- Red supergiant
Red supergiants (RSGs) are
supergiant stars (luminosity class I) of spectral type K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive. Betelgeuseand Antaresare the best known examples of a red supergiant.
Stars with more than about 10
solar masses after burning their hydrogen become red supergiants during their helium-burning phase. These stars have very cool surface temperatures (3500–4500 K), and enormous radii. The five largest known red supergiants in the Galaxy are VY Canis Majoris, Mu Cephei, KW Sagitarii, V354 Cephei, and KY Cygni, which all have radii about 1500 times that of the sun (about 7 astronomical units, or 7 times as far as the Earth is from the sun). The radius of most red giants is between 200 and 800 times that of the sun, which is still enough to reach from the sun to Earth and beyond.
These massively large stars are little more than "hot vacuums", having no distinct
photosphereand simply "tailing off" into interstellar space. They have a slow, dense, stellar windand if their core's nuclear reactions slow for any reason (such as transitioning between shell fuels) they may shrink into a blue supergiant. A blue supergiant has a fast but sparse stellar wind and causes the material already expelled from the red supergiant phase to compress into an expanding shell.
The mass of many red supergiants allow them to eventually fuse elements up to
iron. Near the end of their lifetimes, they will develop layers of heavier and heavier elements with the heaviest at the core.
The red supergiant phase is relatively short, lasting only a few hundred thousand to a million or so years. The most massive of the red supergiants are thought to evolveto
Wolf-Rayet stars, while lower mass red supergiants will likely end their lives as a type II supernova.
The red sun around which the fictitious planet Krypton orbits in both "Superman" and "
Superman Returns" is also a red supergiant (as opposed to that of a red dwarfstar in the comics) that undergoes a supernovaexplosion, causing Krypton's destruction by means of the shockwaves emitted by the dying star (in the comic series, Krypton was destroyed by the planet's unstable cores).
List of stellar angular diameters
* [http://www.physorg.com/news5519.html Hubble pinpoints red supergiant that exploded.]
* [http://cse.ssl.berkeley.edu/bmendez/ay10/2000/cycle/massive.html The Stellar Lifecycla: Massive Red Supergiant]
* [http://www.astro.uu.se/~bf/movie/dst35gm04n26/movie.html Image and video simulations of a red supergiant]
Wikimedia Foundation. 2010.
См. также в других словарях:
red supergiant — noun A very large, red star, such as Betelgeuse and Antares … Wiktionary
Supergiant — Supergiants are among the most massive stars. In the Hertzsprung Russell diagram they occupy the top region of the diagram. In the Yerkes spectral classification supergiants are class Ia (most luminous supergiants) or Ib (less luminous… … Wikipedia
Red giant — A red giant is a luminous giant star of low or intermediate mass (roughly 0.5 ndash;10 solar masses) that is in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius immense and the surface temperature … Wikipedia
Red Dwarf ships — The British sci fi comedy Red Dwarf prominently features many different spaceships . Three feature regularly, and several have appeared for one or two episodes only but are nonetheless important to Red Dwarf continuity or well known among the fan … Wikipedia
Supergiant — The largest type of Red Stars. These stars have diameters over 400 times larger than that of our Sun, but they are not very dense, maybe only 40 times more than our Sun … The writer's dictionary of science fiction, fantasy, horror and mythology
Blue supergiant — Blue supergiants (BSGs) are supergiant stars (luminosity class I) of spectral type O or B.They are extremely hot and bright, with surface temperatures of between 20,000 to 50,000°C. They typically have 10 to 50 solar masses on the Hertzsprung… … Wikipedia
Yellow supergiant — A yellow supergiant (YSG) is a supergiant star of spectral type F or G. [p. 366, The evolution of massive stars with mass loss, Cesare Chiosi and Andre Maeder, Annual review of astronomy and astrophysics 24 (1986), pp. 329 ndash;375.… … Wikipedia
star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… … Universalium
Stellar classification — In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are… … Wikipedia
Outline of astronomy — Mauna Kea in Hawaii is one of the world s premier observatory sites. Pictured is the W. M. Keck Observatory, an optical interferometer. The following outline is provided as an overview of and topical guide to astronomy: Astronomy – studies the… … Wikipedia