1. Life Cycle of a Star A journey through it’s birth ‘til it’s death. By Anna, Damon, Shannon, Jon, and Patricia

2. Objectives How stars are formed How stars are formed What they are made up of What they are made up of What happens in the middle of life What happens in the middle of life Death of stars of different sizes Death of stars of different sizes

3. Birth of a Star Enormous clouds of gas and dust Enormous clouds of gas and dust Gravity tries to pull the materials together Gravity tries to pull the materials together A giant ball forms A giant ball forms Center of ball reaches 15 million degrees Center of ball reaches 15 million degrees

4. Nuclear fusion What is it? Enormous pressure at center of ball Enormous pressure at center of ball A plasma is created A plasma is created Nuclei crash together, then fuse Nuclei crash together, then fuse

5. Midlife of a Star Goal is to reach equilibrium Goal is to reach equilibrium Main Sequence: Main Sequence: 1. Basic Reactions 2. Hydrostatic equilibrium 3. Transport of energy

6. Hertzsprung-Russell (HR) Diagram

7. Death of a Star (depending on the mass of the star ) Sun-like stars (mass under 1.5 times the mass of the Sun) Sun-like stars (mass under 1.5 times the mass of the Sun) Huge Stars (mass between 1.5 and 3 times the mass of the sun) Huge Stars (mass between 1.5 and 3 times the mass of the sun) Giant Stars (mass over 3 times the mass of the Sun) Giant Stars (mass over 3 times the mass of the Sun)

8. Sun like stars (mass under 1.5 times the mass of the sun.) Become Red Giants After exhausting their hydrogen they burn Helium Become Red Giants After exhausting their hydrogen they burn Helium Outer Layers Ejected to Planetary Nebula Outer Layers Ejected to Planetary Nebula Leaving a dense white dwarf Leaving a dense white dwarf

9. White Dwarf 1.4 No fuel left to burn No fuel left to burn Radiates remaining Heat Radiates remaining Heat Eventually becomes a Black Dwarf if nothing else effects star Eventually becomes a Black Dwarf if nothing else effects star

10. Red Super Giant Rare due to short life span Rare due to short life span 2000 known in galaxy 2000 known in galaxy Made up of Helium, Hydrogen, and carbon Made up of Helium, Hydrogen, and carbon 8-10 times more massive then sun 8-10 times more massive then sun Extremely bright for hundred thousand to a million years Extremely bright for hundred thousand to a million years Implodes on itself ending in a type II supernova Implodes on itself ending in a type II supernova

11. Supernova Explosion of a star in space Explosion of a star in space Occurs when nuclear fuel is exhausted Occurs when nuclear fuel is exhausted No longer supported by release of nuclear energy No longer supported by release of nuclear energy A rare event in our galaxy (last being seen in 1604) A rare event in our galaxy (last being seen in 1604) Remnants can be seen for several weeks Remnants can be seen for several weeks Supernova end phase is a neutron star Supernova end phase is a neutron star

12. Neutron Star Final stage in death of a star Final stage in death of a star May appear in supernova remnants, as isolated objects or in binary systems May appear in supernova remnants, as isolated objects or in binary systems About 20km and 1.4 times more massive then our sun About 20km and 1.4 times more massive then our sun Posses gravitational field about 2 x 10^11 that of earth Posses gravitational field about 2 x 10^11 that of earth Escape velocity is about half the speed of light Escape velocity is about half the speed of light Are electrically neutral Are electrically neutral

13. Death of Huge stars (mass between 1.5 to 3 times that of our sun)

14. Giant Stars (mass over 3 times the mass of the sun.) Red Super Giants Red Super Giants Supernova Supernova Black holes Black holes

15. Summery Stars are made up of interstellar gasses, dust and gravity Stars are made up of interstellar gasses, dust and gravity The goal of a star is to reach an equilibrium The goal of a star is to reach an equilibrium What a star turns into when it dies depends on the size of the star whether it is smaller then our sun, the same size or larger then our sun What a star turns into when it dies depends on the size of the star whether it is smaller then our sun, the same size or larger then our sun