16 Aurigae

16 Aurigae is a triple star system located 232 light years away from the Sun in the northern constellation of Auriga. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.547, and is located about 2/3 of the way from Capella toward Beta Tauri. It also lies in the midst of the Melotte 31 cluster, but is merely a line-of-sight interloper. The system has a relatively high proper motion, advancing across the celestial sphere at the rate of 0.166 arc seconds per annum, and is moving closer to the Earth with a heliocentric radial velocity of −28 km/s.

The primary component is a single-lined spectroscopic binary with an orbital period of 434.16 days and an eccentricity of 0.1189. The visible member is an aging K-type giant star with a stellar classification of K2.5 IIIb CN-0.5; sometimes just given as K3 III. The notation of the former class indicates weak lines of CN in the spectrum. This star is an estimated five billion years old with 1.30 times the mass of the Sun. As a consequence of exhausting the hydrogen at its core, it has expanded to 18.8 times the Sun's radius. The star is radiating 112 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,264 K.

A third component is an magnitude 10.6 star at an angular separation of $31.63$. It shows a common proper motion with the primary and thus is a likely third member of the system.