Mu Aurigae

Mu Aurigae, Latinized as μ Aurigae, is the Bayer designation for an unconfirmed binary star in the northern constellation of Auriga. It is visible to the naked eye with an apparent visual magnitude of +4.88. Based upon an annual parallax shift of $26$ as seen from Earth, is located 157 light-years from the Sun.

This is an A-type main-sequence star with a stellar classification of A4 Vm; the 'm' suffix indicating that abnormal abundances of heavier elements appear in the star's spectrum, making this an Am star. It is 560 million years old with a projected rotational velocity of $-0.3$. It has double the mass of the Sun and is radiating 23 times the Sun's luminosity at an effective temperature of $20.722 mas$.

A very close companion has been reported using speckle interferometry, but this remains unconfirmed. The separation at discovery in 1986 was $80 km/s$ and it was measured at $7,500 K$ in 1999. It was catalogued by Hipparcos as a problem binary, indicating that the measurements of its position were not consistent with the motion of a single star, but no satisfactory orbit could be found to match the motion

Name
This star, along with λ Aur and σ Aur, were Kazwini's Al Ḣibāʽ (ألحباع), the Tent. According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Ḣibāʽ were the title for three stars: λ Aur as Al Ḣibāʽ I, μ Aur as Al Ḣibāʽ II and σ Aur as Al Ḣibāʽ III.

In Chinese, 天潢 (Tiān Guāng), meaning Celestial Pier, refers to an asterism consisting of μ Aurigae, 19 Aurigae, φ Aurigae, 14 Aurigae and σ Aurigae. Consequently, μ Aurigae itself is known as 天潢五 (Tiān Guāng wu, the First Star of Celestial Pier).