This question is about orbital mechanics and stellar evolution.
Compare the orbital path and speed of a comet with those of a planet as they orbit the Sun. State two differences.
The diagram shows a cross-section of a stable main-sequence star.
Point P P\,P is located inside the star, within its outer layers.
State the direction of the gravitational force Fg F_g\,Fg acting on the matter at point PPP.
State the direction of the outward radiation pressure force Fp F_p\,Fp acting on the matter at point P P\,P due to nuclear fusion in the core.
Explain why the size of the star does not change. Write about force Fg F_g\,Fg and force Fp F_p\,Fp in your answer.
Complete the sentences about the life cycle of a star with a mass similar to our Sun using the words below. Each word can be used once, more than once, or not at all.
- black dwarf
- black hole
- nebula
- neutron star
- red giant
- supernova
- white dwarf
Towards the end of its main-sequence lifetime, a low-mass star runs out of hydrogen fuel and expands.
The star becomes a ............................................................. .
The outer layers of gas are eventually ejected into space, leaving behind a hot, dense core called a ............................................................. .
Over billions of years, this core cools down completely to end its life as a cold, dark ............................................................. .