A report on Alpha Centauri and Proxima Centauri

Alpha Centauri is the brightest object in the constellation of Centaurus (top left).
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.
Apparent and true orbits of Alpha Centauri. The A component is held stationary, and the relative orbital motion of the B component is shown. The apparent orbit (thin ellipse) is the shape of the orbit as seen by an observer on Earth. The true orbit is the shape of the orbit viewed perpendicular to the plane of the orbital motion. According to the radial velocity versus time, the radial separation of A and B along the line of sight had reached a maximum in 2007, with B being further from Earth than A. The orbit is divided here into 80 points: each step refers to a timestep of approx. 0.99888 years or 364.84 days.
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The relative sizes and colours of stars in the Alpha Centauri system, compared to the Sun
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Relative positions of Sun, Alpha Centauri AB and Proxima Centauri. Grey dot is projection of Proxima Centauri, located at the same distance as Alpha Centauri AB.
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The two bright stars at the lower right are Alpha (right) and Beta Centauri (left, above antenna). A line drawn through them points to the four bright stars of the Southern Cross, just to the right of the dome of the Danish 1.54 m telescope at La Silla Observatory in Chile.
Alpha Centauri AB taken in daylight by holding a Canon Powershot S100 in line with the eyepiece of a 110-mm refractor. The photo is one of the best frames of a video. The double star is clearly visible.
View of Alpha Centauri from the Digitized Sky Survey-2
Alpha Centauri A is of the same stellar type G2 as the Sun, while Alpha Centauri B is a K1-type star.
Closest stars to the Sun
Distances of the nearest stars from 20,000 years ago until 80,000 years in the future
Animation showing motion of Alpha Centauri through the sky. (The other stars are held fixed for didactic reasons) "Oggi" means today. "Anni" means years.
The discovery image of Alpha Centauri's candidate Neptunian planet, marked here as "C1".
Looking towards the sky around Orion from Alpha Centauri with Sirius near Betelgeuse, Procyon in Gemini, and the Sun in Cassiopeia generated by Celestia.
Simulated night-sky image with a "W" of stars from Cassiopeia connected by lines, and the Sun, labeled "Sol", as it would appear to the left of the "W"
The Very Large Telescope and Alpha Centauri

It is a triple star system consisting of α Centauri A (officially Rigil Kentaurus), α Centauri B (officially Toliman), and the closest star α Centauri C (officially Proxima Centauri).

- Alpha Centauri

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.

- Proxima Centauri
Alpha Centauri is the brightest object in the constellation of Centaurus (top left).

8 related topics with Alpha

Overall

Artist's conception of Proxima Centauri b as a rocky-like exoplanet, with Proxima Centauri and the Alpha Centauri binary system in the background. The actual appearance of the planet is unknown.

Proxima Centauri b

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Artist's conception of Proxima Centauri b as a rocky-like exoplanet, with Proxima Centauri and the Alpha Centauri binary system in the background. The actual appearance of the planet is unknown.
Velocity of Proxima Centauri towards and away from the Earth as measured with the HARPS spectrograph during the first three months of 2016. The red symbols with black error bars represent data points, and the blue curve is a fit of the data. The amplitude and period of the motion were used to estimate the planet's minimum mass.
Overview and comparison of the orbital distance of the habitable zone.
An angular size comparison of how Proxima will appear in the sky seen from Proxima b, compared with how the Sun appears in our sky on Earth. Proxima is much smaller than the Sun, but Proxima b is very close to its star.
Artist's conception of the surface of Proxima Centauri b. The Alpha Centauri AB binary system can be seen in the background, to the upper right of Proxima.

Proxima Centauri b (or Proxima b), sometimes referred to as Alpha Centauri Cb, is an exoplanet orbiting in the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of the triple star system Alpha Centauri.

Binary system of two stars

Binary star

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System of two stars that are gravitationally bound to and in orbit around each other.

System of two stars that are gravitationally bound to and in orbit around each other.

Binary system of two stars
Edge-on disc of gas and dust present around the binary star system HD 106906
Algol B orbits Algol A. This animation was assembled from 55 images of the CHARA interferometer in the near-infrared H-band, sorted according to orbital phase.
Artist's conception of a cataclysmic variable system
Artist's impression of the binary star system AR Scorpii
Artist rendering of plasma ejections from V Hydrae
Artist's impression of the sight from a (hypothetical) moon of planet HD 188753 Ab (upper left), which orbits a triple star system. The brightest companion is just below the horizon.
Schematic of a binary star system with one planet on an S-type orbit and one on a P-type orbit
The two visibly distinguishable components of Albireo
Luhman 16, the third closest star system, contains two brown dwarfs.
Planet Lost in the Glare of Binary Stars (illustration)

Orbital periods can be less than an hour (for AM CVn stars), or a few days (components of Beta Lyrae), but also hundreds of thousands of years (Proxima Centauri around Alpha Centauri AB).

Centaurus in the southwestern sky, shortly after sunset.

Centaurus

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Bright constellation in the southern sky.

Bright constellation in the southern sky.

Centaurus in the southwestern sky, shortly after sunset.
The two bright stars are (left) Alpha Centauri and (right) Beta Centauri. The faint red star in the center of the red circle is Proxima Centauri.
Centaurus in the Firmamentum Sobiescianum of Johannes Hevelius. This image is reversed from what one sees looking at the sky — it is as though one is looking at the "celestial sphere" from the outside.
Centaurus, 1602

Notable stars include Alpha Centauri, the nearest star system to the Solar System, its neighbour in the sky Beta Centauri, and V766 Centauri, one of the largest stars yet discovered.

Alpha Centauri is a triple star system composed of a binary system orbited by Proxima Centauri, currently the nearest star to the Sun.

Artistic depiction of Proxima Centauri d, with Alpha Centauri A and B visible in the background

Proxima Centauri d

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Artistic depiction of Proxima Centauri d, with Alpha Centauri A and B visible in the background
Artistic depiction of Proxima Centauri d, with Proxima Centauri and Alpha Centauri A & B visible in the background

Proxima Centauri d (also called Proxima d) is a candidate exoplanet orbiting the red dwarf star Proxima Centauri, the closest star to the Sun and part of the Alpha Centauri triple star system.

Star system named DI Cha. While only two stars are apparent, it is actually a quadruple system containing two sets of binary stars.

Star system

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Small number of stars that orbit each other, bound by gravitational attraction.

Small number of stars that orbit each other, bound by gravitational attraction.

Star system named DI Cha. While only two stars are apparent, it is actually a quadruple system containing two sets of binary stars.
Orbits of the HR 6819 hierarchical triple star system: an inner binary with one star (orbit in blue) and a black hole (orbit in red), encircled by another star in a wider orbit (also in blue).
Subsystem notation in Tokovinin's Multiple Star Catalogue
Sirius A (center), with its white dwarf companion, Sirius B (lower left) taken by the Hubble Space Telescope.
HD 98800 is a quadruple star system located in the TW Hydrae association.

Alpha Centauri is a triple star composed of a main binary yellow dwarf pair (Alpha Centauri A and Alpha Centauri B), and an outlying red dwarf, Proxima Centauri. Together, A and B form a physical binary star, designated as Alpha Centauri AB, α Cen AB, or RHD 1 AB, where the AB denotes this is a binary system. The moderately eccentric orbit of the binary can make the components be as close as 11 AU or as far away as 36 AU. Proxima Centauri, also (though less frequently) called Alpha Centauri C, is much farther away (between 4300 and 13,000 AU) from α Cen AB, and orbits the central pair with a period of 547,000 (+66,000/-40,000) years.

On 24 August 2016, ESO hosted a press conference to discuss the announcement of exoplanet Proxima b at its headquarters in Germany. In this picture, Pete Worden giving a speech.

Breakthrough Starshot

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On 24 August 2016, ESO hosted a press conference to discuss the announcement of exoplanet Proxima b at its headquarters in Germany. In this picture, Pete Worden giving a speech.
A solar sail concept

Breakthrough Starshot is a research and engineering project by the Breakthrough Initiatives to develop a proof-of-concept fleet of light sail interstellar probes named Starchip, to be capable of making the journey to the Alpha Centauri star system 4.37 light-years away.

A flyby mission has been proposed to Proxima Centauri b, an Earth-sized exoplanet in the habitable zone of its host star, Proxima Centauri, in the Alpha Centauri system.

Animated 3D map of the nearest stars, centered on the Sun.

List of nearest stars and brown dwarfs

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This list covers all known stars, brown dwarfs, and sub-brown dwarfs within 20 ly of the Solar System.

This list covers all known stars, brown dwarfs, and sub-brown dwarfs within 20 ly of the Solar System.

Animated 3D map of the nearest stars, centered on the Sun.
Distance and angle conformal map of the celestial neighbourhood within 12 light years of Sol.
Distances of the nearest stars from 20,000 years ago until 80,000 years in the future

The Local Bubble also contains the neighboring G-Cloud, which contains the stars Alpha Centauri and Altair.

The closest system is Alpha Centauri, with Proxima Centauri as the closest star in that system, at 4.2465 light-years from Earth.

Robert T. A. Innes

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Robert Thorburn Ayton Innes FRSE FRAS (10 November 1861 – 13 March 1933) was a Scottish astronomer best known for discovering Proxima Centauri in 1915, and numerous binary stars.

In 1915, he found a faint star fairly close to and sharing the same large proper motion with Alpha Centauri, which until then was believed to be the closest star system to the Sun.