General information (1–2 sentences, single paragraph, no bullets)
EP251212a / GRB 251212A is a fast X-ray transient detected by Einstein Probe/WXT on 2025-12-12 06:12:52 UTC and subsequently detected in hard X-rays by AstroSat/CZTI. EP/FXT follow-up found an uncatalogued X-ray source within the WXT error circle, while optical follow-up reports only upper limits.
Wavelength coverage (bullets by band + final sentence listing bands with no observations mentioned)
- X-ray (soft): Einstein Probe/WXT detection with a ~100 s duration; Einstein Probe/FXT follow-up detection and spectrum/flux.
- X-ray / gamma-ray (hard): AstroSat/CZTI detection in 20–200 keV and 100–500 keV.
- Optical: COLIBRÍ (r,z) non-detection; KAIT (clear ~R) non-detection; MASTER-Net (clear) non-detections.
No observations were mentioned in radio, infrared, ultraviolet, or very-high-energy gamma rays.
Lightcurve and spectrum (ONLY items explicitly reported: T90/duration, flux/fluence, spectral model+params, temporal decay; if nothing, leave empty)
- Duration: WXT event lasted ~100 s (GCN 43076).
- T90: 5.6 (+0.6, -3.8) s (CZTI 20–200 keV) and 5.7 (+0.9, -1.9) s (CZTI Veto 100–500 keV) (GCN 43082).
- Spectral model (WXT): absorbed power law with NH = 3.6×10^21 cm^-2 and photon index = 1.1 (GCN 43076).
- Flux (WXT): average unabsorbed 0.5–4 keV flux ≈ 2.0×10^-9 erg s^-1 cm^-2 (GCN 43076).
- Spectral model (FXT): absorbed power law with NH = 1.1×10^21 cm^-2 and photon index = 1.7 (GCN 43081).
- Flux (FXT): unabsorbed 0.5–10 keV flux ≈ 1.54×10^-12 erg s^-1 cm^-2 (GCN 43081).
Redshift (1–3 bullets; only if redshift mentioned; else leave empty)
What’s special vs typical (ONLY if there is at least one clearly special/atypical aspect; do not mention absence of non-EM; if nothing special, leave empty)