black dwarf

American  

[blak dwawrf] / ˈblæk ˈdwɔrf /

noun

black dwarfs plural

1. Astronomy. the end state of a white dwarf that has cooled and faded over trillions of years until it emits no light; a theoretical entity, since the time span required is greater than the current age of the universe.

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black dwarf Scientific  

1. The theoretical celestial object that remains after a white dwarf has used up all of its fuel and cooled off completely to a solid mass of extremely dense, cold carbon. A white dwarf will eventually become a black dwarf unless it has a companion star from which it can take sufficient mass to pass the Chandrasekhar limit and collapse into a neutron star or black hole. No black dwarf has ever been observed. Because the estimated cooling time for a white dwarf is in the trillions of years, it is unlikely that there are many, if any, black dwarfs in our universe, which is only 12 to 18 billion years old.

2. See Note at dwarf star

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Other Word Forms

Noun Inflected Forms

• black dwarfs
  plural

Example Sentences

However, astrophysicists calculate that this type of star, known as a black dwarf, would take so long to cool that there are not yet any black dwarf stars anywhere in the entire universe.

From Salon • Jan. 9, 2023

Earth's sun will eventually end its life as a white, then black, dwarf.

From Salon • Jan. 9, 2023

Slowly it will cool until it is first a white dwarf, still glowing, then a cold black dwarf, a cinder.

From Time Magazine Archive

As the millenniums pass, the white dwarf gradually loses its heat, turning first yellow, then red; eventually, its fires burn out entirely, leaving behind a "black dwarf," a cold cinder in the graveyard of space.

From Time Magazine Archive

Metem running on towards her, as he went perceived a shape, which looked like that of a black dwarf, slip from the shadow of the tree into some bushes beyond where it was lost.

From Elissa by Haggard, Henry Rider