4.8.1.2 The Life Cyle Of A Star

Question 1

What is the life cycle of a low mass star?

Answer 1

1. Nebula- collection of dust, gas and rock
2. Protostar-gravity pulls particles together. As they move onwards GPE turns to heat and protostar is formed.
3. Main sequence-a stable star
4. Red Giant- increase in size because hydrogen and helium ran out
5. The death-red giant will collapse Uber its own gravity to a dense white dwarf
6. The death- from white dwarf it cooled forming a black dwarf

Question 2

What is the life cycle of a high mass star?

Answer 2

1. Nebula- collection of dust, gas and rock
2. Protostar-gravity pulls particles together. As they move onwards GPE turns to heat and protostar is formed.
3. Main sequence-a stable star
4. Red supergiant- 4x bigger than sun means a red supergiant
5. The death-shrink and then explode releasing massive amounts of energy, dust and gas(supernova)
   After this the start could either:
   -6a. The death- remaining core turn to a Neuton star
   -6b. The death- if the star is big enough it could become a BLACK HOLE

Question 3

Why is our sun believe to be a second generation star?

Answer 3

It contains some heavier elements that would have been release by a supernova and thrown when the star exploded.
The heavier elements indicated they might have been made from remains of previous starts

Question 4

What “generation star” is our sun

Answer 4

Second generation star

Question 5

Describe how the fusion reactions in the sun?

Answer 5

1 1 2
H + H —> H - isotope of hydrogen
1 1 1

2 1 3
H + H —> He - isotope of helium
1 1 2

3 3 4 1
H + H —> He + 2 H
2 2 2 1

The sun fuses hydrogen nuclei together to make helium nuclei, and a huge amount of energy is also released.