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[vsnet-grb-info 40955] GRB 251129A: Optical Observations via Virtual Telescope Project, Italy
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42885 SUBJECT: GRB 251129A: Optical Observations via Virtual Telescope Project, Italy DATE: 25/11/29 05:27:43 GMT FROM: Gianluca Masi at Virtual Telescope Project <gianluca(a)bellatrixobservatory.org> Gianluca Masi, Virtual Telescope Project (Italy), reports: We attempted to observe the optical counterpart of GRB 251129A (Wenjun et al., GCN 42877) with the 14” robotic unit available at the Virtual Telescope Project facility in Manciano, Italy, equipped with a KAF-3200E based CCD camera, its QE peaking (90%) in the red part of the spectrum. We collected five, 300-second unfiltered exposures, then we averaged them. The central time of the resulting stack was 29 Nov., 04:54:23 UTC, that is about 2.4 hours after the burst. We detected a bright object at the following position (J2000.0): R.A.: 14 57 18.81 Decl.: +79 17 34.6 mean residuals < 0.1” on both axes R= 19.5 (assuming R-mags from Gaia DR2 for the reference stars). This position is consistent with Angulo et al. (GCN 42880). The source is not present in the PanSTARRS DR1 dataset. View this GCN Circular online at https://gcn.nasa.gov/circulars/42885. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40954] EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42884 SUBJECT: EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient DATE: 25/11/29 05:21:00 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y. Wu, Y. H. Jiang, C. Y. Dai (NJU), Y. Wang (PMO), H. C. Ding, T. Wu (AHNU), W. J. Zhang, Y. Liu (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 EP251129a. The transient triggered EP-WXT (ID: 01709248891) at 2025-11-29T03:14:23 (UTC). The WXT position of the source is R.A. = 224.294 deg, DEC = 79.301 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. = 224.3331 deg, DEC = 79.2903 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic). The position of FXT is 36 arcsec from SVOM/MXT detection of GRB 251129A (Tan et al., GCN 42877), and 10 arcsec from its optical counterpart (Angulo et al., GCN 42883). 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/42884. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40953] EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42884 SUBJECT: EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient DATE: 25/11/29 05:21:00 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y. Wu, Y. H. Jiang, C. Y. Dai (NJU), Y. Wang (PMO), H. C. Ding, T. Wu (AHNU), W. J. Zhang, Y. Liu (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 EP251129a. The transient triggered EP-WXT (ID: 01709248891) at 2025-11-29T03:14:23 (UTC). The WXT position of the source is R.A. = 224.294 deg, DEC = 79.301 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. = 224.3331 deg, DEC = 79.2903 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic). The position of FXT is 36 arcsec from SVOM/MXT detection of GRB 251129A (Tan et al., GCN 42877), and 10 arcsec from its optical counterpart (Angulo et al., GCN 42883). 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/42884. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40952] GRB 251129A: Correction to the position of the optical counterpar
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42883 SUBJECT: GRB 251129A: Correction to the position of the optical counterpar DATE: 25/11/29 04:48:59 GMT FROM: Alan Watson at UNAM <alan(a)astro.unam.mx> Alan Watson (UNAM) reports: The position of the optical counterpart given by Angulo et al. (GCN 42880) was not given completely correctly. The position was given correctly in sexagesimal but not in degrees. The correct position is: RA(J2000) = 14:57:18.88 = 224.3286 degrees Dec(J2000) = +79:17:34.8 = 79.2930 degrees We apologize for this error. We thank Huali Li for bringing this mistake to our attention. View this GCN Circular online at https://gcn.nasa.gov/circulars/42883. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40951] GRB 251129A: SVOM/VT optical counterpart confirmation with VHF data
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42882 SUBJECT: GRB 251129A: SVOM/VT optical counterpart confirmation with VHF data DATE: 25/11/29 04:12:26 GMT FROM: Huali Li at at NAOC, SVOM <lhl(a)nao.cas.cn> C. Wu, H. L. Li, L.P. Xin, Y. L. Qiu (NAOC), J. T. Palmerio (CEA), W. J. Tan (IHEP), D. F. Kong (GXU) report on behalf of the SVOM team. After the trigger by SVOM/ECLAIRs at 2025-11-29T02:32:05 UTC (T0), SVOM/VT performed an automatic slew to the burst GRB 251129A (sb25112901, Tan et al., GCN 42879). The observation began at 2025-11-29T02:43:03, 658 seconds after T0, in the VT_B (400nm-650nm) and VT_R (650nm-1000nm) channels simultaneously. The optical counterpart reported (Angulo et al., GCN 42880) was clearly detected in the 1-bit subimages and source lists downloaded via VHF network in both channels. The magnitudes are : Mid_time Band Magnitude (AB) 808 sec VT_B 18.63+/-0.01 mag 808 sec VT_R 18.02+/-0.01 mag Our photometry was derived in AB magnitude and not corrected for Galactic extinction. Given the VT color, it is likely a low redshift GRB. 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/VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS. View this GCN Circular online at https://gcn.nasa.gov/circulars/42882. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40950] GRB 251128A: Fermi GBM Observation
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42881 SUBJECT: GRB 251128A: Fermi GBM Observation DATE: 25/11/29 03:48:05 GMT FROM: rhamburg(a)usra.edu R. Hamburg (USRA), M. Godwin (UAH), Padraig McDermott (UCD), and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 04:22:21.61 UT on 28 November 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251128A (trigger 785996546/251128182; GCN 42865), which was also detected by Swift/BAT-GUANO (DeLaunay et al. 2025, GCN 42874). The angle from the Fermi LAT boresight is 114 degrees. The GBM light curve consists of multiple peaks with a duration (T90) of about 47 s (50-300 keV). The time-averaged spectrum from T0-0.0 to T0+44 s is best fit by a Band function with Epeak = 124 +/- 2, alpha = -0.92 +/- 0.01, and beta = -2.0 +/- 0.03. The event fluence (10-1000 keV) in this time interval is (1.95 +/- 0.13)e-05 ergs/cm^2. The 1-sec peak photon flux measured starting from T0+9.1 s in the 10-1000 keV band is 11.8 +/- 0.5 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/" View this GCN Circular online at https://gcn.nasa.gov/circulars/42881. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40949] GRB 251129A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42880 SUBJECT: GRB 251129A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate DATE: 25/11/29 03:38:10 GMT FROM: Camila Angulo Valdez at UNAM <camiangulo(a)astro.unam.mx> Camila Angulo (UNAM), Nikos Mandarakas (LAM), Alan M. Watson (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Jean-Luc Atteia (IRAP), Dalya Akl (NYUAD), 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), Noémie Globus (UNAM), Kin Ocelotl López (UNAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Enrique Moreno Méndez (UNAM), Margarita Pereyra (UNAM), N. A. Rakotondrainibe (LAM), Fredd Sánchez Álvarez (UNAM), Benjamin Schneider (LAM), Antonio de Ugarte Postigo (LAM), Wenjun Tan (IHEP), Defeng Kong (GXU), Wenjin Xie (NAOC), Donghua Zhao (NAOC), Hatsune Goto (Kanazawa Univ.) report: We imaged the field of the SVOM GRB 251129A (Tan et al., GCN Circ. 42877) using the DDRAGO two-channel wide-field imager on the SVOM/COLIBRÍ (FM-GFT) telescope. We observed from 2025-11-29 02:51:22 to 02:57:11 UTC (from 20.0 to 25.8 minutes after the trigger) and obtained 5 minutes of simultaneous exposure in the r and z filters. The data were reduced, coadded, and analyzed with the 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. We detect an uncatalogued source just outside the MXT error circle at: RA(J2000) = 14:57:18.88 = 224.2949 degrees Dec(J2000) = +79:17:34.8= 79.3050 degrees with an uncertainty of 0.5 arcsec. The preliminary magnitude derived for that source is: r = 18.30 +/- 0.01 z = 18.03 +/- 0.01 Further observations are ongoing. 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/42880. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40948] GRB 251129A: SVOM detection of a burst
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42879 SUBJECT: GRB 251129A: SVOM detection of a burst DATE: 25/11/29 03:15:27 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> Wenjun Tan (IHEP), Defeng Kong (GXU), Wenjin Xie, Donghua Zhao (NAOC), Hatsune Goto (Kanazawa Univ.) report on behalf of the SVOM mission team: At 2025-11-29T02:32:05 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 251129A (SVOM burst-id sb25112901). The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network. The burst was only detected by the Image Trigger (IMT), which produced a sequence of 5 alerts. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 8.82 in the [8-50] keV energy band over a time window of 81.92 seconds starting at 2025-11-29T02:31:24. The localization of the best alert is R.A., Dec. 224.5380, 79.4287 degrees (J2000) with a 90% confidence level (C.L.) radius of 8.96 arcmin (including systematic error of 2 arcmin added in quadrature). SVOM slewed to the burst. SVOM/MXT began observing the field at 2025-11-29T02:45:53 UTC, 828 seconds after T0. Using onboard processed data we found an uncatalogued X-ray source located at R.A., Dec. 224.3258, 79.3004 degrees: R.A. (J2000) = 14h57m01.94s Dec. (J2000) = 79d18m32.94s with a 90% C.L. radius of 25.08 arcseconds. This location is 7.82 arcminutes from the ECLAIRs onboard position. This position may be improved as more data is received. 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 Wenjun Tan: tanwj(a)ihep.ac.cn Please contact the BA by email if you require additional information. View this GCN Circular online at https://gcn.nasa.gov/circulars/42879. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40947] SVOM GRB251129.11: Global MASTER-Net observations report
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42878 SUBJECT: SVOM GRB251129.11: Global MASTER-Net observations report DATE: 25/11/29 03:14:31 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 GRB251129.11 (trigger No 1764383485,14h 58m 09.12s , +79d 25m 43.3s, R=0.1493) errorbox 9 sec after notice time and 997 sec after trigger time at 2025-11-29 02:48:01 UT, with upper limit up to 18.9 mag. Observations started at twilight. The observations began at zenith distance = 45 deg. The sun altitude is -16.3 deg. The galactic latitude b = 36 deg., longitude l = 116 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3054567 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 1057 | 2025-11-29 02:48:01 | MASTER-Kislovodsk | (14h 59m 33.58s , +79d 37m 30.3s) | C | 120 | 18.3 | 1177 | 2025-11-29 02:48:01 | MASTER-Kislovodsk | (14h 59m 33.58s , +79d 37m 30.3s) | C | 360 | 18.9 | Coadd 1057 | 2025-11-29 02:48:01 | MASTER-Kislovodsk | (15h 21m 37.07s , +79d 09m 16.3s) | C | 120 | 18.4 | 1197 | 2025-11-29 02:50:21 | MASTER-Kislovodsk | (14h 59m 33.13s , +79d 37m 36.2s) | C | 120 | 18.0 | 1197 | 2025-11-29 02:50:21 | MASTER-Kislovodsk | (15h 21m 37.81s , +79d 09m 22.5s) | C | 120 | 18.2 | 1337 | 2025-11-29 02:52:41 | MASTER-Kislovodsk | (14h 59m 32.62s , +79d 37m 42.8s) | C | 120 | 18.0 | 1337 | 2025-11-29 02:52:41 | MASTER-Kislovodsk | (15h 21m 38.00s , +79d 09m 30.4s) | C | 120 | 18.0 | 1487 | 2025-11-29 02:55:11 | MASTER-Kislovodsk | (14h 59m 32.17s , +79d 37m 50.0s) | C | 120 | 17.8 | 1607 | 2025-11-29 02:55:11 | MASTER-Kislovodsk | (14h 59m 32.18s , +79d 37m 50.0s) | C | 360 | 18.3 | Coadd 1487 | 2025-11-29 02:55:11 | MASTER-Kislovodsk | (15h 21m 37.94s , +79d 09m 39.5s) | C | 120 | 18.0 | 1627 | 2025-11-29 02:57:31 | MASTER-Kislovodsk | (14h 59m 31.42s , +79d 37m 57.4s) | C | 120 | 17.6 | 1627 | 2025-11-29 02:57:31 | MASTER-Kislovodsk | (15h 21m 37.84s , +79d 09m 49.2s) | C | 120 | 17.7 | 1766 | 2025-11-29 02:59:50 | MASTER-Kislovodsk | (14h 59m 30.65s , +79d 38m 04.2s) | C | 120 | 17.5 | 1766 | 2025-11-29 02:59:50 | MASTER-Kislovodsk | (15h 21m 37.58s , +79d 09m 57.9s) | C | 120 | 17.8 | 1906 | 2025-11-29 03:02:10 | MASTER-Kislovodsk | (14h 59m 29.69s , +79d 38m 11.3s) | C | 120 | 17.6 | 1906 | 2025-11-29 03:02:10 | MASTER-Kislovodsk | (15h 21m 37.28s , +79d 10m 06.9s) | C | 120 | 17.9 | 2046 | 2025-11-29 03:04:31 | MASTER-Kislovodsk | (14h 59m 28.84s , +79d 38m 19.5s) | C | 120 | 17.7 | 2046 | 2025-11-29 03:04:31 | MASTER-Kislovodsk | (15h 21m 37.01s , +79d 10m 17.3s) | C | 120 | 17.9 | 2186 | 2025-11-29 03:06:50 | MASTER-Kislovodsk | (14h 59m 27.87s , +79d 38m 27.5s) | C | 120 | 17.7 | 2186 | 2025-11-29 03:06:50 | MASTER-Kislovodsk | (15h 21m 36.63s , +79d 10m 27.4s) | C | 120 | 17.9 | 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/42878. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 40946] GRB 251129A: SVOM detection of a burst
by GCN Circulars 28 Nov '25

28 Nov '25

TITLE: GCN CIRCULAR NUMBER: 42877 SUBJECT: GRB 251129A: SVOM detection of a burst DATE: 25/11/29 03:14:08 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> Wenjun Tan (IHEP), Defeng Kong (GXU), Wenjin Xie, Donghua Zhao (NAOC), Hatsune Goto (Kanazawa univ.) report on behalf of the SVOM mission team: At 2025-11-29T02:32:05 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 251129A (SVOM burst-id sb25112901). The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network. The burst was only detected by the Image Trigger (IMT), which produced a sequence of 5 alerts. IMT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 8.82 in the [8-50] keV energy band over a time window of 81.92 seconds starting at 2025-11-29T02:31:24. The localization of the best alert is R.A., Dec. 224.5380, 79.4287 degrees (J2000) with a 90% confidence level (C.L.) radius of 8.96 arcmin (including systematic error of 2 arcmin added in quadrature). SVOM slewed to the burst. SVOM/MXT began observing the field at 2025-11-29T02:45:53 UTC, 828 seconds after T0. Using onboard processed data we found an uncatalogued X-ray source located at R.A., Dec. 224.3258, 79.3004 degrees: R.A. (J2000) = 14h57m01.94s Dec. (J2000) = 79d18m32.94s with a 90% C.L. radius of 25.08 arcseconds. This location is 7.82 arcminutes from the ECLAIRs onboard position. This position may be improved as more data is received. 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 Wenjun Tan: tanwj(a)ihep.ac.cn Please contact the BA by email if you require additional information. View this GCN Circular online at https://gcn.nasa.gov/circulars/42877. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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