GCN 45177: GRB 260718A: SVOM detection of a burst

2026-07-18T11:57:28.227Z | rev 0 | event: GRB 260718A
S. Antier (IJCLAB),  D. Zhao (NAOC), W. Zhang (PMO), Y. Ma (NAOC), C. Wang (IHEP) report on behalf of the SVOM mission team:

At 2026-07-18T11:16:34 UTC (T0), SVOM/ECLAIRs triggered and located the gamma-ray burst GRB 260718A (SVOM burst-id sb26071802).

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 19 alerts. CRT provided the alert with the best signal-to-noise-ratio in the image (SNR) of 20.86 in the [5-20] keV energy band over a time window of 20.40 seconds starting at 2026-07-18T11:16:31.

The localization of the best alert is R.A., Dec. 37.2660, -56.0993 degrees:
R.A. (J2000) = 2h29m03.85s
Dec. (J2000) = -56d05m57.31s
 with a 90% confidence level (C.L.) radius of 4.20 arcmin (including systematic error of 2 arcmin added in quadrature).

The SVOM/ECLAIRs light curve showed a broad peak structure.

This burst was also detected by SVOM/GRM. : https://www.bursthub.cn/gcn/2026/svgrb260718A.png

SVOM slewed to the burst. No immediate MXT and VT observation could be carried out due to Earth occultation. Later observations will be reported in future GCN Circulars.

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 Wenlong Zhang: wlzhang@pmo.ac.cn.
Please contact the BA by email if you require additional information.