White Dwarfs & Planetary Nebulae

Phil Plait discusses the fate of low mass stars, focusing on white dwarfs and planetary nebulae. White dwarfs are dense, hot remnants of stars, while planetary nebulae are beautiful, short-lived structures formed by expelled gas illuminated by the white dwarf. The video explores the formation, characteristics, and diverse shapes of these nebulae, influenced by factors like binary stars and swallowed planets. The sun is unlikely to form a planetary nebula, but more massive stars do. The episode concludes with a look at the sun's quiet end and a teaser for the next topic on massive star explosions.

What happens to low mass stars like the sun after they exhaust their nuclear fuel?

• They become black holes.

• They explode as supernovae.

• They become white dwarfs.

• They turn into neutron stars.

What force supports a white dwarf against gravitational collapse?

• Magnetic pressure

• Electron degeneracy pressure

• Nuclear fusion pressure

• Thermal pressure

Why are white dwarfs so dense?

• They have a large volume.

• Their electrons are tightly packed.

• They are composed of heavy elements.

• They have a strong magnetic field.

What is a planetary nebula?

• A type of galaxy

• A cluster of stars

• A type of planet

• A cloud of gas illuminated by a white dwarf

Who first discovered planetary nebulae?

• Charles Messier

• Isaac Newton

• Edwin Hubble

• Galileo Galilei

What can cause the diverse shapes of planetary nebulae?

• The presence of binary stars

• The star's magnetic field

• The star's age

• The star's initial mass

How might planets influence the shape of a planetary nebula?

• By changing the star's temperature

• By spinning up the star's rotation

• By altering the star's magnetic field

• By increasing the star's mass

What element primarily causes the green glow in planetary nebulae?

• Helium

• Oxygen

• Nitrogen

• Hydrogen

Why might our sun not form a visible planetary nebula?

• It lacks sufficient mass and energy.

• It will be consumed by a nearby star.

• It will explode as a supernova.

• It will become a black hole instead.

What can the study of planetary nebulae reveal about stars?

• Their magnetic fields

• Their chemical composition

• Their evolutionary history

• Their gravitational waves