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flare star (UV Ceti star) | ||||
subject | fact |
flare star | has synonym UV Ceti star | |
has definition Dim red dwarf star that suddenly lights up with great - but brief - luminosity, corresponding to an equally powerful but short-lived burst of radio emission. The cause is thought to be a sudden and intense outburst of radiation on or above the star's surface. | ||
has definition A star that emits flares, which can outshine the entire star. Many red dwarfs are flare stars. | ||
has definition A member of a class of dwarf stars (usually dM3e-dM6e) that show sudden, intense outbursts of energy. The flares are usually rare and very short with mean amplitudes of about 0.5-0.6 mag. All known flare stars are intrinsically faint and have emission lines of H I and Ca II. It is generally believed that flares in flare stars have certain properties in common: rapid rise to peak light followed initially by a rapid decline and later by a slower phase that occasionally does not return to a preflare level within practical monitoring times (several hours). An increase in radio emission is often detected simultaneously with the optical outburst. About 30 flare stars are known, all within 20 pc. (In at least one theory, the flare star stage directly follows the T Tauri stage.) | ||
has definition Stars undergoing erratic jumps in brightness (up to a few magnitudes) on time scales of the order of minutes. During the quiescent phase the spectrum is that of an M dwarf with emissions in the CaII and Balmer lines. | ||
is a kind of radio star | ||
is a kind of cataclysmic variable | ||
is a kind of red dwarf | ||
red dwarf | has abundance 70 percent of all stars | |
has spectral type M | ||
cataclysmic variable | has peak brightness | |
has recovery time | ||
has outburst start time | ||
has acronym CV | ||
star | has star surface temperature | |
has V magnitude | ||
has B magnitude | ||
has U magnitude | ||
has position on celestial sphere from the point of view of Earth | ||
has parallax from the point of view of Earth's orbit | ||
has proper motion | ||
has radiation at surface which is diffused out from the hotter core | ||
has energy source gravitational contraction and or fusion | ||
has energy production which takes place primarily within the core | ||
has surface density which depends on luminosity class | ||
has surface temperature greater than 1000 Kelvin | ||
has apparent magnitude | ||
has absolute magnitude | ||
has age | ||
has catalog star catalog | ||
has material hydrogen, helium | ||
has velocity determined from proper motion and radial velocity | ||
has mass greater than 0.08 the sun's mass | ||
dwarf | has symbol d | |
has luminosity class V | ||
celestial body | has spectra | |
variable | has name designated with
| |
has observational problem some difficulty in distinguishing between various kinds | ||
has observable variation time scale within a period of decades | ||
has light curve | ||
has optical brightness variation 0.2 magnitudes or greater | ||
has amplitude | ||
physical object | has location or center of gravity | |
has angular momentum | ||
has momentum | ||
has temperature | ||
has volume | ||
has extent |
Kinds of flare star :
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