Alpha centauri

Alpha Centauri

Alpha Centauri (pronounced: /æl.fə sɛnˈtɔːr.aɪ/) is the closest star system and closest planetary system to Earth's Solar System at 4.37 light-years (1.34 parsecs) from the Sun. It is a triple star system, consisting of three stars: α Centauri A (officially Rigil Kentaurus), α Centauri B (officially Toliman), and α Centauri C (officially Proxima Centauri).

Etymology

The term "Alpha Centauri" comes from the designation established by Johann Bayer in 1603. "Alpha" is the first letter of the Greek alphabet, and "Centauri" is the genitive form of "Centaurus", a southern constellation. "Centaurus" itself is derived from the Greek "Kentauros", a creature in Greek mythology that was half man, half horse.

Related Terms

Star system: A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large number of stars bound by gravitation is generally called a star cluster or galaxy, although, broadly speaking, they are also star systems.

Light-year: A light-year is a unit of length used to express astronomical distances and measures about 9.46 trillion kilometers (5.88 trillion miles) or 63,241 astronomical units.

Parsec: A parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System. One parsec is approximately equal to 31 trillion kilometers (19 trillion miles), or 210,000 astronomical units, and equates to about 3.26 light-years.

Constellation: A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived outline or pattern, typically representing an animal, mythological person or creature, or an inanimate object.

Greek mythology: Greek mythology is the body of myths originally told by the ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the origin and nature of the world, the lives and activities of deities, heroes, and mythological creatures, and the origins and significance of the ancient Greeks' own cult and ritual practices.