A constellation of the zodiac, representing the twins Castor and Pollux of Greek mythology. The Sun lies in Gemini for the last week of June and the first three weeks of July. The constellation's brightest stars are Castor (Alpha Geminorum) and Pollux (Beta Geminorum). Zeta Geminorum is a Cepheid that varies between magnitudes 3.6 and 4.2 in a period of 10.2 days. Eta Geminorum is a red-giant semiregular variable that ranges between magnitudes 3.1 and 3.9. M35 is a 5th-magnitude open cluster; NGC 2392 is the Eskimo Nebula. The Geminid meteors radiate from the constellation every December.
Subjects: Astronomy and Astrophysics.