Tau-4

Its story

Tau-4 Eridani follows the long course of the celestial river, a stream that meanders from the foot of Orion down into the southern skies. A red type M giant some 305 light-years away, its coppery light pulses with discreet variations that hint at a swelling atmosphere. It is one of many links in the chain of tau stars that articulate the current of Eridanus, the river that ancient cultures identified with the Po, the Nile, or the Euphrates depending on who looked up.