1. Stars Which includes the Sun? Cosmology- the study of cosmos

2. Constellations Originated from Greek Mythology A group of stars as seen from Earth

3. The life cycle stages depend upon mass The length of time for each cycle also depends on mass- More mass shorter lifespan

4. Life Cycle of a smaller star

5. Life Cycle of a Star Nebula- (infancy) clouds of dust and gases being pulled together by gravity As the matter gets pulled together by gravity it starts to spin- forming a Proto-star The "Pillars of Creation" from the Eagle Nebula

6. Proto-star Temperature increases due to friction Nuclear Fusion marks start of main sequence (H+H->He + energy) THE BIRTH of a STAR

7. Fuel of stars= hydrogen through fusion form larger elements such as helium Our Sun’s mass is 75% H, 25% He- -this tell us what??

8. Main Sequence Star is at equilibrium: The forces of fusion (from the core) and the force of gravity (from the outside) create a state of balance

9. Red Giant is a large aged reddish star Not enough Hydrogen gas to support fusion so outer layers expand As the material pushes outwards, a ring of gas forms around the carbon Star collapses due to pressure from outer layers and no pressure from fusion This is what will happen to our Sun

10. Planetary Nebula After 100 mill years the temperature starts to cool due to high levels of carbon and oxygen Glowing gas due to UV radiation from core Gases dissipate into space

11. White dwarf All fuel collapses leaving a much smaller but extremely dense object After several BILLION years it becomes a black dwarf (all energy spent)

12. SUPER RED GIANT Same as a red giant but much more mass

13. If star is more massive then a star like our sun… Supernova occurs- huge explosion then becomes a neutron star or black hole depending on mass

14. Neutron Star After a supernova two possible outcomes - neutron star or black hole Neutron Stars- forms if smaller than 10-25 x the size of the sun –very dense but small neutron star can sometimes be detected as pulsars

15. Black hole Black Hole- If larger than about 15x sun –Due to large quantities of mass- –Gravity pulls inwards not letting anything escape –no light –But can be detected by gravitational pull on near by objects

17. QUESTIONS…. 1.What is the difference between the life cycle of a star similar to our Sun and the life cycle of a star three times the size of the Sun? 2.There are three final outcomes for the demise of a star: black hole, neutron star, white dwarf- what is the difference? 3.Will our Sun end up as a black hole? Explain your answer. 4.Will a Red giant undergo a supernova? 5.What is the main fuel of the Sun?