General information
GRB 251213A is a long-duration gamma-ray burst triggered around 2025-12-13 12:30:04–12:30:05 UTC and reported by multiple high-energy instruments. Reported durations are consistently T90 ≈ 35–39 s with a multi-pulsed prompt lightcurve.
Wavelength coverage
- Gamma-rays / hard X-rays (prompt): detected by GECAM-B, SVOM/GRM, GRID (10B/11B), and AstroSat CZTI (including CZT 20–200 keV and Veto 100–500 keV).
No observations were mentioned in: soft X-ray, UV, optical, near-IR, radio, TeV.
Lightcurve and spectrum
- Duration: T90 = 34.6 ± 2.8 s (GRID-11B; 30–2000 keV); T90 = 35.5 ± 3.2 s (GRID-10B; 30–2000 keV); T90 = 36.5 (+1.0/−1.0) s (SVOM/GRM; 15–5000 keV); T90 = 34.6 (+1.0/−1.0) s (GECAM-B; ~70–6000 keV); T90 = 39 (+1/−14) s (AstroSat CZTI; 20–200 keV); T90 = 36 (+1/−2) s (AstroSat Veto; 100–500 keV).
- Temporal structure: precursor followed by multiple pulses (GECAM-B); multiple pulses (SVOM/GRM).
- Spectrum (time-averaged, T0−5 to T0+45 s): cutoff power-law with index −0.95 (+0.10/−0.09) and Epeak = 453 (+63/−50) keV; fluence (10–1000 keV) = 5.58e-05 erg/cm^2 (SVOM/GRM).
- Spectrum (1 s peak, T0+5 to T0+6 s): cutoff power-law with index −1.09 (+0.14/−0.12) and Epeak = 800 (+286/−182) keV; flux (10–1000 keV) = 3.31e-06 erg/cm^2/s (SVOM/GRM).
Redshift
What’s special vs typical
- Reported as detected by several non-Fermi high-energy monitors (GECAM-B/SVOM/GRM/GRID/AstroSat), with an explicit note that non-detection by Fermi/GBM may help further constrain the error box.