Phi

Its story

Phi Ophiuchi is a yellow-gold giant of the Serpent-Bearer, type G8, about three solar masses and thirteen solar radii. Only 360 million years old, it has already exhausted the hydrogen in its core: a 2018 Bayesian analysis gives a 94% chance it now burns helium on the red clump. At 244 light-years, it is moving toward us at 33 km per second.