Fall 2023 Astro 150 Final Review Part 1

If the Sun were the size of a basketball and placed on this desk, how far away would Alpha Centauri be?

• Howe Hall

• Ankeny

• Not even in this state

• Sioux City

Which of these is NOT one of Kepler's laws of planetary motion?

• Planets orbit the sun in elliptical orbits

• An object at rest stays at rest unless perturbed by an outside force

• Planets move faster when closer to the sun

• P² = a³

What supports a star from collapsing under its own gravity?

• Outward radiation pressure.

• Pauli exclusion principle.

• Centrifugal force due to rotation.

• Support from magnetic field lines.

Star 1 has a brightness of 4*10¹⁰ erg/s/cm² . Star 2 is twice as far away with the same luminosity. What is its brightness, also in erg/s/cm²?

• 1*10¹⁰

• 4*10⁵

• 2*10¹⁰

• 2*10⁵

You observe two stars. Star #1 has a temperature 10x that of Star #2, but Star #1 is 1/10th the size of Star #2. How does the luminosity of Star #1 compare to Star #2?

• L1/L2 = 10²

• L1/L2 = 10^-2

• L1/L2 = 10⁴

• L1/L2 = 10^-4

What is the total amount of time our Sun will spend on the Main Sequence?

• ~1 billion years

• ~5 billion years

• ~10 billion years

• ~13.8 billion years

What kind of object will our Sun eventually turn into?

• A brown dwarf

• A white dwarf

• A neutron star

• A black hole

• White Dwarf

• Red Giant

• Neither

• Not enough information

What is a radio interferometer?

• An irritating radio signal that distorts astronomical radio data

• Such a device does not exist

• A device radio astronomers use to filter out earth-based radio broadcasts

• Several radio telescopes working together to improve resolution

What is NOT an advantage of a GROUND BASED telescope?

• You can see any wavelength

• They're cheaper to construct

• There's much fewer limitations on the size of the telescope

• If something goes wrong, it's easier to fix