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Alpha Centauri |
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Alpha Centauri (ăl`fə sĕntôr`ē), brightest star in the constellation Centaurus Centaurus , southern constellation located N and E of Crux, the Southern Cross. It is known especially for its bright stars Alpha Centauri and Hadar. It also contains Centaurus A, a radio galaxy, as well as a globular star cluster visible to the naked eye.
..... Click the link for more information. and 3d-brightest star in the sky; also known as Rigil Kent or Rigil Kentaurus; 1992 position R.A. 14h39.1m, Dec. −60°49'. It is a yellow main-sequence star of the same spectral class spectral class, in astronomy, a classification of the stars by their spectrum and luminosity. In 1885, E. C. Pickering began the first extensive attempt to classify the stars spectroscopically. ..... Click the link for more information. (G2 V) as the sun and of about the same size and mass; its apparent magnitude magnitude, in astronomy, measure of the brightness of a star or other celestial object. The stars cataloged by Ptolemy (2d cent. A.D.), all visible with the unaided eye, were ranked on a brightness scale such that the brightest stars were of 1st magnitude and the ..... Click the link for more information. is −0.26. Actually, Alpha Centauri is a triple-star system, the components being designated A, B, and C. Alpha Centauri C is also called Proxima Centauri because it is the closest star to the earth (other than the sun), at a distance of 4.28 light-years, components A and B are currently 4.34 light-years away. Proxima Centauri orbits about the common center of mass of the system with a period of more than 250,000 years, so that in about 125,000 years it will be more distant than A and B. Alpha CentauriTriple star in the constellation Centaurus, the faintest component of which, Proxima Centauri, is currently the closest star to the Sun (about 4.2 light-years away). The two brighter components are about 0.2 light-year farther from the Sun. As seen from Earth, the system is the third brightest star (after Sirius and Canopus); Proxima is indistinguishable as a separate star to the unaided eye. Alpha Centauri can be seen from Earth's surface only from points south of about 40° N. Alpha Centauri [¦al·fə sen′tȯ·rē] (astronomy) A double star, the brightest in the constellation Centaurus; apart from the sun, it is the nearest bright star to earth, about 4.3 light-years away; spectral classification G2. Also known as Rigil Kent. Alpha Centauri brightest star in Centaurus constellation; closest star to Earth. [Astronomy: NCE, 74] See : Brightness Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
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