PHYSICS - Astrophysics - Lifecycle of a star

The video explains the life cycle of stars, starting from their formation in stellar nebulas. Stars form when dust and gas spiral together under gravity, eventually becoming hot enough for nuclear fusion. This leads to the main sequence phase, where stars remain stable for millions to billions of years. Smaller stars, like our sun, eventually become red giants, then white dwarfs, and finally black dwarfs. Massive stars, however, become super red giants and may end in a supernova, forming either a neutron star or a black hole. The video highlights that all elements heavier than iron are formed in supernovae, emphasizing that we are made of stardust.

What is the initial stage in the formation of a star?

• A red giant

• A stellar nebula

• A black hole

• A neutron star

During which phase does a star like our sun expand and engulf the inner planets?

• Main sequence star

• White dwarf

• Protostar

• Red giant

What is the final stage of a smaller star's life cycle?

• Neutron star

• Black hole

• Black dwarf

• Supernova

What event marks the end of a massive star's life cycle?

• Cooling into a black dwarf

• A supernova explosion

• Formation of a protostar

• Becoming a red giant

What can form if the mass of a neutron star is high enough?

• A stellar nebula

• A red giant

• A black hole

• A white dwarf