General information
GRB 260601A is a well-confirmed short GRB first reported by Fermi/GBM at 2026-06-01 11:00:12 UT near RA 15.06 deg, Dec 44.38 deg. It was later reported by multiple gamma-ray instruments and triangulated by the IPN.
Wavelength coverage
- Gamma-ray: Fermi/GBM, Glowbug, GECAM-B, SVOM/GRM, CALET/CGBM, Konus-Wind, and Avion reported detections with short durations and hard prompt spectra.
- Optical: MASTER-OAGH began observations 327 s after trigger and reported upper limits up to 19.5 mag, with no optical transient reported.
No radio, infrared, ultraviolet, X-ray, neutrino, or gravitational-wave observations are mentioned.
Lightcurve and spectrum
- Fermi/GBM reported a single emission episode with T90 about 0.8 s in 50-300 keV, cutoff-power-law index -0.63 +/- 0.02, Epeak 960 +/- 30 keV, fluence (2.08 +/- 0.06)e-6 erg/cm2 in 10-1000 keV, and 64-ms peak photon flux 40 +/- 1 ph/s/cm2.
- Glowbug reported onset at 2026-06-01 11:00:11.408, duration 0.26 s, about 77 sigma significance, and a triple-peaked structure.
- GECAM-B reported multi-pulse emission with T90 0.78 +0.21/-0.57 s in about 70-6000 keV.
- SVOM/GRM reported multi-pulse emission with T90 0.20 +0.47/-0.09 s in 15-5000 keV, cutoff-power-law index -1.04 +0.15/-0.17, Epeak 899 +210/-150 keV, and fluence (3.28 +0.138/-0.13)e-6 erg/cm2 in 10-1000 keV.
- CALET/CGBM reported a multi-peaked signal seen by all CGBM detectors, starting at T+0.40 s, peaking at T+0.50 s, ending at T+0.59 s, with T90 0.18 +/- 0.01 s and T50 0.05 +/- 0.03 s in 40-1000 keV.
- Konus-Wind reported a multipeaked light curve of about 0.2 s duration, emission up to about 2 MeV, fluence 3.05(-0.27,+0.29)e-6 erg/cm2, 16-ms peak flux 4.04(-0.53,+0.55)e-5 erg/cm2/s, alpha -0.44(-0.13,+0.14), and Ep 780(-91,+107) keV.
- Avion reported 43 photons in DeCoR-3 above 30 keV, fluence about 4e-7 erg/cm2 in 30-500 keV, a single episode of about 0.5 s, maximum flux about 10 phot/(cm2*s), and T90 less than about 0.5 s.
Redshift
What’s special vs typical
The burst is notable for broad prompt gamma-ray confirmation across many spacecraft and an IPN triangulation, with consistently short duration and hard spectral properties. The provided circulars do not report a counterpart or redshift, so its specialness is mainly in the richness of prompt high-energy coverage rather than a confirmed physical association.