ASP Stellar Astronomy and Star Life Cycles 3

Question 1

What is the Kelvin-Helmholtz mechanism?

Accepted Answer

Gravitational contraction that converts potential energy into thermal energy in stars

Answer

The process of nuclear fusion in stellar cores

Answer

A type of stellar flare activity

Answer

The magnetic field reversal cycle of stars

Question 2

What is a T Tauri star?

Accepted Answer

A young pre-main-sequence star still contracting toward the main sequence

Answer

A star at the end of its life shedding outer layers

Answer

A type of variable star in the instability strip

Answer

A white dwarf accreting material

Question 3

What is the Hayashi track on the H-R diagram?

Accepted Answer

The nearly vertical evolutionary path of a protostar contracting toward the main sequence

Answer

The path of a star during its red giant phase

Answer

The path of a star from main sequence to white dwarf

Answer

The track of massive stars approaching supernova

Question 4

What determines where a star will fall on the main sequence?

Accepted Answer

Its mass

Answer

Its age

Answer

Its rotation speed

Answer

Its chemical composition

Question 5

What is an asymptotic giant branch (AGB) star?

Accepted Answer

A late-stage giant star fusing helium in a shell around an inert carbon-oxygen core

Answer

A rapidly rotating giant star

Answer

A binary star system at the giant phase

Answer

A star with a planetary companion at the giant stage

Question 6

What is the proton-proton chain reaction?

Accepted Answer

The primary nuclear fusion sequence in the Sun converting four protons into a helium nucleus

Answer

A fusion chain that combines helium into carbon

Answer

A fission reaction breaking heavy elements into lighter ones

Answer

The process by which neutron stars emit radiation