The Twins

Abbreviation: Gem
Genitive: Geminorum

The constellation of Gemini

Gemini is a member of the zodiac. This is one of the most ancient of constellations, harking back to Babylonia where the stars Castor and Pollux were known as the Great Twins. In Greek mythology, this constellation is associated with the twin brothers Castor and Pollux. Their mother was Leda but Castor's father was the mortal Tyndareus, the king of Sparta, and Pollux's father was the king of the gods, Zeus. Zeus placed them in the sky after Castor was killed; thus the brothers are together forever.

Notable Features

Designation Name Description
Geminids These December meteors are of average speed and brightness but the Geminid meteor shower is one of the richest in the calendar, peaking at over 100 meteors per hour. The parent body is not a comet but an asteroid, 3200 Phaethon.
α Gem Castor Although it appears as a binary through a small telescope, Castor is actually a six-star system.
β Gem Pollux Although the β (beta) star in the constellation, first magnitude Pollux is actually the brightest star in the constellation. An exoplanet has been detected in orbit around this luminous object.
γ Gem Alhena
δ Gem Wasat
ε Gem Mebsuta
ζ Gem Mekbuda This is a Cepheid variable with a period of around 10 days.
η Gem Propus Also known unofficially as Tejat Prior, this star is a pulsating red giant. William Herschel discovered the planet Uranus on 13 March 1781 near this star.
μ Gem Tejat Posterior The name of the star is not officially recognised by the IAU.
M35 This is an open star cluster which is easy to see through binoculars.
C63 Eskimo Nebula, Clown Face Nebula This planetary nebula is just visible through a small telescope.