Section 15 P2 Spiral Galaxies vs. Elliptical Galaxies

Question 1

what kind of galaxy our Sun is in,

Answer 1

Spiral Galaxy AKA the Milky Way Galaxy

Question 2

what parts are possessed by a spiral galaxy: (4)

Answer 2

• a disc
• spiral arms
• bulge
• halo.

Question 3

If the bulge of a spiral galaxy is elongated, then this galaxy is a barred spiral galaxy. Agree that ____

Answer 3

we find examples of this

Question 4

4. Recognize which parts a spiral galaxy and an elliptical galaxy have in common and which ones they do not.

Answer 4

 Agree that ellipticals lack a disc and spiral arms.

Question 5

5. Identify the reason elliptical galaxies have a color between gold and red:

Answer 5

They are made of old and long-lived stars.

Question 6

Agree that it would be unlikely for a very heavy star to go supernova in an elliptical galaxy. This is because that kind of galaxy is only made of _______

Answer 6

• very old stars.

- Heavy stars die as supernova explosions when they are very young, so they are not found here.

Question 7

Recognize that _________. They do not all go around in the same direction in circles like stars in the disc of a spiral galaxy. They orbit in the same chaotic way as stars in the round parts of a spiral galaxy (bulge and halo).

Answer 7

stars orbit more randomly in elliptical galaxies

Question 8

9. Realize that if a galaxy is blue that means it has lots of recent star formation

Answer 8

(blue stars live short lives so they are new stars).