Gemini, the Twins ⬅︎

 ↪︎ toggle
The constellation Gemini has been known as the Twins from antiquity. Representing the twins are the bright stars Castor and Pollux which lie just 4° apart (the width of three fingers).

Are Castor and Pollux really twin stars? Even though they have similar brightness, if you look closely you'll see that they are quite different. Pollux is much more yellow than Castor. And Castor isn't a single star at all. A telescope reveals that it is actually three stars very close to each other.

Two popular targets in Gemini include the Eskimo Nebula and the M35 cluster. Use the links below to explore these targets further.
Viewing Gemini, the Twins
LevelEasyRatingBest ViewingLate December to early April
FindGemini is E of Orion. So find red Betelgeuse in Orion and look E for Castor and Pollux. For more help use the 'Constellations of Winter' link below.
Use the map above to find the main stars of Gemini. Try drawing the constellation with stars, lines and labels.
With binoculars many more stars will be visible. M35 Cluster is also visible. See the link below. Take time to explore.
Examine Castor using increasing magnification until you can split it into three separate stars. The M35 Cluster is grand. The Eskimo Nebula is challenging. See the links below.
▶︎ Constellations of Winter  ▶︎ Gemini  ▶︎ Eskimo NebulaM35 Cluster