GRB 260718A detected by Fermi GBM and SVOM/ECLAIRs with follow-up observations revealing potential X-ray counterpart

AI Summary

GRB 260718A was detected by Fermi GBM and SVOM/ECLAIRs, showing a 19-second emission episode with a peak photon flux of 2.1 ph/s/cm^2. Follow-up X-ray observations by the Einstein Probe (EP) identified an uncatalogued source within the error circle.

Measurements

Notices (1)

Fermi GBM — GRB · Sat, 18 Jul 2026 11:16:35 GMT

GCN Circulars (8)

GCN-45187 — GRB 260718A · Sun, 19 Jul 2026 02:45:20 GMT
The Einstein Probe (EP) performed a follow-up observation of the gamma-ray burst GRB 260718A, initially detected by SVOM/ECLAIRs and Fermi-GBM, identifying an uncatalogued X-ray source within the error circle. The observation, conducted 53 minutes post-trigger, revealed an average unabsorbed flux of 2.16 x 10^(-12) erg/s/cm^2 in the 0.5-10 keV energy band.

GCN-45185 — GRB 260718A · Sat, 18 Jul 2026 20:46:39 GMT
The MASTER-SAAO robotic telescope in South Africa began observing the Fermi GRB 260718A error box approximately 30,000 seconds after the trigger time, with an upper limit magnitude of 16.1. The observations were conducted under specific galactic coordinates and atmospheric conditions, and no optical transient was detected during the initial observations.

GCN-45184 — GRB 260718A · Sat, 18 Jul 2026 19:44:16 GMT
The SVOM mission team observed the field of GRB 260718A using the LCO 1m telescope at Siding Spring Observatory, starting about 7.3 hours after the initial detection. No uncatalogued source was identified in the ECLAIRs localisation region, and an upper limit magnitude of 20.1 (AB) in the PanSTARRS z filter was measured.

GCN-45181 — GRB 260718A · Sat, 18 Jul 2026 17:24:01 GMT
On July 18, 2026, the Fermi Gamma-ray Burst Monitor (GBM) detected GRB 260718A, a gamma-ray burst also observed by SVOM/ECLAIRs. The event lasted approximately 19 seconds and had a peak photon flux of 2.1 ph/s/cm^2 in the 10-1000 keV band.

GCN-45180 — GRB 260718A · Sat, 18 Jul 2026 17:08:36 GMT
The GRANDMA and KNC networks observed the field of GRB 260718A detected by SVOM/ECLAIRs but did not detect any optical counterpart. The upper limits reported are consistent with previous SVOM/VT observations.

GCN-45179 — GRB 260718A · Sat, 18 Jul 2026 16:56:45 GMT
The SVOM/VT telescope conducted observations of the gamma-ray burst GRB 260718A, starting approximately 44 minutes after the initial detection by SVOM/ECLAIRs. No credible optical sources were detected within the error box, with upper limits of AB magnitudes set at >23.2 mag for the VT_B band and >23.0 mag for the VT_R band.

GCN-45178 — GRB 260718A · Sat, 18 Jul 2026 14:52:36 GMT
The SVOM/VT telescope did not detect any optical source at the position of GRB 260718A, with upper limits of >21.5 mag in both VT_B and VT_R bands, suggesting the need for deeper or redder follow-ups to investigate the nature of the burst.

GCN-45177 — GRB 260718A · Sat, 18 Jul 2026 11:57:28 GMT
The Space-based multi-band astronomical Variable Objects Monitor (SVOM) detected a gamma-ray burst, GRB 260718A, on July 18, 2026, at 11:16:34 UTC. The burst was localized with a 90% confidence level radius of 4.20 arcmin and had a signal-to-noise ratio of 20.86 in the 5-20 keV energy band.