1. The Sun
NASA photograph, Skylab, 10 December 1973

2. Sun Facts Mass 1.989 × 1030 kg (99.9% of Solar system)
Diameter 1.39 million km (109 times Earth)
Surface Temperature 6000K
Energy Output × 1036 W

3. Spectrum of the Sun
Source: McMath-Pierce Solar Observatories

4. Layers
Source: Gribbin & Gribbin, From Here to Infinity, 2008, p. 68

5. Sun’s corona
Source: Koen van Gorp

6. Density
Source: Arny & Schneider, Explorations, p.314.

7. Net reaction: 4 p+  4He + 2 e+ + 2 n + 2 g
Fusion in the Core
Source: Seeds, Horizons: Exploring the Universe
Net reaction: 4 p+  4He + 2 e+ + 2 n + 2 g

8. Surface Granules convection cells Around 1000 km across
Typically last about 10 minutes
Source: NOAO

9. Sunspots Relatively cool surface region
Associated with magnetic disruptions
Source: Vacuum Tower Telescope, National Solar Observatory

10. Sun’s Magnetic Field Sun’s interior (plasma) conducts electric current
Sun rotates: faster at equator than poles

11. Gas circulation
Source: Solar and Heliospheric Observatory (SOHO)

12. Solar Cycle
Source: Solar and Heliospheric Observatory (SOHO)

13. Solar cycle Magnetic field reverses every ~11 yr
Source: Gribbin & Gribbin, From Here to Infinity, 2008, p. 72