Caph

Its story

Caph, beta Cassiopeiae, anchors one tip of the northern W and trembles as a Delta Scuti variable, pulsing every two and a half hours. Her name comes from the Arabic «al-kaff», the palm of the hand: an ancient anatomical fragment transplanted into the medieval Arab inventory of the sky. At 54.8 light-years, she is one of the nearest neighbours that the eye can distinguish without effort on northern nights.