Option D.1

Question 1

Nebula

Answer 1

A vast cloud of gas and dust

Question 2

Radiation pressure

Answer 2

The pressure exerted by photons, which result from the hydrogen to helium-4 fusion reaction

Question 3

Gas pressure

Answer 3

Pressure from the kinetic energy of the gas particles that make up the stars

Question 4

How does a star achieve a state of equilibrium?

Answer 4

The radiation pressure of photons and the gas pressure of fast moving particles balance out the inward force due to gravity

Question 5

Equation to find distance in AU to a star with a parallax angle p

Answer 5

d(AU) = 1AU/tan(p)

Question 6

Luminosity

Answer 6

The rate at which a star radiates energy

Question 7

Apparent brightness

Answer 7

The power of a star’s radiation received by an observe per unit area

Question 8

Planet

Answer 8

A body that orbits the sun or another star, is massive enough so that its self-gravity makes it more or less spherical, and has cleared its orbit of other bodies