Astronomy and Cosmology CHAPTER TEST

Which type of galaxy is characterized by a central bulge and spiral arms?

• Elliptical galaxy

• Spiral galaxy

• Irregular galaxy

• Lenticular galaxy

What is the approximate diameter of the Milky Way galaxy?

• 50,000 light-years

• 100,000 light-years

• 150,000 light-years

• 200,000 light-years

Which component makes up the majority of the Milky Way's visible mass?

• Dark matter

• Stars

• Interstellar gas

• Black holes

What is the name of the supermassive black hole at the center of our galaxy?

• Andromeda

• Sagittarius A*

• Centaurus A

• Alpha Centauri

How is the recession velocity (v) related to distance (d) in Hubble's Law?

• v=H0d

• v=H0/d

• v=d/H0

• v=H0d2

What is the primary shape of our Milky Way galaxy?

• Irregular

• Elliptical

• Barred spiral

• Spherical

What force counteracts the gravitational collapse of stars?

• Nuclear fusion pressure

• Electromagnetic force

• Dark energy

• Centripetal force

The Hubble constant (H₀) is measured in:

• Light-years

• Kilometers

• km/s/Mpc

• Parsecs

What percentage of the universe is believed to be dark energy?

• 45%

• 55%

• 70%

• 73%

The galactic bulge of the Milky Way contains primarily:

• Young, blue stars

• Old, red stars

• Nebulae

• Dark matter