Castor, Alpha Geminorum (α Gem), is a sextuple star system located at a distance of 51 ly from Earth in the constellation Gemini. It consists of three binary pairs.| Star Facts
Gemini (the Twins) is one of the northern zodiac constellations. It is home to the bright stars Pollux and Castor, the open cluster Messier 35, the planetary nebula known as the Medusa Nebula, and the supernova remnant IC 443 (the Jellyfish Nebula).| www.constellation-guide.com
The Caldwell catalogue is a list of 109 bright deep sky objects that can be observed with amateur telescopes. It serves as a supplement to the Messier catalogue and includes deep sky objects in the far southern sky.| www.constellation-guide.com
The Blue Snowball Nebula (NGC 7662, Caldwell 22) is a bright planetary nebula located approximately 5,730 light-years away in the constellation Andromeda.It is visible in small and medium telescopes.| www.constellation-guide.com
Mebsuta, Epsilon Geminorum (ε Gem) is a yellow supergiant star located 840 light-years away in the constellation Gemini. It marks Castor's leg in the constellation figure of the Twins.| Star Facts
Eridanus is one of the largest constellations in the sky. It represents the celestial river. It is home to Achernar, one of the brightest stars in the sky, the nearby star Epsilon Eridani, and the Witch Head Nebula (IC 2118).| www.constellation-guide.com
Propus, Eta Geminorum (η Gem), is the primary component in a triple star system located 700 light-years away in the constellation Gemini. It is a red giant star that marks the foot of Castor.| Star Facts