Alpha Centauri is a triple star system, with its two main stars, Alpha Centauri A and Alpha Centauri B, being a binary component. The AB designation, or older A×B, denotes the mass centre of a main binary system relative to companion star (s) in a multiple star system.
The large proper motion of Alpha Centauri AB was discovered by Manuel John Johnson, observing from Saint Helena, who informed Thomas Henderson at the Royal Observatory, Cape of Good Hope of it.
Alpha Centauri A , also known as Rigil Kentaurus, is the principal member, or primary, of the binary system. It is a solar-like main-sequence star with a similar yellowish colour, whose stellar classification is spectral type G2 V; it is about 10 percent more massive than the Sun, with a radius about 22 percent larger.
Though not visible to the naked eye, Proxima Centauri is the closest star to the Sun at a distance of 4.24 light-years (1.30 pc), slightly closer than Alpha Centauri AB.
Alpha Centauri is the brightest object in the constellation of Centaurus (top left). α Centauri ( Latinised to Alpha Centauri) is the system's designation given by Johann Bayer in 1603.
The name is Latinized from α Centauri, and abbreviated Alpha Cen or α Cen. It is a triple star system, consisting of three stars: α Centauri A (officially Rigil Kentaurus ), ...
Alpha Centauri AB is the bright star to the left, which forms a triple star system with Proxima Centauri, circled in red. The bright star system to the right is Beta Centauri. Observation data. Epoch J2000.0 Equinox J2000.0. Constellation.
The Alpha Centauri system consists of Alpha Centauri A, a yellow main sequence star of the spectral type G2V, Alpha Centauri B, an orange main sequence star with the stellar classification K1V, and Alpha Centauri C , a faint red dwarf of the spectral type M5.5Ve.
The distance of Alpha Centauri AB is now believed to be 4.37 light years, or about 41.34 trillion kilometres, with a parallax of 754.81 ± 4.11 milliarcseconds. Proxima Centauri is slightly closer, at 4.244 light years.
There are two confirmed planets in the Alpha Centauri system, both orbiting Proxima Centauri. Designated Proxima Centauri b (or Alpha Centauri Cb) and Proxima Centauri c (Alpha Centauri Cc), these are the nearest known exoplanets to the Sun. Proxima b is a terrestrial planet, while Proxima c is believed to be a super-Earth or mini-Neptune.
As the nearest star system to the Sun, Alpha Centauri is a target for several interstellar exploration missions that are still in concept stage and will likely remain so for the foreseeable future because the technology that would reduce travel time to the star system does not yet exist.
Alpha Centauri. by admin. 2020-08-30. 2021-07-10. Alpha Centauri (α Cen) is a triple star system located in the constellation Centaurus. It is the nearest star system to the Sun and the third brightest point of light in the sky outside the solar system, after Sirius and Canopus. It outshines the northern luminaries Arcturus, Vega and Capella.
The star appears so big just because of the scattering of light by the telescope’s optics as well as in the photographic emulsion. Image: ESO/DSS 2
Proxima Centauri hosts the nearest planetary system to Earth. Two exoplanets have been confirmed to be orbiting the star. Proxima Centauri b, an Earth-sized planet discovered in 2016, orbits in the star’s habitable zone. Another planet, designated Proxima Centauri c, was confirmed in 2020.
Astronomers designate stars in each constellation by letters of the Greek alphabet--alpha, beta, gamma, delta and so forth, and "Alpha Centauri" means the brightest star in the constellation of Centaurus, located high in the southern skies.
Only in 1838 were definite parallaxes measured for some of the nearest stars--for Alpha Centauri by Henderson from South Africa, for Vega by Friedrich von Struve and for 61 Cygni by Friedrich Bessel. Such observations demand enormous precision.
In measuring star distances, astronomers frequently use the parsec, the distance to a star whose yearly parallax is 1"--one second of arc. One parsec equals 3.26 light years, but as already noted, no star is that close to us. Alpha Centauri, the sun-like star nearest to our solar system, has a distance of 4.3 years and a parallax of 0.75".
That angle is the parallax of your thumb, viewed from your eyes. The triangle A'B'C has the same proportions as the much larger triangle ABC, and therefore, if the distance B'C to the thumb is 10 times the distance A'B' between the eyes, the distance AC to the far landmark is also 10 times the distance AB.
Estimate the true distance AB, by comparing it to the estimated heights of trees, widths of buildings, distances between power-line poles, lengths of cars etc. The distance to the landmark is 10 times the distance AB.
The Sun's light needs 500 seconds to reach Earth, a bit over 8 minutes, and about 5 hours to reach the the distant planet Pluto. A "light year" is about 1600 times further, an enormous distance.
Alpha Centauri is a triple star system, with its two main stars, Alpha Centauri A and Alpha Centauri B, together comprising a binary component. The AB designation, or older A×B, denotes the mass centre of a main binary system relative to companion star(s) in a multiple star system. AB-C refers to the component of Proxima Centauri in relation to the central binary, being the dist…
α Centauri (Latinised to Alpha Centauri) is the system's designation given by Johann Bayer in 1603. It bears the traditional name Rigil Kentaurus, which is a Latinisation of the Arabic name رجل القنطورس Rijl al-Qinṭūrus, meaning 'the Foot of the Centaur'. The name is frequently abbreviated to Rigil Kent or even Rigil, though the latter name is better known for Rigel (Beta Orionis).
An alternative name found in European sources, Toliman, is an approximation of the Arabic الظليما…
Alpha Centauri's planetary system was the destination in the science fiction space travel television series Lost in Space airing from 1965-68 on CBS, produced by Irwin Allen. It remained so in the reboot with the same name in 2018-20, produced for Netflix. In the earlier series, the Robinson family is sent from Earth to colonize one of the planets; in the reboot, several families are sent.
In modern literature, colloquial alternative names of Alpha Centauri include Rigil Kent (also Rigel Kent and variants; /ˈraɪdʒəl ˈkɛnt/) and Toliman (the latter of which became the proper name of Alpha Centauri B on 10 August 2018 by approval of the International Astronomical Union).
Rigil Kent is short for Rigil Kentaurus, which is sometimes further abbreviated to Rigil or Rigel, though that is ambiguous with Beta Orionis, which is also called Rigel.