Gamma Geminorum (γ Gem, γ Geminorum) is the second brightest star in the constellation Gemini. It has the traditional names Alhena and Almeisan. This star 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 Earth.[1]

Excerpt from Wikipedia.