Phi

Its story

Phi Aurigae is an orange-red giant with a radius thirty-five times the Sun's, an aged star whose surface breathes at barely 4,227 K. At 453 light-years inside the wide Charioteer, it also forms a visual double easily caught in binoculars. Its warm tone recalls glowing coal —the colour of a star no longer fusing hydrogen the way it did in its youth.