Bing Quiz Archive
White Dwarfs Quiz Archive
Archived edition • Originally published August 20, 2026
Test your knowledge of white dwarfs, the compact stellar remnants left behind by many stars, including their formation, extreme density, cooling, structure, and role in stellar explosions.
⚪✨🔭 White Dwarfs Quiz • 10 Questions • ⏱️ 150 Seconds
⚪ Stellar Remnants
⚛️ Degenerate Matter
⭐ Star Evolution
💥 Supernovae
⏱️ Time: 150s
✅ Answered: 0/10
This August 20 archive remains fully playable. Answer choices and their A–D labels reshuffle whenever the page loads, and the 150-second timer begins after your first answer.
1
What is a white dwarf?
Correct answer: A dense stellar remnant left after a Sun-like star sheds its outer layers. White dwarfs are the compact exposed cores left by many low- and intermediate-mass stars after they exhaust their core fuel and lose their outer layers.They no longer sustain ordinary core fusion, but newly formed white dwarfs remain extremely hot.
2
A typical white dwarf is roughly comparable in size to which object?
Correct answer: Earth. A white dwarf can contain a large fraction of the Sun's mass while being packed into a sphere roughly comparable to Earth in size.That combination of substantial mass and small volume gives white dwarfs extraordinarily high densities and surface gravity.
3
What mainly supports a white dwarf against further gravitational collapse?
Correct answer: Electron degeneracy pressure. Quantum mechanics prevents electrons from all being squeezed into the same states, creating degeneracy pressure that can resist the white dwarf's gravity.This support does not depend on ordinary thermal gas pressure from active nuclear fusion.
4
What is the Sun expected to become after its red-giant phase and the loss of its outer layers?
Correct answer: A white dwarf. The Sun is not massive enough to end its life as a neutron star or black hole. After evolving through its giant stages and shedding its outer material, its hot core will remain as a white dwarf.The expelled outer layers can briefly form a planetary nebula around the exposed core.
5
Why does an isolated white dwarf generally become dimmer over very long periods of time?
Correct answer: It radiates away stored heat without sustained core fusion replacing that energy. A white dwarf begins extremely hot but has no long-term core fusion source like a main-sequence star, so it gradually cools and fades.The cooling process is extremely slow and can continue for billions of years.
6
Approximately what is the Chandrasekhar limit for a white dwarf?
Correct answer: About 1.4 times the Sun's mass. The Chandrasekhar limit is the approximate maximum mass that can be supported as a white dwarf by electron degeneracy pressure under the usual model.White dwarfs pushed toward instability can participate in explosive events, depending on the system and composition.
7
Which famous star is a white dwarf companion to the bright star Sirius A?
Correct answer: Sirius B. Sirius B is the compact white dwarf companion of Sirius A, the brightest star in Earth's night sky.Despite being very hot, Sirius B is faint compared with Sirius A because its emitting surface is so small.
8
For ordinary white dwarfs, what generally happens to their radius as their mass increases?
Correct answer: The radius generally becomes smaller. White dwarfs have an unusual mass-radius relationship: adding mass increases the required degeneracy pressure and typically makes the star more compact.This is very different from the intuitive expectation that a more massive object should simply be larger.
9
What can happen inside a white dwarf as it cools over extremely long timescales?
Correct answer: Part of its dense interior can crystallize. As a white dwarf cools, the ions in its dense interior can settle into an ordered crystalline structure.ESA's Gaia data have provided observational evidence for crystallization in populations of cooling white dwarfs.
10
Which statement best describes the connection between white dwarfs and Type Ia supernovae?
Correct answer: They involve a white dwarf in a binary system becoming thermonuclearly unstable, such as through mass transfer or a white-dwarf merger. Type Ia supernovae are thermonuclear explosions associated with white dwarfs in binary systems; astronomers study more than one progenitor pathway.These explosions are especially important in astronomy because their brightness can be used to help measure cosmic distances.