It has an apparent visual magnitude of 1.9,[2] making it easily visible to the naked eye even in urban regions.

Based upon parallax measurements with the Hipparcos satellite, it is located at a distance of roughly 109 light-years (33 parsecs) from the Sun.

It is radiating around 123[9] times the luminosity of the Sun from its outer envelope at an effective temperature of 9,260 K.[10] This gives it a white hue typical of an A-class star.

[15] Alhena is a spectroscopic binary system with a period of 12.6 years (4,614.51 days) in a highly eccentric Keplerian orbit.

[22] Alhena was the name of a Dutch ship that rescued many people from an Italian cruise liner, the SS Principessa Mafalda, in October 1927.