At Epsilon Geminorum's distance,
extinction from interstellar dust is causing a magnitude reduction of 0.27. The
spectrum of this star matches a
stellar classification of G8 Ib, where the
luminosity class of Ib indicates this is a lower luminosity
supergiant star. Alternatively, it may be a star that has passed through the
asymptotic giant branch stage and possesses a detached shell of dust. It has 5.3 times the
mass of the Sun and it is estimated to be 100 million years old. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. The radius of Epsilon Geminorum has been directly measured using
interferometry with the
Navy Precision Optical Interferometer, which yields a result of 130 times the
radius of the Sun. It is radiating around 7,000 times the
luminosity of the Sun from its outer atmosphere at an
effective temperature of . It is this temperature that gives it the yellow-hued glow of a
G-type star. A surface
magnetic field with a strength of has been detected on this star. This topologically complex field is most likely generated by a dynamo formed from the deep
convection zone in the star's outer envelope. ==Occultations==