Zeta Reticuli is a binary star system that lies about 39 light years from Earth in the constellation Reticulum; it is just visible to the unaided eye under very dark skies. Zeta¹ Ret and Zeta² Ret are both yellow dwarf (main sequence) stars similar to the Sun but older, with an age of as much as 8 billion years old. Zeta¹ is slightly less massive and luminous than the Sun; Zeta² is very similar to the Sun in both mass and luminosity. The two stars revolve around each other with an orbital period of at least one million years at a mean distance of 9,000 astronomical units (AU). They belong to the Zeta Herculis stellar moving group.