Final answer:
A white dwarf is a dense stellar remnant supported by electron degeneracy pressure, about the size of Earth, and extremely dense, making a teaspoonful of its material incredibly heavy.
Step-by-step explanation:
A white dwarf is the compact remnant of a low-mass star that has exhausted its nuclear fuel and has undergone gravitational collapse. These stellar remnants are characterized by several remarkable properties:
- (a) They are supported against further collapse by electron degeneracy pressure, a quantum mechanical effect arising from the Pauli exclusion principle, which prevents electrons from occupying the same quantum state.
- (b) A white dwarf represents the hot, degenerate core of a star that remains after the outer layers have been expelled.
- (c) White dwarfs are incredibly dense, with a mass comparable to the Sun's but compressed to a volume similar to Earth's. Due to this extreme density, a teaspoonful of white dwarf material would weigh about as much as a T-Rex!
- (d) The typical size of a white dwarf is comparable to that of the Earth, meaning they have an Earth-sized radius despite containing nearly a solar mass of material.
It's fascinating that something so massive can be packed into such a small volume, a concept illustrated by the astrophysicist Subrahmanyan Chandrasekhar. His calculations regarding these dense remnants have been fundamental to our understanding of stellar evolution.