Review: Galaxies

What is the estimated number of galaxies in the visible universe?

• About 100 billion galaxies

• About 10 billion galaxies

How long does it take for our Sun to complete one galactic revolution?

• 25 billion years

• 250 million years

Tags

NGSS.HS-ESS1-4

What color are Population II stars typically?

• Red

• Yellowish

What color are Population I stars typically?

• White

• Blue

Where are Population II stars located?

• Disk

• Halo, bulge and globular clusters

Where are Population I stars mainly located?

• In the Halo

• In the Spiral Arms

What type of cluster are Population II stars associated with?

• Globular clusters

• Open clusters

This type of galaxy contains only old stars.

• irregular

• elliptical

This type of galaxy contains a mixture of all ages of stars.

• spiral

• elliptical

Identify the galaxy in the image.

• irregular

• spiral