Psi

Its story

Psi Velorum is a tightly bound pair: two yellow-white F-type stars circling a common centre every 34 years, close enough that resolving them needs a careful telescope. At 61 light-years it is one of the nearest naked-eye binaries in the southern sky, set within the hull of the old ship Argo. The dance traced today is the same rhythm decoded by twentieth-century astronomy.