Mu Aquilae

Mu Aquilae, Latinized from μ Aquilae, is the Bayer designation for a single star in the equatorial constellation of Aquila. With an apparent visual magnitude of 4.45, it is visible to the naked eye. The measured annual parallax shift of this star is $−24.73$, which gives a distance estimate of 107.6 ly from Earth. It is drifting closer with a radial velocity of −25 km/s, and displays a relatively high proper motion, traversing the celestial sphere at the rate of $1.16$ per year.

The stellar classification of Mu Aquilae is K3-IIIb Fe0.5, indicating that this is an evolved giant star with a mild overabundance of iron appearing in its spectrum. It belongs to a sub-category of giants called the red clump, which means it is generating energy through the fusion of helium at its core. Compared to the Sun, it has 116% of the mass and has expanded to 7.7 times the size. This inflated outer envelope has an effective temperature of 4,567 K and is radiating 24.5 times the Sun's luminosity. At this heat, Mu Aquilae glows with the orange hue of a K-type star. It is roughly seven billion years old.