Life Cycle Of A Star

Question 1

Life cycle of a star detail

Answer 1

1) gravity due to mass contained within nebula causes it to collapse on itself, creating an increasing temperature protostar
2) when hydrogen fuel is used up, the star becomes a red giant, or supergiant
3) as the core of the supergiant cools, pressure forcing it outwards decreases and can no longer balance gravity

Question 2

Life cycle of a star

Answer 2

Nebula —> star —> red giant —> white dwarf —> black dwarf
Nebula —> massive star —> red supergiant —> super nova —> neutron star or black hole

Question 3

Our sun life cycle

Answer 3

1) Protostar
2) Fusion starts: Star is stable as thermal expansion forces from fusion balance the gravitational forces inwards. Fusion is hydrogen into helium
3) Red giant, fusing helium into heavier elements
4) Fusion stops, outer layers thrown off to leave white dwarf with planetary nebula around the thrown off layers
5) Cools to a black dwarf