Flare star

Flare star

A flare star is a variable star which can undergo unpredictable dramatic increases in brightness for a few minutes. It is believed that the flares on flare stars are analogous to solar flares in that they are due to magnetic reconnection in the atmospheres of the stars. The brightness increase is across the spectrum, from X rays to radio waves. The first known flare stars (V1396 Cygni and AT Microscopii) were discovered in 1924. However, the best-known flare star (UV Ceti) was discovered in 1948, and today flare stars are sometimes known as UV Ceti variables.

Most flare stars are dim red dwarfs, although recent research indicates that less massive brown dwarfs might also be capable of flaring. The more massive RS Canum Venaticorum variables (RS CVn) are also known to flare, but it is understood that these flares are induced by a companion star in a binary system which causes the magnetic field to become tangled. Additionally, nine stars similar to the Sun have also been seen to undergo flare events [cite journal|url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000ApJ...529.1026S&db_key=AST&link_type=ABSTRACT&high=470aa3164700454|date=2000-02|publisher=Astrophysical Journal|last=Schaefer|first=Bradley|title=Superflares on Ordinary Solar-Type Stars|doi=10.1086/308325|journal=The Astrophysical Journal|volume=529|pages=1026] . It has been proposed that the mechanism for this is similar to that of the RS CVn variables in that the flares are being induced by a companion, namely an unseen Jupiter like planet in a close orbit [cite journal|url=http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000ApJ...529.1031R&db_key=AST&link_type=ABSTRACT&high=470aa3164700454|date=2000-02|publisher=Astrophysical Journal|last=Rubenstein|first=Eric|title=Are Superflares on Solar Analogues Caused by Extrasolar Planets?|doi=10.1086/308326|journal=The Astrophysical Journal|volume=529|pages=1031] .

Nearby flare stars

The Sun's nearest stellar neighbor Proxima Centauri is a flare star, as is another near neighbor; Wolf 359. Barnard's Star, the second nearest star system, is also suspected of being a flare star. Flare stars are intrinsically faint, but have been found to distances of 1000 light years from Earth [Kulkarni, S.R. and Rau, A. (2006) [http://adsabs.harvard.edu/abs/2006ApJ...644L..63K "The Nature of the Deep Lens Survey Fast Transients"] Astrophysical Journal.] .

References

External links

* [http://www.aavso.org/vstar/vsots/fall03.shtml www.aavso.org/]
* [http://www.ucm.es/info/Astrof/invest/actividad/flares.html Stellar Flares] - D. Montes, UCM.
* [http://www.webdictionary.co.uk/definition.php?query=flare%20star Definition of a flare star]


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • flare star — Astron. a dwarf star that exhibits sudden increases of magnitude similar to solar flares. Also called UV Ceti star. [1950 55] * * * Star that varies in brightness repeatedly but sporadically, sometimes by more than one magnitude, within a few… …   Universalium

  • flare star — noun a red dwarf star in which luminosity can change several magnitudes in a few minutes • Hypernyms: ↑red dwarf, ↑red dwarf star • Instance Hyponyms: ↑Proxima, ↑Proxima Centauri * * * noun : a star (as a faint red dwarf) tha …   Useful english dictionary

  • flare star — noun Astronomy a dwarf star which displays spasmodic outbursts of radiation, believed to be due to extremely intense flares …   English new terms dictionary

  • 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

  • Star Trek VI: The Undiscovered Country — Theatrical release poster by John Alvin Directed by Nicholas Meyer …   Wikipedia

  • Star Wars Episode IV: A New Hope — An original 1977 North American theatrical film poster by Tom Jung[1] Directed by George Lucas …   Wikipedia

  • Star lifting — is any of several hypothetical processes by which a highly advanced civilization (at least Kardashev II) could remove a substantial portion of a star s matter in a controlled manner for other uses. The term appears to have been coined by David… …   Wikipedia

  • flare — [fler] vi. flared, flaring [ME fleare < ?] 1. a) to blaze up with a sudden, bright light b) to burn unsteadily, as a flame whipped about by the wind 2. to burst out suddenly in anger, violence, etc.: often with up or out 3 …   English World dictionary

  • Star — For other uses, see Star (disambiguation) …   Wikipedia

  • flare — I. noun Etymology: origin unknown Date: 1580 1. a. a fire or blaze of light used especially to signal, illuminate, or attract attention; also a device or composition used to produce such a flare 2. an unsteady glaring light b. solar flare; also a …   New Collegiate Dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”