Chapter 5

Question 1

Which force allows GMC to become stars?

Answer 1

Gravity

Question 2

How many years does a GMC collapse take?

Answer 2

Approx 6000 years

Question 3

What other factors slow a GMC collapse?

Answer 3

Gas pressure, rotation of cloud, magnetic field, turbulance

Question 4

What 3 factors can begin GMC collapse?

Answer 4

Supernova, density waves, or stellar winds/mass ejections

Question 5

What phase must a star undergo before it initiates steady nuclear burning?

Answer 5

The T-Tauri phase

Question 6

What does the end of the T-Tauri phase indicate?

Answer 6

The birth of a new star

Question 7

What does ZAMS mean?

Answer 7

Zero-Age Main Sequence stars

Question 8

Under what condition can material in the disk fall inward

Answer 8

Only if they lose angular (through mass loss, turblance, interaction with magnetic field etc.)

Question 9

What are the 5 components of the protostar-disk system

Answer 9

Protostar, disk, spin axis, jet, inflowing envelope

Question 10

What is the Spin-up Problem?

Answer 10

The expected final velocity of the star is 10^5 times the observed velocity