Epsilon Eridani

Epsilon Eridani (ε Eri, ε Eridani) is a star in the southern constellation Eridanus, along a declination 9.46° south of the celestial equator. This allows the star to be viewed from most of the Earth's surface. At a distance of 10.5 light years (ly), it has an apparent magnitude of 3.73. It is the third closest of the individual stars or star systems visible to the unaided eye and was the closest star known to host a planet until the discovery of Alpha Centauri Bb. Its age is estimated at less than a billion years. Because of its youth, Epsilon Eridani has a higher level of magnetic activity than the present-day Sun, with a stellar wind 30 times as strong. Its rotation period is 11.2 days at the equator. Epsilon Eridani is smaller and less massive than the Sun, and has a comparatively lower level of elements heavier than helium. Astronomers categorize it as a main-sequence star of spectral class K2, which means that energy generated at the core through nuclear fusion of hydrogen is emitted from the surface at a temperature of about 5,000 K, giving the star an orange hue.

The motion of this star along the line of sight to the Earth, known as the radial velocity, has been regularly observed for more than twenty years. Periodic changes in this data yielded evidence of a giant planet orbiting Epsilon Eridani, making it one of the nearest extrasolar system with a candidate exoplanet. This object, Epsilon Eridani b, was formally announced in 2000 by a team of astronomers led by Artie Hatzes. Current data indicate that this planet orbits with a period of about 7 years at a mean separation of 3.4 astronomical units (AU), where 1 AU is the mean distance between the Earth and the Sun. Although this discovery has been controversial because of the amount of background noise in the radial velocity data, many astronomers now regard the planet as confirmed.

The system includes two belts of rocky asteroids: one at about 3 AU and a second at about 20 AU, whose structure may be maintained by a hypothetical second planet, Epsilon Eridani c. Epsilon Eridani harbors an extensive outer debris disk of remnant planetesimals left over from the system's formation.

The designation for this star was established in 1603 by Johann Bayer. It may be a member of the Ursa Major Moving Group of stars that share a similar motion through the Milky Way, implying these stars shared a common origin in an open cluster. Its nearest neighbor, the binary star system Luyten 726-8, will have a close encounter with Epsilon Eridani in approximately 31,500 years when they will be separated by about 0.93 ly. As one of the nearest Sun-like stars with the potential for a planet that may harbor life, Epsilon Eridani has been the target of SETI searches. The star appears in science fiction stories and has been suggested as a destination for interstellar travel.

Read more about Epsilon EridaniObservation History, Properties, Planetary System

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Epsilon Eridani In Fiction - Film and Television - Star Trek
... reference works such as the Star Trek Spaceflight Chronology, Epsilon Eridani has been suggested as the possible star system of the planet Vulcan, the home ... distance as consistent with that of 40 Eridani, and the authorized (but non-canonical) Star Trek book Star Trek Star Charts identifies it as such, while ... The 40 Eridani location is furthermone attested by Roddenberry himself and in a statement by Commander Tucker in Star Trek Enterprise that "Vulcan is 16 light years from Earth"—as is ...
Epsilon Eridani - Planetary System - Possible Planets - Potential Habitability
... Epsilon Eridani is a target for planet finding programs because it has properties that allow an Earth-like planet to form ... the subject of multiple studies on whether an interstellar probe can be sent to Epsilon Eridani ... The orbital radius at which the stellar flux from Epsilon Eridani matches the solar constant—where the emission matches the Sun's output at the orbital distance of the Earth—is 0.61 astronomical ...
Epsilon Eridani In Fiction - Film and Television - Other Film and Television
... moderating ocean cover, and an eccentric elliptical orbit around Epsilon Eridani, it suffered severe winters and heavy glaciation during its aposiderions ... the Demeter City police force on the planet Altor in the Epsilon Eridani system ... station, a five-mile long O'Neill cylinder located in the Epsilon Eridani star system at the fifth Lagrangian point between the fictional planet Epsilon III ...
Epsilon Eridani In Fiction - Games
... Epsilon Eridani is one of the inhabited worlds closest to Terra ... Dukou (Epsilon Eridani I), a habitable but glacier-bound world, is the location of the Manchurian semi-penal colony Xixiang ... In the game, the Epsilon Eridani system is the main point of access to the Latin systems ...