The life cycle of stars

What determines the life cycle of a star?

The mass of the star determines its life cycle.

What is the first stage in the life cycle of a star?

A nebula, a cloud of gas and dust, is the first stage.

How does a protostar form?

A protostar forms when gravity pulls gas and dust together, increasing pressure and temperature.

What process occurs in a main sequence star?

Nuclear fusion of hydrogen into helium occurs in a main sequence star.

What is the main energy source for a star during its main sequence stage?

The fusion of hydrogen nuclei into helium releases energy.

What happens to a star like the Sun after the main sequence stage?

It expands into a red giant.

What happens to massive stars after the main sequence stage?

They expand into red supergiants.

What is the fate of a red giant?

It sheds its outer layers to form a planetary nebula, leaving behind a white dwarf.

What happens to a red supergiant?

It undergoes a supernova explosion

What is left behind after a supernova explosion?

A neutron star or a black hole, depending on the mass of the core.

What is a white dwarf?

A small, dense remnant of a red giant with no nuclear fusion.

How is a black hole formed?

A black hole forms when a massive star's core collapses under gravity after a supernova.

What is a neutron star?

A dense core made mostly of neutrons, left after a supernova.

Why does a star remain stable during its main sequence?

The outward pressure from nuclear fusion balances the inward pull of gravity.

What role does gravity play in the life cycle of a star?

Gravity causes the initial collapse of gas and dust and holds the star together during its lifetime.