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physical object > natural object > celestial body > star > late star

late star
subject			fact

late star	has spectral type cooler than G2
	has definition Star with spectral type later than the sun (G2).
	is a kind of star
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
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 late star :

• carbon star (9 kinds, 41 facts) - In the HD system, a rather loose category of peculiar red-giant star, usually of spectral types R and N, whose spectra show strong bands of C₂, CN, or other carbon compounds and unusually high abundances of lithium. Carbon stars resemble S stars in the relative proportion of heavy and light metals, but they contain so much carbon that these bands dominate their spectra. (C2,0. The number following the comma is an abundance parameter.)
• CN-strong star (3 facts) - Late type giant with strong CN bands. Metallic lines are also stronger than in normal giants.
• G star (19 kinds, 195 facts) - Spectral type for yellow stars., Yellowish star in which the H and K lines of Ca II have become dominant and in which a tremendous profusion of spectral lines of both neutral and ionized metals, particularly iron, begins to show. The Balmer lines of hydrogen are still recognizable. Examples are the Sun and Capella.
• H and K emission line star (4 facts) - Late objects (F4 to M), which exhibit emission features in their Ca II HK lines.
• K star (27 kinds, 273 facts) - Cool star with spectral type K with spectra resembling those of sunspots, in which the hydrogen lines have been greatly weakened. The HK lines (q.v.) reach their greatest intensity. Strongest lines are Ca I (4227 Å) and the G-band (4303 Å).
• M star (12 kinds, 105 facts) - Spectral type for red stars, such as Betelgeuse, Antares, and Proxima Centauri., Star of spectral type M are cool red stars with surface temperatures of less than 3600 K whose spectra are dominated by molecular bands, especially those of TiO. M dwarfs are the most numerous type in our galaxy., Having a spectral type of M, that is, red like Betelgeuse and Antares.
• S star (1 kind, 8 facts) - Red-giant stars of spectral type S are similar to M stars except that the dominant oxides are those of the metals of the fifth period (Zr, Y, etc.) instead of the third (Ti, Sc, V). They also have strong CN bands and contain spectral lines of lithium and technetium. Pure S stars are those in which ZrO bands are very strong and TiO bands are either absent or only barely detectable. Almost all S stars are LPVs. (S1,0. The number following the comma is an abundance parameter.) Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, Late type giants (K5 to M) showing distinct bands of ZrO. Jaschek, C., Jaschek, M. 1995 The Behavior of Chemical Elements in Stars, Cambridge University Press, Red-giant star of spectral type S are similar to M stars except that the dominant oxides are those of the metals of the fifth period (Zr, Y, etc.) instead of the third (Ti, Sc, V). They also have strong CN bands and contain spectral lines of lithium and technetium. Pure S stars are those in which ZrO bands are very strong and TiO bands are either absent or only barely detectable. Almost all S stars are LPVs. (S1,0. The number following the comma is an abundance parameter.), Late type giant (K5 to M) showing distinct bands of ZrO.
• semiregular variable (2 kinds, 15 facts) - A class of giant and supergiant pulsating stars of spectral class M, K, N, R, or S with a periodic (or semiperiodic) light curve of varying amplitude.
• T Tauri star (4 kinds, 22 facts) (nebular variable) - Luminous variable stars with low effective temperatures and strong emission lines, associated with interstellar gas clouds and found in very young clusters. They are believed to be still in the process of gravitational contraction from their protostellar phase and have not yet arrived at the main sequence and begun to burn hydrogen., Late type irregular variables associated with bright or dark nebulosity. The spectrum exhibits emission in both CaII and H lines., Eruptive variable subgiant star associated with interstellar matter and believed to be still in the process of gravitational contraction on their way to the main sequence. They are found only in nebulae or very young clusters. They have low-temperature (G-M) spectra with strong emission lines and broad absorption lines. Their absolute magnitudes are brighter than those of main-sequence stars of similar spectral types. They have a high lithium abundance. T Tau itself is dG5e. (sometimes called RW Aurigae stars), Also called T Tauri variable, a type of variable star of spectral classification F, G or K (giants above the main sequence on the Hertzsprung-Russell diagram) that loses an appreciable proportion of its mass in its (irregular) more luminous periods, and is thus surrounded by volumes of gas and dust.
• weak line star (2 kinds, 10 facts) - Late stars in which the lines of all metals are weakened when compared with normal stars of the same temperature. Also called metal-weak stars.

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