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

[vsnet-grb-info 41403] GRB 260101A: COLIBRÍ optical observations
by GCN Circulars 03 Jan '26

03 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43312 SUBJECT: GRB 260101A: COLIBRÍ optical observations DATE: 26/01/03 06:27:01 GMT FROM: globus(a)astro.unam.mx Noémie Globus (UNAM), Sarah Antier (IJCLAB), Alan M. Watson (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Jean-Luc Atteia (IRAP), Dalya Akl (NYUAD), 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), 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 observed the optical counterpart of the “New Year Burst”, GRB 260101A (Fermi GBM team, GCN Circ. 43284; Cenko et al., GCN Circ. 43285; Pérez-Fournon et al., GCN Circ. 43286; de Ugarte Postigo et al., GCN Circ. 43287; Beardmore et al., GCN Circ. 43289; Lipunov et al., GCN Circ. 43290; D'Avanzo et al., GCN Circ. 43291; SVOM/GRM team et al., GCN Circ. 43292; Saccardi et al., GCN Circ. 43293; Wang et al., GCN Circ. 43294; Hristov et al., GCN Circ. 43297) using the DDRAGO wide-field imager on the COLIBRÍ telescope. We observed from 2026-01-03 03:22 to 05:47 UTC (50.4 hours to 52.9 hours after the trigger) and obtained 105 minutes of simultaneous exposure in the r and z filters. The data were reduced and coadded with the COLIBRÍ ASU pipeline. The photometry was calibrated using nearby stars from the PanSTARRS DR1 catalog, is in the AB system, and is not corrected for Galactic extinction. In our stacked images, we detect a source at the position of the afterglow (Cenko et al., GCN Circ. 43285) at preliminary magnitudes of: r = 22.11 +/- 0.11, z = 21.47 +/- 0.09. 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/43312. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41402] SVOM GRB260103.08: Global MASTER-Net observations report
by GCN Circulars 03 Jan '26

03 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43311 SUBJECT: SVOM GRB260103.08: Global MASTER-Net observations report DATE: 26/01/03 02:28:23 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 SVOM GRB260103.08 (trigger No 1767405296,10h 29m 22.85s , +78d 07m 01.2s, R=1) errorbox 9 sec after notice time and 47 sec after trigger time at 2026-01-03 01:55:42 UT, with upper limit up to 17.8 mag. The observations began at zenith distance = 36 deg. The sun altitude is -29.5 deg. The galactic latitude b = 37 deg., longitude l = 131 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3094431 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 52 | 2026-01-03 01:55:42 | MASTER-Kislovodsk | (10h 28m 21.31s , +78d 15m 14.6s) | C | 10 | 16.1 | 72 | 2026-01-03 01:55:42 | MASTER-Kislovodsk | (10h 28m 21.31s , +78d 15m 14.7s) | C | 50 | 17.2 | Coadd 52 | 2026-01-03 01:55:43 | MASTER-Kislovodsk | (10h 26m 28.30s , +78d 37m 51.0s) | P| | 10 | 15.1 | 88 | 2026-01-03 01:56:13 | MASTER-Kislovodsk | (10h 28m 20.71s , +78d 15m 17.8s) | C | 20 | 16.5 | 88 | 2026-01-03 01:56:13 | MASTER-Kislovodsk | (10h 26m 27.38s , +78d 37m 54.9s) | P| | 20 | 15.8 | 129 | 2026-01-03 01:56:54 | MASTER-Kislovodsk | (10h 28m 20.20s , +78d 15m 20.4s) | C | 20 | 16.4 | 129 | 2026-01-03 01:56:54 | MASTER-Kislovodsk | (10h 26m 26.58s , +78d 37m 57.6s) | P| | 20 | 15.7 | 174 | 2026-01-03 01:57:35 | MASTER-Kislovodsk | (10h 28m 19.34s , +78d 15m 23.0s) | C | 30 | 16.8 | 219 | 2026-01-03 01:57:35 | MASTER-Kislovodsk | (10h 28m 19.30s , +78d 15m 23.2s) | C | 120 | 17.5 | Coadd 174 | 2026-01-03 01:57:35 | MASTER-Kislovodsk | (10h 26m 25.67s , +78d 38m 00.3s) | P| | 30 | 15.9 | 229 | 2026-01-03 01:58:25 | MASTER-Kislovodsk | (10h 28m 18.65s , +78d 15m 25.6s) | C | 40 | 16.8 | 229 | 2026-01-03 01:58:25 | MASTER-Kislovodsk | (10h 26m 24.60s , +78d 38m 02.7s) | P| | 40 | 16.1 | 295 | 2026-01-03 01:59:25 | MASTER-Kislovodsk | (10h 28m 17.63s , +78d 15m 28.0s) | C | 50 | 16.9 | 295 | 2026-01-03 01:59:25 | MASTER-Kislovodsk | (10h 26m 23.54s , +78d 38m 04.8s) | P| | 50 | 16.2 | 375 | 2026-01-03 02:00:35 | MASTER-Kislovodsk | (10h 28m 16.24s , +78d 15m 30.2s) | C | 70 | 17.1 | 475 | 2026-01-03 02:00:35 | MASTER-Kislovodsk | (10h 28m 16.19s , +78d 15m 30.3s) | C | 270 | 17.8 | Coadd 375 | 2026-01-03 02:00:35 | MASTER-Kislovodsk | (10h 26m 22.26s , +78d 38m 06.6s) | P| | 70 | 16.4 | 475 | 2026-01-03 02:02:05 | MASTER-Kislovodsk | (10h 28m 14.77s , +78d 15m 32.1s) | C | 90 | 17.2 | 475 | 2026-01-03 02:02:05 | MASTER-Kislovodsk | (10h 26m 20.59s , +78d 38m 07.9s) | P| | 90 | 16.6 | 596 | 2026-01-03 02:03:56 | MASTER-Kislovodsk | (10h 28m 13.42s , +78d 15m 32.8s) | C | 110 | 17.3 | 596 | 2026-01-03 02:03:56 | MASTER-Kislovodsk | (10h 26m 18.31s , +78d 38m 08.2s) | P| | 110 | 16.4 | 731 | 2026-01-03 02:06:07 | MASTER-Kislovodsk | (10h 28m 13.42s , +78d 15m 32.8s) | C | 120 | 14.8 | 731 | 2026-01-03 02:06:07 | MASTER-Kislovodsk | (10h 26m 18.35s , +78d 38m 07.2s) | P| | 120 | 14.4 | 908 | 2026-01-03 02:09:34 | MASTER-Kislovodsk | (10h 34m 57.99s , +79d 17m 59.5s) | C | 60 | 17.0 | 908 | 2026-01-03 02:09:34 | MASTER-Kislovodsk | (10h 09m 58.98s , +79d 35m 40.7s) | C | 60 | 17.2 | 1008 | 2026-01-03 02:11:13 | MASTER-Kislovodsk | (10h 50m 24.38s , +77d 23m 12.9s) | C | 60 | 17.0 | 1008 | 2026-01-03 02:11:13 | MASTER-Kislovodsk | (10h 29m 13.06s , +77d 41m 41.3s) | C | 60 | 17.3 | 1113 | 2026-01-03 02:12:58 | MASTER-Kislovodsk | (10h 29m 26.49s , +78d 16m 54.1s) | C | 60 | 17.0 | 1113 | 2026-01-03 02:12:58 | MASTER-Kislovodsk | (10h 06m 36.99s , +78d 34m 43.4s) | C | 60 | 17.2 | 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/43311. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41401] GRB 260102B: Fermi GBM Final Real-time Localization
by GCN Circulars 02 Jan '26

02 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43310 SUBJECT: GRB 260102B: Fermi GBM Final Real-time Localization DATE: 26/01/02 21:23:33 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 SHORT GRB At 21:12:03 UT on 2 Jan 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260102B (trigger 789081128.373244 / 260102883). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 60.7, Dec = -67.8 (J2000 degrees, equivalent to J2000 04h 02m, -67d 47'), with a statistical uncertainty of 17.7 degrees. The angle from the Fermi LAT boresight is 23.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260102883/… The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260102883/… The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260102883/… View this GCN Circular online at https://gcn.nasa.gov/circulars/43310. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41400] SVOM GRB260102.17: Global MASTER-Net observations report
by GCN Circulars 02 Jan '26

02 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43309 SUBJECT: SVOM GRB260102.17: Global MASTER-Net observations report DATE: 26/01/02 18:14:24 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 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/43309. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41399] Fermi GBM Sub-Threshold Detection of GRB 260102A
by GCN Circulars 02 Jan '26

02 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43308 SUBJECT: Fermi GBM Sub-Threshold Detection of GRB 260102A DATE: 26/01/02 17:59:21 GMT FROM: rhamburg(a)usra.edu 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 View this GCN Circular online at https://gcn.nasa.gov/circulars/43308. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41398] GRB 260102A: EP-FXT follow-up observation
by GCN Circulars 02 Jan '26

02 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43307 SUBJECT: GRB 260102A: EP-FXT follow-up observation DATE: 26/01/02 15:50:27 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> 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). View this GCN Circular online at https://gcn.nasa.gov/circulars/43307. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41397] EP260101a: Global MASTER-Net observations report
by GCN Circulars 02 Jan '26

02 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43306 SUBJECT: EP260101a: Global MASTER-Net observations report DATE: 26/01/02 15:18:21 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 EP260101a ( EP Team et al., GCN 43288) errorbox 1 days 27579 sec after notice time and 1 days 29347 sec after trigger time at 2026-01-02 14:44:49 UT, with upper limit up to 15.3 mag. Observations started at twilight. The observations began at zenith distance = 30 deg. The sun altitude is -10.3 deg. The galactic latitude b = -16 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=3092541 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 115778 | 2026-01-02 14:44:49 | MASTER-Kislovodsk | (03h 03m 11.45s , +39d 18m 40.8s) | C | 60 | 15.3 | 116532 | 2026-01-02 14:57:23 | MASTER-Kislovodsk | (03h 03m 11.69s , +39d 19m 18.4s) | C | 60 | 14.7 | 116631 | 2026-01-02 14:59:03 | MASTER-Kislovodsk | (03h 03m 05.44s , +39d 18m 20.6s) | C | 60 | 14.5 | 116730 | 2026-01-02 15:00:41 | MASTER-Kislovodsk | (03h 03m 10.27s , +39d 18m 43.9s) | C | 60 | 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/43306. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41396] GRB 260102A: LCO optical upper limits
by GCN Circulars 02 Jan '26

02 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43305 SUBJECT: GRB 260102A: LCO optical upper limits DATE: 26/01/02 15:02:54 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/43305. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41395] GRB 260102A: Swift-XRT observations
by GCN Circulars 02 Jan '26

02 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43304 SUBJECT: GRB 260102A: Swift-XRT observations DATE: 26/01/02 14:37:52 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/43304. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 41394] GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
by GCN Circulars 02 Jan '26

02 Jan '26

TITLE: GCN CIRCULAR NUMBER: 43303 SUBJECT: GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations DATE: 26/01/02 14:09:15 GMT FROM: Dalya Akl at New York University Abu Dhabi <dka2010(a)nyu.edu> 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/43303. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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