1. The Universe 8.8A

2. The Universe The universe is all space and everything in it

3. Components of the Universe There are lots of parts of the universe: – Stars – Nebulae – Black Holes – Galaxies And so much more!

4. Stars Stars are large balls of gas that create their own energy by fusing hydrogen atoms to create helium – The energy created by fusing hydrogen atoms emits light and heat

5. Stars Stars are all different sizes and are made up of different elements

6. Stars Binary Star: Stars that revolve around each other, they look like they are blinking

7. Classifying Stars Stars are classified by three main characteristics: 1.Size 2.Brightness (luminosity) 3.Temperature

8. Classifying Stars Size Our sun is a medium size star (letter G below) There are stars in the universe large enough to fill our solar system

9. Classifying Stars Temperature Temperature is determined by color – Blue: Hottest (20,000-50,000*C) – White (10,000*C) – Yellow (6,000*C) – Red-Orange (4,000-5,000*C) – Red: Least Hot (3,000*C) Blue  Red

10. Classifying Stars Brightness Brightness depends on the size and temperature of a star Brightness of a star is described in two ways – Apparent Magnitude: Brightness seen from earth – Absolute magnitude: Real brightness of a star from a standard distance

11. Hertz-Russell Diagram Nickname: H-R Diagram How does it help classify Stars? – Graphs the two most important characteristics of stars: Absolute magnitude (brightness) and Temperature

12. Hertz-Russell Diagram Main Sequence: 90 % of all stars, it is the diagonal band in the diagram

13. Galaxy Galaxies are made up of millions of stars, gases, and dust

14. Galaxy Galaxies are held together by gravity

15. Galaxy There are 4 different types of galaxies that are classified by their shape. – Elliptical – Spiral – Lenticular – Irregular

16. Draw these next to the pictures in your box (not in the giant white space that is for notes)

17. Elliptical Galaxy Looks like a flattened ball Characteristics: – Contain billions of stars – Little gas and dust between the stars – New stars rarely form, mainly old stars in these galaxies

18. Spiral Galaxy Shaped like they have arms spiraled outwards (pin wheel) This is the type of galaxy we live in This is the type of galaxy we live in

19. Lenticular Galaxy Galaxy with a central bulge or bar in the middle It might also have small arms

20. Irregular Galaxy No specific shape to the galaxy Disorganized shape

21. Black Holes Large objects that form dense gravity wells Their gravitational pull is so strong, light cannot escape it (hence why they are dark!)

22. Black Holes How can we see black holes: – We can’t – We observe them by looking at the light and energy being sucked in

23. Black Holes Black holes have no volume, but infinite density! Videos: http://www.youtube.com/watch?v=3pAnRKD 4raY – Pre AP http://www.youtube.com/watch?v=3pAnRKD 4raY http://www.youtube.com/watch?v=kfiU4ioZv PI http://www.youtube.com/watch?v=kfiU4ioZv PI