Astronomy Stars and Stellar Evolution 2

Question 1

What is the primary source of energy in a main-sequence star like the Sun?

Accepted Answer

Nuclear fusion of hydrogen into helium

Answer

Gravitational collapse

Answer

Chemical combustion

Answer

Nuclear fission of uranium

Question 2

Which property of a star determines its position on the main sequence?

Accepted Answer

Its mass

Answer

Its distance from Earth

Answer

Its apparent brightness

Answer

Its age only

Question 3

What color are the hottest stars?

Accepted Answer

Blue

Answer

Red

Answer

Yellow

Answer

Orange

Question 4

The Hertzsprung-Russell diagram plots luminosity against which stellar property?

Accepted Answer

Surface temperature

Answer

Distance

Answer

Rotation speed

Answer

Magnetic field strength

Question 5

What happens to a Sun-like star when it exhausts hydrogen in its core?

Accepted Answer

It expands into a red giant

Answer

It immediately becomes a black hole

Answer

It stays unchanged forever

Answer

It splits into two stars

Question 6

What is a protostar?

Accepted Answer

A forming star not yet fusing hydrogen steadily

Answer

A dead remnant of a supernova

Answer

A fully evolved white dwarf

Answer

A planet larger than Jupiter

Question 7

Which spectral class is used to describe the Sun?

Accepted Answer

G

Answer

O

Answer

M

Answer

B