Alpha Centauri is a triple star system in the southern constellation of Centaurus. It consists of three stars: Rigil Kentaurus, Toliman, and Proxima Centauri. Proxima Centauri is the closest star to the Sun at 4.2465 light-years (1.3020 pc).
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not then recognized as such. The first confirmation of the detection occurred in 1992. A different planet, first detected in 1988, was confirmed in 2003. As of 7 November 2024, there are 5,787 confirmed exoplanets in 4,320 planetary systems, with 969 systems having more than one planet. The James Webb Space Telescope (JWST) is expected to discover more exoplanets, and to give more insight into their traits, such as their composition, environmental conditions, and potential for life.
Tau Ceti, Latinized from τ Ceti, is a single star in the constellation Cetus that is spectrally similar to the Sun, although it has only about 78% of the Sun's mass. At a distance of just under 12 light-years from the Solar System, it is a relatively nearby star and the closest solitary G-class star. The star appears stable, with little stellar variation, and is metal-deficient relative to the Sun.
Proxima Centauri is the nearest star to Earth after the Sun, located 4.25 light-years away in the southern constellation of Centaurus. This object was discovered in 1915 by Robert Innes. It is a small, low-mass star, too faint to be seen with the naked eye, with an apparent magnitude of 11.13. Its Latin name means the 'nearest [star] of Centaurus'. Proxima Centauri is a member of the Alpha Centauri star system, being identified as component Alpha Centauri C, and is 2.18° to the southwest of the Alpha Centauri AB pair. It is currently 12,950 AU (0.2 ly) from AB, which it orbits with a period of about 550,000 years.
A planetary system is a set of gravitationally bound non-stellar bodies in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. For example, the Sun together with the planetary system revolving around it, including Earth, form the Solar System. The term exoplanetary system is sometimes used in reference to other planetary systems.
An exomoon or extrasolar moon is a natural satellite that orbits an exoplanet or other non-stellar extrasolar body.
Gliese 581 is a red dwarf star of spectral type M3V which hosts a planetary system, 20.5 light-years away from Earth in the Libra constellation. Its estimated mass is about a third of that of the Sun, and it is the 101st closest known star system to the Sun. Gliese 581 is one of the oldest, least active M dwarfs known. Its low stellar activity improves the likelihood of its planets retaining significant atmospheres, and lessens the sterilizing impact of stellar flares.
Margaret Carol "Maggie" Turnbull is an American astronomer and astrobiologist. She received her PhD in Astronomy from the University of Arizona in 2004. Turnbull is an authority on star systems which may have habitable planets, solar twins and planetary habitability. She is also an expert on the use of the coronagraph in the direct detection of exoplanets.
Any planet is an extremely faint light source compared to its parent star. For example, a star like the Sun is about a billion times as bright as the reflected light from any of the planets orbiting it. In addition to the intrinsic difficulty of detecting such a faint light source, the light from the parent star causes a glare that washes it out. For those reasons, very few of the exoplanets reported as of January 2024 have been observed directly, with even fewer being resolved from their host star.
A Super-Earth or super-terran is a type of exoplanet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively. The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or habitability. The alternative term "gas dwarfs" may be more accurate for those at the higher end of the mass scale, although "mini-Neptunes" is a more common term.
This page describes exoplanet orbital and physical parameters.
HD 10180, also designated 2MASS J01375356-6030414, is a Sun-like star in the southern constellation Hydrus that is notable for its large planetary system. Since its discovery, at least six exoplanets have been observed orbiting it, and some studies have proposed up to nine potential planets, which would make it potentially the largest of all known planetary systems, including the Solar System.
An exoplanet is a planet located outside the Solar System. The first evidence of an exoplanet was noted as early as 1917, but was not recognized as such until 2016; no planet discovery has yet come from that evidence. What turned out to be the first detection of an exoplanet was published among a list of possible candidates in 1988, though not confirmed until 2003. The first confirmed detection came in 1992, with the discovery of terrestrial-mass planets orbiting the pulsar PSR B1257+12. The first confirmation of an exoplanet orbiting a main-sequence star was made in 1995, when a giant planet was found in a four-day orbit around the nearby star 51 Pegasi. Some exoplanets have been imaged directly by telescopes, but the vast majority have been detected through indirect methods, such as the transit method and the radial-velocity method. As of 24 July 2024, there are 7,026 confirmed exoplanets in 4,949 planetary systems, with 1007 systems having more than one planet. This is a list of the most notable discoveries.
Proxima Centauri b, also referred to as Alpha Centauri Cb, is an exoplanet orbiting within the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of the larger triple star system Alpha Centauri. It is about 4.2 light-years from Earth in the constellation Centaurus, making it and Proxima d, along with the currently disputed Proxima c, the closest known exoplanets to the Solar System.
Proxima Centauri c is a controversial exoplanet candidate whose detection could not be recreated, claimed to be orbiting the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of a triple star system.
GJ 3470, proper name Kaewkosin, is a red dwarf star located in the constellation of Cancer, 96 light-years away from Earth. With a faint apparent magnitude of 12.3, it is not visible to the naked eye. It hosts one known exoplanet, GJ 3470 b.
