a gold or bronze star worn on the ribbon of a decoration or medal to represent a second or subsequent award of the same decoration or medal.
b.
a silver star worn in place of five gold or bronze stars.
14.
a white spot on the forehead of a horse.
15.
Heraldry. a mullet.
–adjective
16.
celebrated, prominent, or distinguished; preeminent: a star basketball player; a star reporter.
17.
of or pertaining to a star or stars.
–verb (used with object)
18.
to set with or as with stars; spangle.
19.
to feature as a star: an old movie starring Rudolph Valentino.
20.
to mark with a star or asterisk, as for special notice.
–verb (used without object)
21.
to shine as a star; be brilliant or prominent.
22.
(of a performer) to appear as a star: He starred in several productions of Shaw's plays.
—Idioms
23.
make someone see stars, to deal someone a severe blow causing the illusion of brilliant streaks of light before the eyes: The blow on the head made him see stars, and the next thing he knew he was in the hospital.
24.
thank one's lucky stars, to acknowledge one's good fortune; be grateful: Instead of complaining about hospital bills she should thank her lucky stars she's still alive. Also, thank one's stars.
[Origin: bef. 900; ME sterre, OE steorra; c. OHG sterra; akin to OHG sterno, ON stjarna, Goth stairno, L stella, Gk astr, Skt stṛ]
Stars differ widely in mass, size, temperature, and total energy output, or luminosity. The sun, a typical star, has a mass of about 2 × 1033 grams, a radius of about 7 × 1010 cm, a surface temperature of about 6,000°C;, and a luminosity of about 4 × 1033 erg/sec. More than 90% of all stars have masses between one tenth and 50 times that of the sun. Other stellar quantities vary over a much larger range. The most luminous stars (excluding supernovas) are about ten million times more powerful than the sun, while the least luminous are only one hundredth as powerful. Red giants, the largest stars, are fifteen-hundred times greater in size than the sun; if one were placed at the sun's position, it would stretch to halfway between Jupiter and Saturn. At the opposite extreme, white dwarfs are no larger than the earth, and neutron stars are only a few kilometers in radius.
The visible stars are divided into six classes according to apparent brightness; the brightest are first magnitude and the faintest are sixth magnitude. The stars differ in apparent brightness both because they lie at different distances from us and because they vary in actual or intrinsic brightness. Variable stars do not shine steadily but fluctuate in either a regular or irregular fashion. The supernova, or exploding star, is the most spectacular variable star; the eclipsing binary, where the two stars alternately hide and then reinforce each other's light, is not a true variable.
Light received from a star consists of a spectrum of wavelengths; the hotter the star, the shorter the wavelength at which the light is most intense. The color of a star is closely related to its surface temperature. Red stars have surface temperatures around 3,000°C; and blue-white stars have surface temperatures above 20,000°C; (see spectral class).
Stellar Structure and Stellar Evolution
The theory of stellar structure applies the laws of physics to calculation of the equilibrium configurations of stars. According to this theory, the mass and chemical composition of a star determine all its other characteristics. Because most stars are more than 90% hydrogen, variations in chemical composition are small and have a small effect. Variation in mass is the main factor; a doubling in mass increases the luminosity more than 10 times. For a star to be stable, the compressive force of gravitation must be exactly balanced by the tendency of the gas to expand. Thus, the size and temperature of a star are important, interrelated factors.
Despite the tremendous pressure generated by the massive layers above it, the central region, or core, of a star remains gaseous. This is possible because the core has a temperature of millions of degrees. At this temperature, nuclear energy is released by the fusion of hydrogen to form helium; the principle is the same as that of the hydrogen bomb. By the time nuclear energy reaches the surface of the star, it has been largely converted into visible light with a spectrum characteristic of a very hot body (see black body). The theory of stellar evolution states that a star must change as it consumes its hydrogen in the nuclear reactions that power it. Ultimately each star must die, rarely in a supernova explosion, when its capability for nuclear reactions is exhausted. The heavy atoms created in supernovas (see nucleosynthesis) are spewed out to become part of the interstellar matter from which new stars are continuously formed.
Location and Motion of Stars
The universe contains billions of galaxies, and each galaxy contains billions of stars. The stars visible to the unaided eye are all in our own galaxy, the Milky Way. Stars are not spread uniformly through a galaxy. They are frequently bunched together in star clusters of as many as 100,000 stars. Many stars that appear as single points of light in even the most powerful telescopes are actually systems of two or more stars orbiting one another, bound together by their mutual gravitational attraction; the binary stars are most common among these multiple star systems.
In ancient times, the stars were believed to be motionless; their fixed patterns in the sky were designated as the constellations. It is now known that the stars move through space, although their motion is too small to be detected during a human lifetime without exacting measurements. From the observed proper motion (change in apparent position on the celestial sphere), distance of the star from the earth, and radial velocity (motion along the line of sight), the true velocity of a star through space can be determined. See also brown dwarf.
Bibliography
See C. de Jager, The Brightest Stars (1980); G. O. Abell, Exploration of the Universe (5th ed. 1987); R. J. Taylor, The Stars: Their Structure and Evolution (1994); A. C. Phillips, The Physics of Stars (1994).
![[P]](http://cache.lexico.com/g/r/premium_mh.gif){kind=small}
Audio Help [stahr] Pronunciation Key, noun, adjective, verb, starred, star·ring. 
r, Skt stṛ