1. Stars Evening Classes Week Three The Sun and Stars Presented by Oisín Creaner

2. Corona Convective Zone Radiative Zone Photosphere Core Interior of the Sun

3. The Sun

4. Sunspots

5. The Sun

6. Causes of sunspots

7. Stellar Classes

8. Emission & Absorption Spectra

9. Binary Stars - the Doppler Effect!

10. Doppler Effect

11. Spectral Class of some well known stars

12. MASS-LUMINOSITY RELATIONSHIP L = M 35 01 35 = 01 x 01 x 01 x 01 = 1/3,000 th 2 35 = 2 x 2 x 2 x 2 = 1131 100 35 = 100 x 100 x 100 x 100 = 10 million.

13. Stars Evening Classes Week Three Presented by Oisín Creaner

14. Hydrostatic Equilibrium

15. Hydrostatic Equilibrium The collapsing nebula’s core is squeezed by gravity

16. Hydrostatic Equilibrium It reaches 10 million degrees.

17. P P P Extent of electro- magnetic force (repulsive) Extent of strong nuclear force (attractive)

18. Hydrostatic Equilibrium Balance between gravitation & thermal expansion

19. Core Helium Enrichment

20. Helium Core Hydrogen fusing shell

21. Helium Core Hydrogen fusing shell

22. Helium Core Hydrogen Envelope

23. A Star’s Life - Death After the main sequence

25. Supernovae

26. The Sun in 5 billion years

27. Planetary Nebulae

28. White Dwarfs

29. Thank You www.astronomy.ie/handouts www.stellarium.org Useful websites