Main stages in a massive star’s life cycle 1. Nebula (birth) 2. Blue giant 3. Super red giant

1. Main stages in a massive star’s life cycle 1. Nebula (birth) 2. Blue giant 3. Super red giant 4. Supernova 5. Neutron star or Black hole

2. Main stages in a Sun-like star’s life cycle 1. Nebula (birth) 2. Blue star 3. Red giant 4. Planetary nebula 5. White dwarf

4. Birth of the Solar System (according to the Nebular Theory) 1. Gravitational collapse in a nebula (caused shockwaves from a nearby supernova) 2. Nebula begins to spin and flatten (forming an accretion disk) 3. Center of accretion disk becomes a protostar 4. Protostar gathers more gas and dust 5. Protoplanets (planetissimals) form in the accretion disk 6. Protoplanets form by accretion (collisions, fusions, etc.) 7. Protostar reaches critical mass (enough heat and pressure to begin nuclear fusion) 8. Stellar wind sweeps away excess gas and dust (protoplanets remaining become planets)

6. Layers and properties of the Sun 1. Core – source of energy (generated by nuclear fusion) 2. Radiative zone – nuclear energy moves slowly outward from the core through the rad zone (takes more than 170,000 yrs to get past this zone) 3. Convective zone – energy continues to move outward via convection of hot and cool gases in this zone 4. Photosphere – visible surface of the Sun (where the Sun’s energy becomes sunlight and escapes the Sun to move throughout space); layers above the photosphere are considered part of the Solar Atmosphere 5. Chromosphere – layer of gases surrounding the Sun; gives the Sun its yellowish color 6. Corona – stream of plasma moving out to space; the corona extends and becomes the stellar wind

9. Solar Events (these affects the amount of radiation we receive from the Sun and hence, our daily life from photosynthesis to communications) 1. Sun spots – dark areas of cooler gas in the Sun’s photsphere; number of spots is cyclical (there’s a minimum and a maximum throughout a year); the cycle is affected by the Sun’s magnetic field (buildup of magnetic energy equals appearance of spots; release of magnetic energy equals decay or disappearance of spots) 2. Solar flare – sudden brightening over the Sun’s surface caused by a massive release of solar energy 3. Coronal mass ejections – sudden and massive ejection of plasma into space (like an exceptionally huge blast of stellar wind) 4. Prominence – sudden release of plasma as magnetic lines of force snap Excellent link for study

10. Sunspots

11. Prominence

12. Solar flare

13. Prominence Coronal Mass Ejection