- K-type main-sequence star
A K-type main-sequence star (K V), also referred to orange dwarf, are main-sequence (hydrogen-burning) stars of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence stars of luminosity class V and yellow G-type main-sequence stars of luminosity class V. They have masses of from 0.5 to 0.8 times the mass of the Sun[dubious ] and surface temperatures between 3,900 and 5,200 K., Tables VII, VIII. Examples include Alpha Centauri B and Epsilon Indi.
These stars are of particular interest in the search for extraterrestrial life because they are stable on the main sequence for a very long time (15 to 30 billion years, compared to 10 billion for the Sun). This may create an opportunity for life to evolve on terrestrial planets orbiting such stars. Orange dwarfs are about three to four times as abundant as sun-like stars, making planet searches easier.
Formation · Pre–main sequence · Main sequence · Horizontal branch · Asymptotic giant branch · Dredge-up · Instability strip · Red clump · PG1159 star · Mira variable · Planetary nebula · Protoplanetary nebula · Luminous red nova · Luminous blue variable · Wolf–Rayet star · Supernova impostor · Supernova · Hypernova · Hertzsprung–Russell diagram · Color–color diagram
Protostars Luminosity class Spectral classification Remnants Failed and
Nucleosynthesis Structure Properties Star systems Earth-centric
Star names · Arabic names · Chinese names · Most massive · Least massive · Largest · Brightest (Historical) · Most luminous · Nearest (Nearest bright) · Stars with exoplanets · Brown dwarfs · Planetary nebulae · Novae · Notable supernovae · Supernova remnants · Supernova candidates · Timeline of stellar astronomy
Related articles Star portal
Wikimedia Foundation. 2010.
Look at other dictionaries:
O-type main-sequence star — Hertzsprung–Russell Diagram Spectral Type Bro … Wikipedia
Main sequence — A Hertzsprung Russell diagram plots the actual brightness (or absolute magnitude) of a star against its color index (represented as B V). The main sequence is visible as a prominent diagonal band that runs from the upper left to the lower right.… … Wikipedia
Off the Main Sequence — Off the Main Sequence: The Other Science Fiction Stories of Robert A. Heinlein … Wikipedia
Star formation — is the process by which dense parts of molecular clouds collapse into a ball of plasma to form a star. As a branch of astronomy star formation includes the study of the interstellar medium and giant molecular clouds as precursors to the star… … 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
Star — For other uses, see Star (disambiguation) … Wikipedia
Type Ia supernova — A Type Ia supernova is a sub category of cataclysmic variable stars that results from the violent explosion of a white dwarf star. A white dwarf is the remnant of a star that has completed its normal life cycle and has ceased nuclear fusion.… … Wikipedia
Star Wars Episode IV: A New Hope — An original 1977 North American theatrical film poster by Tom Jung Directed by George Lucas … Wikipedia
Star cluster — Star clusters are groups of stars which are gravitationally bound. Two distinct types of star cluster can be distinguished: globular clusters are tight groups of hundreds of thousands of very old stars, while open clusters generally contain less… … Wikipedia
Type II Cepheid — Type II Cepheids are variable stars which pulsate with periods typically between 1 and 50 days. Type II Cepheids are population II stars and are thus old, typically metal poor, low mass objects. Type II Cepheids were historically called… … Wikipedia