ASP MCQ 3

Question 1

Which type of galaxy is characterized by a central bulge, spiral arms, and a disk of stars and gas?

Accepted Answer

Spiral

Answer

Spiral galaxies feature a central bulge surrounded by a flat disk with curved spiral arms containing young stars, gas, and dust.

Question 2

What is the Chandrasekhar limit in stellar astrophysics?

Accepted Answer

The maximum mass of a white dwarf (~1.4 solar masses)

Answer

The Chandrasekhar limit (~1.4 solar masses) is the maximum mass a white dwarf can have before electron degeneracy pressure can no longer support it.

Question 3

Which force primarily drives the formation of stars from interstellar gas clouds?

Accepted Answer

Gravitational force

Answer

Gravity causes regions of a gas cloud to collapse inward; as density and temperature rise, nuclear fusion eventually ignites a new star.

Question 4

What does the cosmic microwave background (CMB) radiation represent?

Accepted Answer

Afterglow light from the Big Bang about 380,000 years after it occurred

Answer

The CMB is the relic thermal radiation from when the universe cooled enough for atoms to form, releasing photons that now permeate all of space.

Question 5

What unit is commonly used to measure distances within our solar system?

Accepted Answer

Astronomical unit (AU)

Answer

One astronomical unit (AU) equals the average Earth-Sun distance (~150 million km) and is the standard measure for intra-solar-system distances.

ASP - Astronomical Society of the Pacific Exam Practice Test