Dwarf Star

dwarf star: see white dwarf.

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dwarf star

Any star of average or low luminosity, mass, and size, including white dwarf stars and red dwarf stars. Dwarf stars include most main-sequence stars (see Hertzsprung-Russell diagram), including the Sun. Their colour can range from blue to red, corresponding to temperatures varying from over 17,500 °F (10,000 °C) to a few thousand degrees.

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dwarf star [¦dwȯrf ′stär]

(astronomy)

A star that typically has surface temperature of 5730 K, radius of 428,000 miles (690,000 kilometers), mass of 2 × 10³³grams, and luminosity of 4 × 10³³ergs per second. Also known as main sequence star.

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Dwarf Star 

a star of relatively small size and low luminosity. Most dwarf stars form the lower part of the main sequence of the Hertzsprung-Russell diagram. Their average density ranges from 1 to 60 g/cm³. Evidently, all stars of average and small mass are dwarf stars at a certain stage in their evolution, which is characterized by the start of nuclear reactions and the burning of hydrogen in the star’s nucleus. In addition, dwarfs include stars existing in a state of gravitational contraction for a long time because of their very small mass. Dwarf stars have well-developed convection zones and extended chromospheres; therefore, emission lines are encountered in their spectra. A typical dwarf star is our sun. Among dwarfs there are a considerable number of stars with variable characteristics. A large part of the spherical subsystem of the Milky Way Galaxy and of the planar subsystem excluding the spiral arms consists of dwarf stars. The white dwarfs considerably differ in their structure from ordinary (or red) dwarfs.

V. S. AVEDISOVA