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.

---

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

---

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

---

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.

---

Etymology

Origin of white dwarf

First recorded in 1920–25

Example Sentences

See Examples For:

white dwarf

Evidence for white dwarf kicks comes from research led by Kareem El-Badry, an assistant professor of astronomy at Caltech.

From Science Daily ● Jul. 21, 2026

Red dwarfs, however, can produce powerful flares that imitate the ultraviolet signal of a white dwarf, making confirmation more difficult.

From Science Daily ● Jul. 15, 2026

This analysis officially confirmed that all four systems contained white dwarf stars.

From Science Daily ● Jul. 15, 2026

The new observations revealed that all four nearby red dwarfs were concealing white dwarf companions.

From Science Daily ● Jul. 15, 2026

There should therefore be, as there are, many cases of binary stars, one component a red giant, the other a white dwarf.

From "Cosmos" by Carl Sagan