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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Example Sentences

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

From Salon • Jan. 9, 2023

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

In the portraits of the ladies who belonged to that dissolute court managed by Louis XIV of France, there often appears the dark and ambiguous figure of a black dwarf.

From Time Magazine Archive

Eventually it will fade slowly, first to a white dwarf hen to a black dwarf, and cruise through space in darkness, surrounded by its dead outer planets.

From Time Magazine Archive

When the smoke had circled about the cavern, suddenly a little black dwarf stood before him, and said, "Lord, what are thy commands?"

From Household Tales by Brothers Grimm by Hunt, Margaret