Type of Star: Stellar Core Remnant (stellar evolution phase)
Mass: 10 solar mass (average)
First Discovered: January 31st, 1783
Discovered by: William Herschel
Examples: Sirius B and Procyon B
19 White Dwarf Star Facts for Kids
A white dwarf is a star that has depleted its fuel supply and is in the last stage of stellar evolution.
A white dwarf is also called a degenerate dwarf.
The name white dwarf was coined by Dutch-American astronomer Willem Luyten in 1922.
The first white dwarf star to be discovered was Sirius B in 1844, by German astronomer Friedrich Bessel. Friedrich noticed that the star Sirius had a slight back and forth motion, like it was orbiting an object he couldn't see. In 1863, Alvan Clark spotted what is now called Sirius B. It would eventually be classified as a white dwarf.
The nearest and brightest white dwarf star is Sirius B at 8.66 light-years.
Main-sequence stars that have between 0.07 and 10 solar mass will become a white dwarf.
Current estimates put the number of white dwarf stars in the Milky Way galaxy at 10 billion.
The average mass of a white dwarf is between 0.5 and 0.7 solar mass.
The mass of a white dwarf can be as low as 0.17 and as high as 1.35 solar mass.
The average density of a white dwarf is one million times greater than the density of our sun.
The surface temperature of a white dwarf can range from 4,892 and 450,000 degrees Fahrenheit (lowest and highest discovered to date).
The dimmest white dwarf star is PSR J2222-0137 B, and it's so dim it cannot be observed.
The biggest white dwarf star discovered is RE J0317-853 at 1.35 solar mass.
The smallest white dwarf star discovered is SDSS J091709.55+463821.8 at 0.17 solar mass.
The oldest white dwarf star is tied between WD 0346+246 and SDSS J110217.48+411315.4 at 12 billion years old.
The youngest white dwarf star is SDSS J0003+0718 at roughly 13 million years old.
Astronomers believe it could take some white dwarfs hundreds of billions of years to cool completely.
A black dwarf is the theoretical name for a white dwarf that's cooled and no longer emits significant heat or light.
Due to the estimated amount of a white dwarf needs to be considered a black dwarf astronomers don't believe they currently exist in the universe.