Chapter 3 Stars & Galaxies

What is a huge collection of stars called? galaxy

What is the sum of absolutely everything that exists? The universe

How is the universe changing all the time? It is constantly expanding & things are moving away from one another.

What is the name of a cool, dark, dead star? Black dwarf

What is the measure of how bright a star appears to be called? Apparent magnitude

The explosion of a star is called a __________. supernova

What kind of gas gives stars their energy? hydrogen

Name the three kinds of galaxies. Elliptical, spiral, irregular

What is the name of our galaxy? The Milky Way

What kind of galaxy is the Milky Way? spiral

What is the most common type of galaxy? elliptical

Which color stars are the hottest? Which are the coolest? Blue stars are hottest Red stars are coolest

When a massive stars dies, which two things can it become? Black hole OR neutron star

What is the first stage in the life cycle of alll stars? nebula

The distance that light travels in a year is called a _____________. Light year

What is the amount of light a star truly gives off called? Absolute magnitude

Who discovered that galaxies could be classified into three basic groups? Edwin Hubble

How does a star get its energy? Nuclear reactions in the center of the star

What determines a star’s color? The temperature

What is a region in space where the gravitational pull is so strong that not even light can escape it called? Black hole

How does our star (the Sun) compare to other stars in size? It is quite small when compared to other stars such as Betelguese

What is a collapsed red giant that shines dimly called? White dwarf

What is the dense remains of a star’s core after a supernova explosion called? Neutron star

The light that we see from our Sun left there how long ago? About 8 minutes

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