- | (04h 51m 20.48s , -31d 16m 47.1s) | C | 60 | 15.7 | 5871 | 2026-01-04 07:27:18 | MASTER- | (05h 01m 55.81s , -31d 48m 03.9s) | C | 60 | 15.6 | 5871 | 2026-01-04 07:27:18 | MASTER- | (05h 00m 51.97s , -31d 14m 17.1s) | C | 60 | 15.8 | 5941 | 2026-01-04 07:28:29 | MASTER- | (04h 58m 23.48s , -28d 02m 10.3s) | C | 60 | 15.6 | 5941 | 2026-01-04 07:28:29 | MASTER- | (04h 57m 21.23s , -27d 28m 23.1s) | C | 60 | 15.7 | 6011 | 2026-01-04 07:29:38 | MASTER- | (05h 07m 38.07s , -27d 59m 29.0s) | C | 60 | 15.8 | 6011 | 2026-01-04 07:29:38 | MASTER- | (05h 06m 35.66s , -27d 25m 41.7s) | C | 60 | 15.9 | 6225 | 2026-01-04 07:33:12 | MASTER- | (04h 39m 56.85s , -27d 30m 34.5s) | C | 60 | 15.5 | 6294 | 2026-01-04 07:34:21 | MASTER- | (04h 50m 03.23s , -28d 04m 16.2s) | C | 60 | 15.5 | 6294 | 2026-01-04 07:34:21 | MASTER- | (04h 49m 01.46s , -27d 30m 29.0s) | C | 60 | 15.6 | 6364 | 2026-01-04 07:35:31 | MASTER- | (04h 53m 11.10s , -26d 09m 47.5s) | C | 60 | 15.6 | 6364 | 2026-01-04 07:35:31 | MASTER- | (04h 52m 09.83s , -25d 36m 00.6s) | C | 60 | 15.7 | 6574 | 2026-01-04 07:39:01 | MASTER- | (05h 00m 52.79s , -31d 15m 18.7s) | C | 60 | 15.2 | 6715 | 2026-01-04 07:41:22 | MASTER- | (05h 06m 28.06s , -27d 26m 49.6s) | C | 60 | 15.8 | 7698 | 2026-01-04 07:57:45 | MASTER- | (04h 50m 05.69s , -28d 04m 34.9s) | C | 60 | 15.6 | 7768 | 2026-01-04 07:58:55 | MASTER- | (04h 53m 00.95s , -26d 11m 14.1s) | C | 60 | 15.9 | 7768 | 2026-01-04 07:58:55 | MASTER- | (04h 52m 00.40s , -25d 37m 26.0s) | C | 60 | 16.1 | 7838 | 2026-01-04 08:00:05 | MASTER- | (05h 02m 02.71s , -26d 09m 10.2s) | C | 60 | 16.2 | 41574 | 2026-01-04 17:22:21 | MASTER-Kislovodsk | (04h 50m 32.18s , -29d 17m 24.6s) | C | 60 | 16.5 | 41574 | 2026-01-04 17:22:21 | MASTER-Kislovodsk | (04h 45m 43.40s , -28d 54m 23.9s) | C | 60 | 16.0 | 41665 | 2026-01-04 17:23:52 | MASTER-Kislovodsk | (04h 51m 16.48s , -30d 47m 33.2s) | C | 60 | 15.9 | 41665 | 2026-01-04 17:23:52 | MASTER-Kislovodsk | (04h 56m 09.74s , -31d 10m 40.4s) | C | 60 | 16.4 | 41765 | 2026-01-04 17:25:32 | MASTER-Kislovodsk | (04h 40m 47.65s , -27d 00m 22.3s) | C | 60 | 16.1 | 41765 | 2026-01-04 17:25:32 | MASTER-Kislovodsk | (04h 45m 32.33s , -27d 23m 21.7s) | C | 60 | 16.6 | 41864 | 2026-01-04 17:27:11 | MASTER-Kislovodsk | (04h 42m 14.12s , -31d 12m 16.4s) | C | 60 | 16.5 | 41864 | 2026-01-04 17:27:11 | MASTER-Kislovodsk | (04h 37m 20.17s , -30d 49m 11.9s) | C | 60 | 16.0 | 41971 | 2026-01-04 17:28:58 | MASTER-Kislovodsk | (05h 04m 22.64s , -29d 18m 38.3s) | C | 60 | 16.5 | 41971 | 2026-01-04 17:28:58 | MASTER-Kislovodsk | (04h 59m 34.30s , -28d 55m 32.0s) | C | 60 | 16.1 | 42065 | 2026-01-04 17:30:32 | MASTER-Kislovodsk | (04h 32m 06.66s , -28d 53m 31.4s) | C | 60 | 16.1 | 42065 | 2026-01-04 17:30:32 | MASTER-Kislovodsk | (04h 36m 56.06s , -29d 16m 33.1s) | C | 60 | 16.7 | 42164 | 2026-01-04 17:32:11 | MASTER-Kislovodsk | (04h 48m 10.69s , -33d 06m 19.4s) | C | 60 | 16.7 | 42164 | 2026-01-04 17:32:11 | MASTER-Kislovodsk | (04h 43m 11.58s , -32d 43m 08.2s) | C | 60 | 16.0 | 42271 | 2026-01-04 17:33:58 | MASTER-Kislovodsk | (04h 54m 05.21s , -25d 28m 29.6s) | C | 60 | 16.7 | 42271 | 2026-01-04 17:33:58 | MASTER-Kislovodsk | (04h 49m 24.55s , -25d 05m 31.4s) | C | 60 | 16.3 | 43000 | 2026-01-04 17:46:07 | MASTER-Kislovodsk | (05h 02m 25.68s , -33d 04m 15.6s) | C | 60 | 16.2 | 43000 | 2026-01-04 17:46:07 | MASTER-Kislovodsk | (04h 57m 26.37s , -32d 41m 10.1s) | C | 60 | 15.7 | 43101 | 2026-01-04 17:47:48 | MASTER-Kislovodsk | (05h 05m 24.66s , -30d 48m 57.6s) | C | 60 | 16.0 | 43101 | 2026-01-04 17:47:48 | MASTER-Kislovodsk | (05h 10m 18.41s , -31d 12m 01.4s) | C | 60 | 16.4 | 43197 | 2026-01-04 17:49:24 | MASTER-Kislovodsk | (04h 23m 27.29s , -30d 47m 05.7s) | C | 60 | 16.3 | 43197 | 2026-01-04 17:49:24 | MASTER-Kislovodsk | (04h 28m 22.30s , -31d 10m 02.1s) | C | 60 | 16.4 | 43296 | 2026-01-04 17:51:03 | MASTER-Kislovodsk | (05h 07m 45.12s , -27d 01m 13.2s) | C | 60 | 16.3 | 43296 | 2026-01-04 17:51:03 | MASTER-Kislovodsk | (05h 12m 29.83s , -27d 24m 09.3s) | C | 60 | 16.9 | 43392 | 2026-01-04 17:52:39 | MASTER-Kislovodsk | (05h 02m 48.98s , -25d 05m 52.7s) | C | 60 | 16.4 | 43392 | 2026-01-04 17:52:39 | MASTER-Kislovodsk | (05h 07m 30.08s , -25d 28m 45.0s) | C | 60 | 16.9 | 43489 | 2026-01-04 17:54:16 | MASTER-Kislovodsk | (04h 28m 56.26s , -32d 41m 38.2s) | C | 60 | 16.1 | 43489 | 2026-01-04 17:54:16 | MASTER-Kislovodsk | (04h 33m 56.47s , -33d 04m 37.0s) | C | 60 | 16.8 | 43611 | 2026-01-04 17:56:18 | MASTER-Kislovodsk | (04h 45m 14.35s , -23d 12m 04.0s) | C | 60 | 16.5 | 43611 | 2026-01-04 17:56:18 | MASTER-Kislovodsk | (04h 49m 52.66s , -23d 34m 50.9s) | C | 60 | 16.9 | 43713 | 2026-01-04 17:58:00 | MASTER-Kislovodsk | (05h 13m 17.23s , -28d 55m 26.7s) | C | 60 | 15.9 | 43713 | 2026-01-04 17:58:00 | MASTER-Kislovodsk | (05h 18m 06.31s , -29d 18m 24.5s) | C | 60 | 16.5 | 43812 | 2026-01-04 17:59:39 | MASTER-Kislovodsk | (04h 18m 26.58s , -28d 53m 32.5s) | C | 60 | 16.5 | 43812 | 2026-01-04 17:59:39 | MASTER-Kislovodsk | (04h 23m 17.31s , -29d 16m 23.2s) | C | 60 | 16.7 | 43913 | 2026-01-04 18:01:20 | MASTER-Kislovodsk | (04h 23m 04.76s , -25d 05m 38.8s) | C | 60 | 16.4 | 43913 | 2026-01-04 18:01:20 | MASTER-Kislovodsk | (04h 27m 47.39s , -25d 28m 24.3s) | C | 60 | 16.7 | 44015 | 2026-01-04 18:03:02 | MASTER-Kislovodsk | (04h 58m 17.18s , -23d 12m 44.0s) | C | 60 | 16.5 | 44015 | 2026-01-04 18:03:02 | MASTER-Kislovodsk | (05h 02m 55.78s , -23d 35m 30.2s) | C | 60 | 16.9 | 44116 | 2026-01-04 18:04:43 | MASTER-Kislovodsk | (04h 49m 39.60s , -34d 36m 43.5s) | C | 60 | 16.3 | 44116 | 2026-01-04 18:04:43 | MASTER-Kislovodsk | (04h 54m 45.85s , -34d 59m 47.5s) | C | 60 | 16.6 | 44642 | 2026-01-04 18:13:29 | MASTER-Kislovodsk | (04h 35m 04.96s , -34d 37m 22.1s) | C | 60 | 16.2 | 44642 | 2026-01-04 18:13:29 | MASTER-Kislovodsk | (04h 40m 12.32s , -35d 00m 09.5s) | C | 60 | 16.5 | 44743 | 2026-01-04 18:15:10 | MASTER-Kislovodsk | (05h 11m 49.15s , -32d 42m 49.7s) | C | 60 | 15.9 | 44743 | 2026-01-04 18:15:10 | MASTER-Kislovodsk | (05h 16m 49.49s , -33d 05m 40.2s) | C | 60 | 16.3 | 44863 | 2026-01-04 18:17:10 | MASTER-Kislovodsk | (04h 32m 07.30s , -23d 10m 34.0s) | C | 60 | 16.6 | 44863 | 2026-01-04 18:17:10 | MASTER-Kislovodsk | (04h 36m 47.11s , -23d 33m 05.7s) | C | 60 | 16.9 | 44964 | 2026-01-04 18:18:51 | MASTER-Kislovodsk | (05h 04m 19.98s , -34d 35m 48.0s) | C | 60 | 15.1 | 44964 | 2026-01-04 18:18:51 | MASTER-Kislovodsk | (05h 09m 26.52s , -34d 58m 39.2s) | 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/43323. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41413] Swift GRB 260104A: Global MASTER-Net observations report
by GCN Circulars 04 Jan '26

04 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43322 SUBJECT: Swift GRB 260104A: Global MASTER-Net observations report DATE: 26/01/04 16:48:28 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> 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 Swift GRB 260104A ( R. Caputo et al., GCN 43315) errorbox 39152 sec after notice time and 39173 sec after trigger time at 2026-01-04 16:29:55 UT, with upper limit up to 15.0 mag. The observations began at zenith distance = 82 deg. The sun altitude is -28.6 deg. The galactic latitude b = -58 deg., longitude l = 36 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3095622 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 39263 | MASTER-Kislovodsk | C | 180 | 13.5 | 39263 | MASTER-Kislovodsk | C | 180 | 14.3 | 39471 | MASTER-Kislovodsk | C | 180 | 13.5 | 39471 | MASTER-Kislovodsk | C | 180 | 14.1 | 39687 | MASTER-Kislovodsk | C | 180 | 14.2 | 39687 | MASTER-Kislovodsk | C | 180 | 15.0 | 39903 | MASTER-Kislovodsk | C | 180 | 14.7 | 39903 | MASTER-Kislovodsk | C | 180 | 15.0 | 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/43322. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41412] GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
by GCN Circulars 04 Jan '26

04 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43321 SUBJECT: GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits DATE: 26/01/04 15:26:20 GMT FROM: Dr. Kaushik Chatterjee at SWIFAR, Yunnan University <mails.kc.physics(a)gmail.com> Kaushik Chatterjee, Guowang Du, Yu Pan, Yifei Ding, Guangya Zeng, Brajesh Kumar, Yuan Fang, Jinghua Zhang, Xingzhu Zou, Xinlei Chen, Xufeng Zhu, Tao Wang, Xinzhong Er, Yuanpei Yang, Xiangkun Liu, Xiaowei Liu (SWIFAR, YNU) report on behalf of the Mephisto Team: The EP-WXT trigger 01709250693 (trigger time 2025-12-30T01:22:21), identified as EP251230a/GRB251230A (Lanava et al., GCN 43252; Li et al. GCN 43255; Wang. C. et al., GCN 43259; Osborne et al., GCN 43263) was observed with the following facility of the Yunnan University, located at the Lijiang Observatory: the 1.6m Multi-channel Photometric Survey Telescope (Mephisto). A set of simultaneous multi-band (ugi and vrz) frames were collected starting from 2025-12-30 UTC19:34:28 (~ 16.9 hr after the trigger) and continued till 2025-12-30 UTC20:00:18. The optical counterpart reported previously (Busmann et al., GCN 43258; Masi et al., GCN 43260; Ghosh et al., GCN 43262; Ma et al., GCN 43265) was not detected in our stacked frames and the upper limits (5 sigma) are listed below. --------------------------------------------------- Start_Time(UT) | Band | Exp(s) | LimMag (AB) --------------------------------------------------- 2025-12-30T19:34:28 | u | 45.0*7 | >21.08 2025-12-30T19:54:43 | v | 45.0*6 | >20.89 2025-12-30T19:34:30 | g | 45.0*6 | >21.36 2025-12-30T19:54:45 | r | 45.0*6 | >21.38 2025-12-30T19:34:30 | i | 45.0*7 | >21.04 2025-12-30T19:54:44 | z | 45.0*6 | >20.32 --------------------------------------------------- Mephisto (Multi-channel Photometric Survey Telescope) is a 1.6-m wide-field multi-channel telescope, the first of its type in the world, capable of imaging the same field of view in three optical bands simultaneously. The facility is operated by the South-Western Institute for Astronomy Research (SWIFAR), Yunnan University. It provides real-time, high-quality colors of stellar objects. The Mephisto mosaic cameras were installed in October 2025. The first light was achieved in all three channels on 10 October 2025 and presently, these are under the commissioning phase. All the data have been reduced by the Mephisto data processing pipeline. Here, we note that the current data processing pipeline is still at a preliminary stage, with flux calibration precision in each band at the level of about 5% or even higher. View this GCN Circular online at https://gcn.nasa.gov/circulars/43321. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41411] GRB 260104A: Swift-XRT refined Analysis
by GCN Circulars 04 Jan '26

04 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43320 SUBJECT: GRB 260104A: Swift-XRT refined Analysis DATE: 26/01/04 14:58:50 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> J.A. Kennea (PSU), D.N. Burrows (PSU), S. Lanava (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-OAR), M. Perri (SSDC & INAF-OAR) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 6.3 ks of XRT data for GRB 260104A, from 101 s to 28.3 ks after the trigger. The data comprise 10 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The late-time light curve (from T0+5.1 ks) can be modelled with a power-law decay with a decay index of alpha=1.22 (+0.26, -0.23). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.78 (+0.16, -0.10). The best-fitting absorption column is 3.55 (+3.69, -0.15) x 10^20 cm^-2, consistent with the Galactic value of 3.4 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 3.7 x 10^-11 (4.0 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.55 (+3.69, -0.15) x 10^20 cm^-2 Galactic foreground: 3.4 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.78 (+0.16, -0.10) If the light curve continues to decay with a power-law decay index of 1.22, the count rate at T+24 hours will be 4.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x 10^-13 (1.8 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at https://www.swift.ac.uk/xrt_products/01430212. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/43320. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41410] GRB 260104A: Enhanced Swift-XRT position
by GCN Circulars 04 Jan '26

04 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43319 SUBJECT: GRB 260104A: Enhanced Swift-XRT position DATE: 26/01/04 14:49:33 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 3264 s of XRT Photon Counting mode data and 6 UVOT images for GRB 260104A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 337.39920, -21.29552 which is equivalent to: RA (J2000): 22h 29m 35.81s Dec (J2000): -21d 17' 43.9" with an uncertainty of 2.0 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at https://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/43319. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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