Gemini

Origin

Gemini is a northern hemisphere constellation cataloged by the second-century astronomer Ptolemy. Gemini is one of the constellations of the zodiac, since it lies on the apparent path the Sun takes across the sky. Gemini represents the twins Castor and Pollux in Greek mythology who have their models in the Babylonian uranology as the warriors Lugalirra and Meslamta’ea. Gemini is primarily a winter/spring constellation.

Bright Stars

Gemini is located in a rich part of the sky with many bright stars visible to the naked eye. Pollux (Beta Geminorum) is the brightest star, shining at magnitude 1.14. Pollux is an orange giant located 34 light-years from Earth. Castor (Alpha Geminorum) appears as a magnitude-1.6 blue-white star to the naked eye. Castor is a double star with two components, of magnitude 1.9 and 3.0, located 52 light-years from Earth. Castor is a good double star for small telescopes. Alhena, or Gamma Geminorum, is a blue-white star shining at magnitude 1.9 lying 105 light-years away. Epsilon Geminorum, known as Mebsuta, is a double star located 900 light-years from Earth. The primary star shines at magnitude 3.1 and the secondary star is magnitude 9.6 and can be seen in small telescopes.