Gemini

Gemini, the Twins, represents Castor and Pollux from Greek mythology. Pollux, the brighter twin, is the closest giant star to the Sun and was the first giant star confirmed to host an exoplanet. Castor is actually a sextuple star system. The Geminid meteor shower, one of the year's best, radiates from this constellation in December.

The Zodiac family comprises the 12 constellations that lie along the ecliptic — the apparent path of the Sun across the sky over the course of a year. These are among the oldest recognized constellations, with origins in Babylonian astronomy dating back over 3,000 years. The ecliptic crosses each zodiac constellation at different widths, meaning the Sun spends varying amounts of time in each — from about 7 days in Scorpius to 45 days in Virgo.

Mythology & History

The zodiac constellations carry some of the richest mythological traditions in astronomy. Aries recalls the golden ram whose fleece was sought by Jason and the Argonauts. Gemini represents the twins Castor and Pollux, one mortal and one divine. Leo honors the Nemean Lion slain by Heracles as his first labor. The Babylonians originally used these constellations for agricultural timing, and their astrological associations developed later through Greek and Roman traditions. The modern astronomical boundaries were standardized by the IAU in 1930.

Observation Tips

Zodiac constellations are visible from both hemispheres since they straddle the celestial equator. Each is best observed when it reaches opposition (opposite the Sun in the sky), which occurs roughly six months from the dates when the Sun is in that constellation. The zodiac contains many spectacular deep sky objects: the Orion-adjacent Taurus hosts the Pleiades (M45) and Crab Nebula (M1), Virgo is home to the Virgo Cluster of galaxies, and Sagittarius points toward our galaxy's center with its dense Milky Way star clouds.

Pólux18Nu Gem1 Gem28 Gem38 Gem53 Gem57 Gem64 Gem79 Gem9 GemAlhenaHIP 28597HIP 34733HIP 34735HIP 28617HIP 28625HIP 28640HIP 34738HIP 34740HIP 34749HIP 34751HIP 34763HIP 34764HIP 28684HIP 28695HIP 28697HIP 28723HIP 28736HIP 28742HIP 37861HIP 34773HIP 34775HIP 28773HIP 28791HIP 28806HIP 34591HIP 34594HIP 34604HIP 31427HIP 31435HIP 31483HIP 28472HIP 28537HIP 28548HIP 28561HIP 34663HIP 34668HIP 34671

Frequently Asked Questions

What is the Gemini constellation?
Gemini (Gem) is one of the 88 IAU-recognized constellations in the Northern hemisphere. Gemini, the Twins, represents Castor and Pollux from Greek mythology. Pollux, the brighter twin, is the closest giant star to the Sun and was the first giant star confirmed to host an exoplanet. Casto
How many stars are cataloged in Gemini?
StarFYI currently catalogs 1,471 stars in the constellation Gemini.
What is the brightest star in Gemini?
The brightest star in Gemini is Pollux.
How large is the Gemini constellation?
Gemini covers 513.76 square degrees of the sky.
What family does Gemini belong to?
Gemini belongs to the Zodiac Family of constellations.