white dwarf

American  

noun

Astronomy.

1. a star, approximately the size of the earth, that has undergone gravitational collapse and is in the final stage of evolution for low-mass stars, beginning hot and white and ending cold and dark black dwarf.

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white dwarf British  

noun

1. one of a large class of small faint stars of enormous density (on average 10 ⁸ kg/m³) with diameters only about 1 per cent that of the sun, and masses less than the Chandrasekhar limit (about 1.4 solar masses). It is thought to mark the final stage in the evolution of a sun-like star

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white dwarf Scientific  

1. A small, extremely dense star characterized by high temperature and luminosity. A white dwarf is believed to be in its final stage of evolution, having either used up most of its nuclear fuel in its main-sequence stage, or else moved through a giant stage and shed any remaining fuel in its outer layer as a planetary nebula, leaving only a glowing core. Some 10 percent of all stars in the Milky Way are white dwarfs, but despite their intrinsic luminosity, they are so small that none are visible to the naked eye.

2. See Note at dwarf

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white dwarf Cultural  

1. A kind of star about the size of the Earth. White dwarfs represent a final stage of the life cycle of stars similar to the sun; they are formed when the stars use up their fuel and can no longer support nuclear reactions.

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Etymology

Origin of white dwarf

First recorded in 1920–25

Example Sentences

The researchers found that the radio waves are likely produced where the stars' magnetic fields collide and interact with the stream of charged material flowing toward the white dwarf.

From Science Daily • Jun. 2, 2026

As the white dwarf pulls gas from its companion, the material heats up and emits X-rays.

From Science Daily • Jun. 2, 2026

These findings show that γ Cas and similar stars belong to a class of Be + white dwarf binary systems that had long been predicted but never clearly observed.

From Science Daily • Mar. 25, 2026

If it is more like our Sun, it will continue to lose material until only its dense core remains as a white dwarf, which will gradually cool over vast stretches of time.

From Science Daily • Mar. 17, 2026

A two-wheeled cart went rumbling past them, pulled by a white dwarf elephant.

From "A Dance with Dragons" by George R. R. Martin