General information
GRB 251208A is a likely short gamma-ray burst detected by multiple high-energy monitors (Fermi/GBM, SVOM/GRM, GECAM-B, Glowbug, and AstroSat/CZTI). The prompt emission is described as a single-peaked event occurring around 2025-12-08 09:25:56–58 UTC.
Wavelength coverage
- Gamma-rays: Detected by Fermi/GBM, SVOM/GRM, GECAM-B, and Glowbug with prompt timing and light-curve characterization.
- Hard X-rays: Faint detection reported in AstroSat/CZTI (20–200 keV) and a clear detection in CZTI veto (100–500 keV).
No observations are mentioned in soft X-ray, UV, optical, IR, or radio bands.
Lightcurve and spectrum
- Duration: T90 = 2.2 +0.9/-0.5 s (15–5000 keV; SVOM/GRM); T90 = 2.4 +0.7/-1.2 s (70–6000 keV; GECAM-B).
- Light-curve morphology: single pulse (SVOM/GRM; Glowbug).
- Spectrum (time-averaged, T0-1 to T0+2 s): cutoff power law with photon index -1.20 +0.19/-0.18 and Epeak = 135 +51/-27 keV (SVOM/GRM).
- Fluence: (1.29 +0.19/-0.14)×10^-6 erg/cm^2 (10–1000 keV; T0-1 to T0+2 s; SVOM/GRM).
- 1 s peak spectrum (T0-0.6 to T0+0.4 s): cutoff power law with photon index -0.98 +0.17/-0.18 and Epeak = 139 +33/-21 keV (SVOM/GRM).
- 1 s peak flux: (7.79 +0.91/-0.72)×10^-7 erg/cm^2/s (10–1000 keV; SVOM/GRM).
- Significance: ~13.5 sigma total significance reported by Glowbug.
Redshift
What’s special vs typical