1. Our Cosmos

2. Pleiades cluster

3. Star field 1

4. … stars take on a range of colours ...
Star field 2
… stars take on a range of colours ...

5. Classification of stars

6. Parallax method to determine distances to stars

7. Comparative sizes of stars

8. Hydrogen fusion

9. Pressure balance in a star
thermal pressure = force of gravity

10. Explanation for physical properties of stars
More massive star  higher thermal pressure  higher temperature  more luminous  faster fusion reactions  shorter lifetime

11. Hertzsprung-Russel diagram

12. Life history of the Sun

13. The Sun as a red giant

14. Red-giant Sun seen from Earth

15. Betelgeuse

16. Ring nebula

17. Cat’s eye nebula

18. Dumbbell nebula

19. Hourglass nebula

20. NGC 2440

21. Helix nebula
… notice there is a small star at the centre of each planetary nebula …

22. White dwarf
One basketball-full of white dwarf material weighs as much as an ocean liner

23. … an atom consists of mainly empty space ...
Model of an atom
… an atom consists of mainly empty space ...

24. Electron Degeneracy Pressure
Pauli Exclusion Principle: No two electrons can occupy the same position in space
Electrons are packed side by side in a white dwarf
This prevents it from collapsing any further

25. White dwarf stars

26. Chandrasekhar limit
The maximum mass of a white dwarf is 1.4 solar masses
Above this, even electron degeneracy pressure cannot counterbalance gravity
What is the fate of a star more massive than this?
S. Chandrasekhar ( )

27. Neutron star
One pinhead of neutron star material weighs as much as two of the biggest supertankers

28. Final stages of red giant

29. Birth of a neutron star and supernova remnant

30. A supernova is one of the most powerful explosions in the universe
Supernova 1987a
A supernova is one of the most powerful explosions in the universe

31. Supernova in a distant galaxy

32. Crab nebula and pulsar

33. Pulsars Discovered by Bell and Hewish in 1967
Stands for pulsating stars, since they emit regular pulses
Now known to be spinning neutron stars
Joycelyn Bell and Tony Hewish’s telescope consisted of 2048 wire aerials suspended on posts in a field

34. Why a pulsar emits regular pulses

35. Pulsar animation

36. Vela nebula and pulsar

37. 642 rotations/sec (fastest known pulsar)
The sounds of pulsars
PSR B
1.4 rotations/sec
Vela pulsar
11 rotations/sec
PSR B
642 rotations/sec (fastest known pulsar)

38. Cross-section of a neutron star