Unit 3 Review - Stellar Evolution and Anatomy

Supernovas are one of the largest _______ in the Universe.

• events

• stars

• explosions

• objects

_____ stars evolve and move off the main-sequence first; then intermediate stars & so on.

• Low-mass

• Red giant

• High-mass

• White dwarf

For a sun-like star on the main sequence, change will gradually occur as it evolves.

• True

• False

Low-mass stars like our Sun will never explode.

• True

• False

Our Sun, along with most of the stars in our neighborhood, probably formed …

• … about 10 million years ago.

• … a few million years ago.

• … hundreds of millions of years ago.

• … billions of years ago.

• … at the beginning of the universe.

What is the force that keeps a main sequence star

from blowing apart?

• radiation pressure

• electron degeneration pressure

• the strong force

• magnetism

• gravitation

Which event marks the birth of a star?

• collapse of an interstellar cloud

• formation of the planetary nebula

• fusion of hydrogen atoms into helium atoms

• formation of a photosphere

• instability in an interstellar cloud

On an H-R diagram, a protostar would be…

• …above and to the right of the main sequence.

• …below and to the left of the main sequence.

• …below and near the right side of the main sequence.

• …above and near the upper left of the main sequence.

• …on the main sequence at the extreme lower right.

The single most important determinant of the temperature, density, radius, luminosity, and pace of evolution of a protostar is its

• chemical composition.

• mass.

• magnetic field.

• molecular composition.

• spin.

What is A?

Red giant

Nebula

Where fusion begins

Black dwarf

Main sequence star

White dwarf

Planetary nebula