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GRB 260918A detected with multiple peaks and refined localization
AI Summary
GRB 260918A was detected by SVOM/ECLAIRs with a duration of 82 seconds and multiple peak lightcurve. Follow-up observations by Fermi/GBM and Einstein Probe (EP) identified transient X-ray sources, while optical searches yielded upper limits consistent with no new sources.
Measurements
| Event | GRB 260918A |
|---|---|
| Event ID | sb26091801 |
| Source | SVOM |
| Alert type | GRB |
| Significance | high |
| Trigger time (UTC) | Fri, 18 Sep 2026 03:47:15 GMT |
| Right ascension (J2000) | 354.725° |
| Declination (J2000) | -8.909° |
| Position error radius | 0.14550000000000002° (8.7′) |
| Position from | SVOM-ECLAIRs position, GCN 45692 |
| GCN notices | 1 |
| GCN circulars | 8 |
Every localisation reported in Circulars (1)
| Instrument | Of | Error | Circular |
|---|---|---|---|
| SVOM-ECLAIRs | burst | 8.7′ (90%) | GCN 45692 |
Observations (11)
Values parsed from the Circular text; each row names its Circular.
| Time since trigger | Band | Value | Telescope | Circular |
|---|---|---|---|---|
| T+9 min | VT_B | > 22.2 AB mag (limit) | SVOM/VT | GCN 45634 |
| T+9 min | VT_R | > 22.1 AB mag (limit) | SVOM/VT | GCN 45634 |
| T+18 min | r | > 22.1 AB mag (limit) | LCO 1m | GCN 45622 |
| T+26 min | z | > 20.3 AB mag (limit) | LCO 1m | GCN 45622 |
| T+91 min | VT_B | > 23.1 AB mag (limit) | SVOM/VT | GCN 45634 |
| T+91 min | VT_R | > 23 AB mag (limit) | SVOM/VT | GCN 45634 |
| T+3.0 h | r | > 23.46 AB mag (limit) | SVOM/COLIBRÍ (FM-GFT) | GCN 45620 |
| T+3.0 h | z | > 22.47 AB mag (limit) | SVOM/COLIBRÍ (FM-GFT) | GCN 45620 |
| T+12.3 h | r | > 21.1 AB mag (limit) | SVOM/C-GFT | GCN 45641 |
| T+12.4 h | g | > 20.5 AB mag (limit) | SVOM/C-GFT | GCN 45641 |
| T+12.7 h | i | > 20.5 AB mag (limit) | SVOM/C-GFT | GCN 45641 |
Notices (1)
SVOM — GRB · Fri, 18 Sep 2026 03:47:15 GMT
GCN Circulars (8)
GCN-45692 — GRB 260918A
· Tue, 22 Sep 2026 15:23:07 GMT
The SVOM/ECLAIRs team reported a refined analysis of GRB 260918A, a gamma-ray burst detected on September 18, 2026, with a multiple peak lightcurve and a duration of 82 seconds. The burst was also detected by Fermi/GBM and has a refined localization with a 90% confidence level radius of 8.73 arcmin.
GCN-45641 — GRB 260918A
· Sat, 19 Sep 2026 08:55:02 GMT
The SVOM/C-GFT team reported optical upper limits for GRB 260918A, with no credible candidate detected in g, r, and i bands. The non-detection is consistent with previous observations, and known optical sources were identified in specific positions.
GCN-45639 — GRB 260918A
· Fri, 18 Sep 2026 19:07:04 GMT
nap
GCN-45634 — GRB 260918A
· Fri, 18 Sep 2026 15:27:31 GMT
nap
GCN-45632 — GRB 260918A
· Fri, 18 Sep 2026 13:55:36 GMT
The Einstein Probe (EP) team conducted a follow-up observation of the gamma-ray burst GRB 260918A, detecting four uncataloged sources within the error circle of the initial detection. The observation, starting approximately 2 hours after the initial trigger, identified sources with varying flux levels, contributing to the study of transient X-ray events.
GCN-45622 — GRB 260918A
· Fri, 18 Sep 2026 06:24:38 GMT
nap
GCN-45620 — GRB 260918A
· Fri, 18 Sep 2026 05:29:47 GMT
The SVOM/COLIBRÍ (FM-GFT) telescope observed the field of GRB 260918A but did not detect any new source at the ECLAIRs source position, setting optical upper limits of r > 23.46 and z > 22.47. Further observations are ongoing.
GCN-45619 — GRB 260918A
· Fri, 18 Sep 2026 04:30:49 GMT
nap
AI summary generated Thu, 29 Oct 2026 23:07:42 GMT.