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What is an example of each type of galaxy?

Spiral - Elliptical - Irregular• Milky Way

• Andromeda• M87 • Large

Magnellanic Cloud

Add examples to your Princeton Notes!

Elliptical

Irregular

Spiral

Galaxy

Large groups of stars, dust, and gas

Come in a variety of sizes and shapes

Can have more than a trillion stars

Can estimate how many sun-sized stars the galaxy may have by studying the size and brightness of the galaxy

Spiral Galaxy

Bulge at the center and spiral arms

Spiral arms are made up of gas, dust, and new stars

Milky Way Galaxy

Spiral Galaxy

5. What is an elliptical galaxy?

1/3 of all galaxies

Described as a “massive blob” of stars

Generally looks like a sphere

Has a very bright center

Very little gas and dust

Contains mostly old stars

6. What is an irregular galaxy?

Irregular shaped galaxy

“cloud-like”

ADD TO NOTES:

¼ of all galaxies

Contains large amount of gas and dust

A lot of star formation occurs within

10. What are quasars?

Among the most distant objects in space

“Star-like” sources of light

Among the most powerful energy sources in the Universe

May be caused by massive black holes in the cores of distant galaxies

Quasars

Fun Fact: Because they are so far away, they are found using radio waves

How the Universe Works: Galaxies

Nebula Large clouds of gas and dust

Some glow

Some absorb light and hide stars

Some reflect starlight

Some are regions where new stars form

Spiral galaxies usually contain nebulas

Elliptical galaxies contain very few nebulas

EX: Crab Nebula

In the Taurus constellation

Not visible to unaided eyeAt center is the Crab pulsar

Globular Cluster Groups of older stars

Looks like a ball

Up to 1 million stars

Located in a spherical halo that surround spiral galaxies

Also commonly located near giant elliptical galaxies

EX: Omega Centauri Cluster

Located in Centaurus constellation

Largest and brightest globular cluster in Milky Way Galaxy

10,000,000 stars10 - 12 billion years old

11 Visible to unaided eye

Open Clusters

Groups of closely grouped stars

Usually located along the spiral disk of a galaxy

Newly formed open clusters have many bright blue stars

Few hundred to a few thousand stars

EX: The Wild Duck Cluster (M11)

Located in Scutum constellation