Understanding Galaxies

What holds a galaxy together?

• Gravity

• Magnetism

• Electricity

• Nuclear force

How many main types of galaxies are there according to the Hubble classification?

• Four

• Two

• Five

• Three

Which type of galaxy is featureless and spherical in shape?

• Spiral

• Elliptical

• Lenticular

• Irregular

What is a characteristic feature of a barred spiral galaxy?

• No defined shape

• Tightly wrapped arms

• A bar shape in the center

• A central bulge

What is the shape of an E0 elliptical galaxy?

• Highly elongated

• Perfectly spherical

• Irregular

• Disk-like

Which galaxy type is our Milky Way an example of?

• Irregular

• Barred spiral

• Regular spiral

• Elliptical

Which classification is used for regular spiral galaxies?

• S

• E

• I

• SB

What distinguishes an SBc galaxy from an SBa galaxy?

• SBc has a central bulge

• SBc has tightly woven arms

• SBc has loosely wrapped arms

• SBc is featureless

Which type of galaxy is not subdivided further?

• Elliptical

• Spiral

• Irregular

• Lenticular

What letter is used to classify lenticular galaxies?

• S

• SO

• E

• SB