Long GRB 260917A detected by Fermi GBM with ~8.5s duration, confirmed by Glowbug

AI Summary

Fermi GBM triggered on a long gamma-ray burst (GRB 260917A) at 2026-09-17 02:24:08 UT with a duration of approximately 8.5 seconds. The burst was localized to RA=310.2°, Dec=-31.9° with a statistical error radius of 1.4° and systematic error of ~1°. The detection was confirmed by the Glowbug gamma-ray telescope on the ISS, which observed the brightest initial peak. Ground-based optical follow-up by MASTER-OAFA robotic telescope began within 36-76 seconds of the trigger but detected no optical transient, with upper limits reaching magnitude 19.7-20.0.

Measurements

Every localisation reported in Circulars (1)

Observations (3)

Values parsed from the Circular text; each row names its Circular.

Notices (1)

Fermi GBM — GRB · Thu, 17 Sep 2026 02:24:08 GMT

GCN Circulars (5)

GCN-45613 — GRB 260917A · Thu, 17 Sep 2026 15:22:35 GMT
The Glowbug gamma-ray telescope on the International Space Station detected GRB 260917A, a gamma-ray burst that lasted approximately 8.5 seconds. This detection, confirmed by the Fermi/GBM, occurred during a period of high background radiation in the southern radiation belt, and the analysis is preliminary.

GCN-45609 — GRB260917 · Thu, 17 Sep 2026 08:57:44 GMT
The MASTER-OAFA robotic telescope in Argentina observed the error box of the gamma-ray burst SVOM GRB260917.16, starting 17,228 seconds after the trigger time, with upper limits up to 20.0 magnitude. No optical transient was detected in the clear filter band during the observations.

GCN-45604 — GRB 260917A · Thu, 17 Sep 2026 02:57:11 GMT
A gamma-ray burst, GRB 260917A, was detected by the Fermi Gamma-ray Burst Monitor on September 17, 2026. The BALROG algorithm localized the burst to a position with a right ascension of 310.2 degrees and a declination of -31.9 degrees, with an estimated error radius of 1.4 degrees (statistical) and 1 degree (systematic).

GCN-45603 — GRB 260917A · Thu, 17 Sep 2026 02:34:35 GMT
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GCN-45602 — GRB260917 · Thu, 17 Sep 2026 02:31:10 GMT
The MASTER-OAFA robotic telescope in Argentina began observing the Fermi GRB260917.10 event 36 seconds after the alert, with an upper magnitude limit of 19.7. The observation was conducted under specific celestial conditions, including a zenith distance of 10 degrees and a sun altitude of -48.4 degrees.