Psi2 Aurigae

Psi2 Aurigae, Latinized from ψ2 Aurigae, is a star in the constellation Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 4.79. Based upon parallax measurements, this star is approximately 420 ly away from the Earth. At that distance, the brightness of the star is diminished by 0.07 in magnitude from extinction caused by interstellar gas and dust.

Most studies categorized this as a K-type giant star with a stellar classification of K3 III. However, the results of a study published in 2003 list it with a classification of K3 Iab:, which would instead suggest it is a supergiant star. The measured angular diameter of this star, after correction for limb darkening, is 1.97 ± 0.02 mas. At the estimated distance of this star, this yields a physical size of about 27 times the radius of the Sun. It is radiating 304 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,410 K.

It was also known to be part of a much bigger constellation named Telescopium Herschelii. It was also the constellation's second-brightest star before it was unrecognized by the International Astronomical Union (IAU).