Question

Choose the correct statements from the following list referring to white dwarfs.

A) White dwarfs cool slowly because they are small and eventually fade-out to become black dwarfs.
B) The power source of white dwarfs is left-over heat.
C) White dwarfs are the coolest main sequence stars.
D) White dwarfs with mass greater than 1.4 times the Sun's mass cannot exist.
E) Stars with a mass like the Sun will end up as a white dwarf star.
F) The pressure that balances gravity in a white dwarf is called degenerate electron pressure.
G) White dwarfs are less dense than red giants.

Answer 1

Solution:

A,B,D,E,F

When a star runs out of fuel, it collapses inward on itself. White dwarfs contain approximately the mass of the sun but have roughly the radius of Earth. This makes them incredibly dense, beaten out only by neutron stars and black holes. The gravity on the surface of a white dwarf is 350,000 times that of gravity on Earth.

A white dwarf, also called a degenerate dwarf, is a stellar core remnant composed mostly of electron-degenerate

matter. A white dwarf is very dense: its mass is comparable to that of the Sun, while its volume is comparable to

that of Earth. A white dwarf's faint luminosity comes from the emission of stored thermal energy.