1. Galaxies

2. Bell Work – Good Morning!!
Get out the materials that you need and put your backpack in the back of the room.
If you were absent or need to make up a test see me.
Get a scrap sheet of paper from the front and do the following:
Write down the four layers of space that we learned.
Write one descriptive fact for each layer.

3. Spiral Galaxies
These are made up of parts including the disk, bulge, and arms.
Spiral arms contain gas, dust, and stars.
The arms rotate around the center of the galaxy.

4. Spiral Galaxy The bulge is the center of the galaxy.
Arms rotate around the bulge.
Most of the stars and dust are located here.
The disk is the entire galaxy, including all of its arms.

5. The Disk

6. Barred Spiral Galaxies
Same shape and composition as a spiral galaxy.
Have its arms connected or linked by a bar.

7. Elliptical Galaxies Shaped like spheres or eggs.
Have minimal dust and gas between the stars.
Stars are mostly old.
Smaller than spiral.

8. Irregular Galaxies Faint galaxies. Have no definite shape.
Smallest galaxies.
Have few stars.
Not common.

9. The Center of the Galaxy
Most galaxies, we predict, have a supermassive black hole at their center.
These holes are millions or billions times greater than the sun.
These are invisible; we have to infer that they are there.
Black holes pull in gas from nearby stars and give off very bright light.
This bright light is called a quasar, which means seeming like a star.

10. Our Home – The Milky Way
The sun and all of our planets are part of this galaxy.
We are on the edge of our galaxy.
Why is it named this?
Our galaxy appears hazy or milky in appearance because of its many stars.
It is a spiral galaxy.
It is more than 100,000 light years in diameter.
The bulge, or the area with most of the stars, is 26,000 light years from the sun.

11. The Milky Way

12. ABCD Review What type of galaxy has no definite shape? A. Elliptical
B. Spiral
C. Irregular

13. ABCD Review
What type of galaxy has no definite shape?
C. Irregular

14. ABCD Review What type of galaxy has something called an arm?
A. Elliptical
B. Spiral
C. Irregular

15. ABCD Review
What type of galaxy has something called an arm?
B. Spiral

16. ABCD Review What type of galaxy is pictured here? A. Elliptical
B. Spiral
C. Irregular

17. ABCD Review
What type of galaxy is pictured here?
A. Elliptical

18. ABCD Review What type of galaxy is pictured here? A. Elliptical
B. Spiral
C. Irregular

19. ABCD Review
What type of galaxy is pictured here?
B. Spiral