Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Gamma Geminorum is the second brightest star in the constellation Gemini. It has the traditional names Alhena and Almeisan. In the catalogue of stars in the Calendarium of Al Achsasi Al Mouakket, this star was designated Nir al Henat, which was translated into Latin as Prima al Henat, meaning the brightest of Al Henat. Alhena is 105 light-years distant from Earth, and has an apparent magnitude of 1.93 and belongs to the spectral class A0. It is a spectroscopic binary with a faint class-G companion.