Astronomy Stars and Stellar Evolution 4

Question 1

What is a neutron star primarily composed of?

Accepted Answer

Densely packed neutrons

Answer

A neutron star is crushed so tightly that protons and electrons merge into neutrons.

Question 2

A rapidly spinning neutron star that emits beams of radiation is called a what?

Accepted Answer

Pulsar

Answer

Pulsars are rotating neutron stars whose beams sweep past Earth like a lighthouse.

Question 3

Cepheid variable stars are important because their pulsation period relates to their what?

Accepted Answer

Luminosity

Answer

The period-luminosity relation lets Cepheids serve as cosmic distance markers.

Question 4

What is the boundary around a black hole beyond which nothing can escape?

Accepted Answer

The event horizon

Answer

The event horizon marks the point where escape velocity exceeds the speed of light.

Question 5

In a binary system, what can cause a white dwarf to undergo a Type Ia supernova?

Accepted Answer

Accreting enough matter to exceed the Chandrasekhar limit

Answer

A white dwarf pulling mass from a companion can exceed its stability limit and detonate.

Astronomy Practice Test