Types of Stars

Question 1

Main sequence on Hertzsprung-Russell diagram

Answer 1

Diagonal belt from cool +15 (0.1x mass of Sun) to hot -5 (30x)

Question 2

Giants on Hertzsprung-Russell diagram

Answer 2

Magnitudes +2 to -2, larger but cooler than the Sun

Question 3

Supergiants on Hertzsprung-Russell diagram

Answer 3

Magnitudes -5 to -10, very large and bright

Question 4

White dwarf stars on Hertzsprung-Russell diagram

Answer 4

Magnitudes +15 to + 10, hotter but much smaller than the Sun

Question 5

Formation of a star

Answer 5

Dust and gas clouds contract -> protostar (GPE to Ke heat) -> fusion -> photosphere as a star

Question 6

How does a main sequence star maintain its structure?

Answer 6

Internal equilibrium of gravity and radiation pressure (H fusing to He)

Question 7

Formation of a red giant

Answer 7

H runs out -> core collapsed -> outer layers expand and cool

Question 8

How do red giants maintain their structure?

Answer 8

Hot collapsed core produces H fusing shell. If hot enough He fused

Question 9

Length of red giant phase compared to main sequence

Answer 9

1/5

Question 10

After red giant phase

Answer 10

< 8 solar masses -> white dwarf

Larger -> swells to supergiant -> supernova

Question 11

Forming a white dwarf

Answer 11

Core fusion stops -> contracts and outer layer thrown off (planetary nebulae) producing up to Fe -> (<1.4 solar masses)

Question 12

Journey of the Dun

Answer 12

Protostar, main sequence, red giant, collapsing, white dwarf

Question 13

How do white dwarfs remain stable?

Answer 13

Force of gravity = electron repulsion