A report on Alpha Centauri and Centaurus

Alpha Centauri is the brightest object in the constellation of Centaurus (top left).
Centaurus in the southwestern sky, shortly after sunset.
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.
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.
The relative sizes and colours of stars in the Alpha Centauri system, compared to the Sun
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.
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.
Centaurus, 1602
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

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.

- Centaurus

To the naked eye, the two main components appear to be a single star with an apparent magnitude of −0.27, the brightest star in the southern constellation of Centaurus and the third-brightest in the night sky, outshone only by Sirius and Canopus.

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

6 related topics with Alpha

Overall

Depiction of the Crux by João Faras in May 1500

Crux

2 links

Constellation of the southern sky that is centred on four bright stars in a cross-shaped asterism commonly known as the Southern Cross.

Constellation of the southern sky that is centred on four bright stars in a cross-shaped asterism commonly known as the Southern Cross.

Depiction of the Crux by João Faras in May 1500
Southern Cross from New Zealand
Deep exposure of Crux, Coalsack Nebula, and IC 2944
Locating the south celestial pole
The constellation Crux as it can be seen by the naked eye
Crux with clouds, from Cape Town
Crux, appearing on a number of flags and insignia

Nearby to the southeast is a large dark nebula spanning 7° by 5° known as the Coalsack Nebula, portions of which are mapped in the neighbouring constellations of Centaurus and Musca.

Projecting a line from γ to α Crucis (the foot of the crucifix) approximately 4 1⁄2 times beyond gives a point close to the Southern Celestial Pole which is also, coincidentally, where intersects a perpendicular line taken southwards from the east-west axis of Alpha Centauri to Beta Centauri, which are stars at an alike declination to Crux and of a similar width as the cross, but higher magnitude.

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.

Proxima Centauri

1 links

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.
300x300px
300x300px
300x300px

Proxima Centauri is a small, low-mass star located 4.2465 ly away from the Sun in the southern constellation 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.

Beta Centauri

1 links

Beta Centauri is a triple star system in the southern constellation of Centaurus.

The Boorong people indigenous to what is now northwestern Victoria, Australia named it Bermbermgle (together with α Centauri), two brothers who were noted for their courage and destructiveness, and who spear and kill Tchingal, "The Emu" (Coalsack Nebula).

Binary system of two stars

Binary star

1 links

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).

Another visible ternary is Alpha Centauri, in the southern constellation of Centaurus, which contains the fourth-brightest star in the night sky, with an apparent visual magnitude of −0.01.

A picture of stars, with a group of appearingly bright blue and white stars. The bright stars together are identified as the asterism Coathanger resembling a coathanger, in the constellation Vulpecula.

Asterism (astronomy)

1 links

Observed pattern or group of stars in the sky.

Observed pattern or group of stars in the sky.

A picture of stars, with a group of appearingly bright blue and white stars. The bright stars together are identified as the asterism Coathanger resembling a coathanger, in the constellation Vulpecula.
Some major asterisms on a celestial map (the projection exaggerates the stretching)
The Big Dipper asterism
The "Teapot" asterism in Sagittarius. The Milky Way appears as "steam" coming from the spout.
The "37" or "LE" of NGC 2169, in Orion. It is visible through a pair of binoculars.

The Southern Cross including the first-magnitude stars Acrux and Mimosa, west of the Carina Nebula (one of five first-magnitude deep-sky objects), and with the first-magnitude stars Alpha Centauri (the closest star to the Sun) and Beta Centauri pointing at the cross, distinguishing the cross from less bright and similar asterisms like the Diamond Cross or False Cross.

The Southern Cross is an asterism by name, but the whole area is now recognised as the constellation Crux. The main stars are Alpha, Beta, Gamma, Delta, and arguably also Epsilon Crucis. Earlier, Crux was deemed an asterism when Bayer created it in Uranometria (1603) from the stars in the hind legs of Centaurus, decreasing the size of Centaur. These same stars were probably identified by Pliny the Elder in his Naturalis Historia as the asterism 'Thronos Caesaris.'

Epsilon Centauri

0 links

Epsilon Centauri (ε Cen, ε Centauri) is a star in the southern constellation of Centaurus.

In Chinese, 南門 (Nán Mén), meaning Southern Gate, refers to an asterism consisting of ε Centauri and α Centauri.