Zeta Reticuli

Zeta Reticuli

Zeta Reticuli. Image: 15 × 15 arcminutes; north up, east left.
NASA Digital Sky Survey.

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.


visual magnitude 5.54 (Zeta1); 5.24 (Zeta2)
spectral type G2.5V (Zeta1); G1V (Zeta2)
distance 39.41 light-years
position R.A. 3h 17m 46.2s, Dec. -62° 34' 31.6" (Zeta1)
R.A. 3h 18m 12.8s, Dec. -62° 30' 22.9" (Zeta2)
other designations Gl 136, HD 20766, HR 1066,
HIP 15330, SAO 248770 (Zeta1)
Gl 138, HD 20807, HR 1010,
HIP 15371, SAO 248 774 (Zeta2)