Eta Aurigae (η Aur, η Aurigae) is a star in the constellation Auriga. It has the traditional name Hoedus II or Haedus II. With an apparent visual magnitude of 3.18, it is visible to the naked eye. Based upon parallax measurements made during the Hipparcos mission, this star is approximately 243 light-years (75 parsecs) distant from the Earth.
Eta Aurigae is a larger star than the Sun, with more than five times the Sun's mass and over three times the Sun's radius. The spectrum of this star matches a stellar classification of B3 V, which is a B-type main sequence star that is generating its energy through the nuclear fusion of hydrogen at its core. It is radiating 955 times the Sun's luminosity from its outer atmosphere at an effective temperature of 17,201 K. Based upon its projected rotational velocity of 95, it is spinning with a rotation period of only 1.8 days. Eta Aurigae is around 39 million years old.
Read more about Eta Aurigae: Etymology