Galaxy Class

Galaxies

Open Ended

Have you ever used a telescope to look at the night sky?

If so, what did you see?

Have you ever visited an observatory?

If not, what would you look at if given the opportunity to look through a telescope? A planet? The moon? A star? A galaxy?

Discussion Posts

None so far . . .

Multiple Choice

What force causes a galaxy to form?

• Gravity

• Nuclear Fusion

• Kinetic Energy (Movement)

• Thermal Energy (Heat)

Multiple Choice

What is the shape of most galaxies?

• Elliptical

• Spiral

• Irregular

Multiple Choice

How does dark matter affect galaxies?

• it causes them to be hotter than expected

• it causes them to spin faster than expected

• it causes them to not be as bright as expected

Multiple Choice

What shape is common for older galaxies?

• spiral

• elliptical

• irregular

• barred spiral

Multiple Choice

What color is the most common in younger galaxies?

• red

• blue

• green

• brown

Multiple Choice

What is the classification for a very clearly round elliptical galaxy?

• S5

• S0

• Sb0

• E0

• E5

Multiple Choice

What type of galaxy is the milky way?

• Spiral

• Barred Spiral

• Elliptical

• Irregular

Multiple Choice

What usually causes an irregular galaxy?

• a surge in dark matter

• a nearby supernova explosion

• a collision with another galaxy

Multiple Choice

What is a satellite galaxy?

• a cluster of galaxies that bend light

• two galaxies in close proximity

• a small galaxy orbiting a larger galaxy

Multiple Choice

What type of galaxies are able to bend light?

• a gravity lens

• a satellite galaxy

• a local group

Galaxy Formation

• Gas clouds clump together due to the gravitational pull of matter
• As the matter gets drawn together, it starts to spiral downwards into the central mass
• The center becomes squeezed typically until a black hole forms
• Over time, the galaxy might slowly stop spinning and become elliptical
• Galaxies may collide with other galaxies to form different shapes

Dark Matter

A type of physical matter that does not release any detectable light or shape. 

We see the gravitational effect of dark matter causing galaxies to spin faster than is possible given their visible matter.

Galaxy Classification

Galaxies are classified by their shapes and how distinct those shapes are:

• Elliptical - E
• Spiral - S
• Barred Spiral - SB I
• rregular - I

Galaxy Clusters

* Satellite Galaxies - Smaller galaxies that orbit around larger galaxies and are trapped in the larger galaxies gravitational pull

* Local Group - the galaxies in close proximity to our galaxy 

* Gravity Lens - a dense collection of galaxies with enough gravity to bend space

Open Ended

Do you have any questions about galaxies?

-Do you know how they are formed?

- Do you know how they are classified?

- Do you know how galaxies are grouped?

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Any Questions From the videos?