Alpheratz

Its story

Alpheratz closes the chain of Andromeda and opens the Square of Pegasus, an astronomical hinge linking princess and winged horse. Its name, from the Arabic «al-faras», recalls that ancient double belonging. A blue-white B-class star, mildly variable and chemically peculiar, it carries unusual concentrations of mercury and manganese that betray strange atmospheric processes 97 light years from the Sun.