Solar Flare Classification System
A
A-Class Flares
Peak flux: < 10⁻⁷ W/m²
Too weak to affect Earth
B
B-Class Flares
Peak flux: 10⁻⁷ - 10⁻⁶ W/m²
Minimal impact
C
C-Class Flares
Peak flux: 10⁻⁶ - 10⁻⁵ W/m²
Small flares, few noticeable effects
M
M-Class Flares
Peak flux: 10⁻⁵ - 10⁻⁴ W/m²
Medium-sized, can cause brief radio blackouts
X
X-Class Flares
Peak flux: ≥ 10⁻⁴ W/m²
Major flares - Nov 11, 2025: X5.1
Can cause planet-wide radio blackouts, radiation storms