Petersen Diagram · Two Tones, One Star
unseel.com · P₁/P₀ vs P₀ · double-mode pulsators
P₁/P₀
f₁/f₀ ≈ 1.34
Stage
Fundamental (P₀, no node)
First overtone (P₁, 1 node)
Metal-poor ribbon (high ratio)
Metal-rich ribbon (low ratio)
Unseel.com · Petersen Diagram