Psi4 Aurigae
Psi4 Aurigae is a single, orange-hued star in the northern constellation of Auriga. Its name is a Bayer designation that is Latinized from ψ4 Aurigae, and abbreviated Psi4 Aur or ψ4 Aur. This star is visible to the naked eye with an apparent visual magnitude of +5.02. With an annual parallax shift of, it is approximately distant from Earth. The star is drifting closer to the Sun with a radial velocity of −77 km/s, and may approach to within in around 1.1 million years.
This is a evolved K-type giant star with a stellar classification of K5 III, having exhausted the hydrogen at its core. With nearly the same mass as the Sun, it has expanded to 25 times the Sun's radius. The star is radiating 182 times the Sun's luminosity from its enlarged photosphere at an effective temperature of about 4,158 K. It is spinning with a projected rotational velocity of 4.8 km/s. This is an α–enhanced star, displaying a significant enhancement of silicon in its atmosphere.
Psi4 Aurigae was part of a much bigger constellation named Telescopium Herschelii before that asterism was no longer recognized by the International Astronomical Union.