GRB 261010A: Swift and Fermi GBM detect a long-duration gamma-ray burst with complex emission profile.

AI Summary

GRB 261010A was detected by both Swift BAT and Fermi GBM, showing a main pulse followed by weaker emissions over 71.5 seconds. Swift-XRT refined the position to RA 16h 35m 04.2s, Dec +26d 36' 01.3", while optical follow-up searches yielded inconclusive results.

Measurements

Notices (1)

Fermi GBM — GRB · Sat, 10 Oct 2026 19:17:03 GMT

GCN Circulars (8)

GCN-45918 — GRB 261010A · Mon, 12 Oct 2026 04:10:48 GMT
The Swift-BAT team has refined the analysis of GRB 261010A, determining its position at RA 16h 35m 04.2s, Dec +26d 36' 01.3" with a duration of 71.5 seconds and a power-law index of 1.43. The event includes a main pulse and additional weak emissions, with a fluence of 3.1 x 10^-6 erg/cm2 in the 15-150 keV band.

GCN-45912 — GRB 261010A · Sun, 11 Oct 2026 22:16:41 GMT
The optical afterglow candidate for GRB 261010A was not detected in follow-up observations with the Nordic Optical Telescope, despite the refined Swift/XRT position confirming the candidate's location. The afterglow is located near the galaxy LEDA 1781464 at a redshift of 0.070, with a low probability of chance association.

GCN-45911 — GRB 261010A · Sun, 11 Oct 2026 21:47:48 GMT
On October 10, 2026, the Fermi Gamma-ray Burst Monitor (GBM) detected a gamma-ray burst (GRB 261010A) which was also observed by the Swift BAT. The event lasted approximately 54 seconds and had a peak photon flux of 8.2 ph/s/cm2, with a spectral analysis indicating a power law index of -1.30 and a cutoff energy of 450 keV.

GCN-45894 — GRB 261010A · Sun, 11 Oct 2026 10:24:10 GMT
The Swift-XRT team has reported an enhanced X-ray position for the gamma-ray burst GRB 261010A, with coordinates RA (J2000): 16h 34m 59.53s and Dec (J2000): +26d 34' 55.8

GCN-45891 — GRB 261010A · Sat, 10 Oct 2026 21:42:39 GMT
A possible optical afterglow of GRB 261010A was detected using the 1.5m telescope at Sierra Nevada Observatory, with a preliminary magnitude of I = 21.0 mag. The object was found slightly outside the Swift/XRT error circle, near a galaxy visible in archival plates, and further observations are needed to confirm its association with the gamma-ray burst.

GCN-45890 — GRB 261010A · Sat, 10 Oct 2026 21:39:17 GMT
Observations of the gamma-ray burst GRB 261010A using the Nordic Optical Telescope detected a new source, but its association with the GRB is tentative due to a 7" offset from the Swift/XRT position. Further observations are needed to confirm the relationship.

GCN-45889 — GRB 261010A · Sat, 10 Oct 2026 19:34:53 GMT
The Swift Burst Alert Telescope (BAT) detected a gamma-ray burst, GRB 261010A, at 19:17:07 UT on 26/10/10. The burst had a single-peaked structure lasting at least 5 seconds and a peak count rate of ~7000 counts/sec, with additional pulse structures possibly due to the burst or background noise.

GCN-45888 — GRB 261010A · Sat, 10 Oct 2026 19:27:41 GMT
The Fermi Gamma-ray Burst Monitor (GBM) detected a likely long Gamma-Ray Burst (GRB) designated GRB 261010A on 10 October 2026 at 19:17:03 UT. The event was located at RA = 244.7, Dec = 27.6 with a statistical uncertainty of 3.3 degrees, and additional data including a skymap and light curve are available for further analysis.