White Dwarfs: Cosmic Embers of Stellar Evolution

Definition: A white dwarf is the remnant of a star that has exhausted the nuclear fuel in its core. It is composed mostly of electron-degenerate matter, supported by electron degeneracy pressure. White dwarfs mark the final evolutionary stage for stars like the Sun.

Characteristics:

• Size and Mass: White dwarfs are relatively small but very dense. They typically have masses comparable to the Sun but are roughly the size of Earth, resulting in high densities.
• Temperature: White dwarfs are hot when they form, with surface temperatures often exceeding 100,000 degrees Celsius (180,032 degrees Fahrenheit). However, over time, they gradually cool down, becoming fainter and transitioning from white to red.
• Luminosity: Initially, white dwarfs are highly luminous, shining with the leftover heat from their stellar past. As they cool, their luminosity decreases, and they become fainter.

Formation: White dwarfs form through the final stages of stellar evolution. When a star exhausts the nuclear fuel in its core, it undergoes a series of transformations. If the star is not massive enough to undergo a supernova explosion, it sheds its outer layers, leaving behind a hot and dense core—what is left is the white dwarf.