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physical object > natural object > celestial body > star > composite spectrum star > symbiotic star |
symbiotic star (combination variable) | ||||
subject | fact |
symbiotic star | has synonym combination variable | |
has definition Object exhibiting a spectrum corresponding to a low-temperature star (generally a giant) plus emission lines corresponding to a hot plasma. | ||
has definition A term originally used by P. Merrill to describe stars of two essentially dissimilar kinds which seem to occur together and which seem to "need" each other. In practice, it has come to signify a peculiar group of objects (usually spectral type Me) that display a combination of low-temperature absorption spectra and high-temperature emission lines. These objects undergo semiperiodic nova-like outbursts and display the spectral changes of a slow nova superposed on the features of a late-type star. Their spectra are midway between those of planetary nebulae and true stellar objects. A symbiotic star is now usually taken to be a small, hot, blue star surrounded by an extensive variable envelope. As of 1973 about 30 were known. | ||
is a kind of composite spectrum star | ||
is a kind of variable | ||
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 | ||
star | has star surface temperature | |
has spectral type | ||
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 | ||
celestial body | has spectra | |
physical object | has location or center of gravity | |
has angular momentum | ||
has momentum | ||
has temperature | ||
has volume | ||
has extent |
Kinds of symbiotic star :
Next composite spectrum star: VV Cep star Up: composite spectrum star, variable