5.1 Stars
How bright a star looks is its ________.
apparent magnitude
Distances to stars are measured in units called _____.
light-years
The cloud of gas and dust in which a star is born is a _____.
nebula
galaxy
Stars shine because of a process called ______.
fusion
A light year measures _______
distance
supernova
Our solar system belongs to the
Milky Way galaxy
The actual brightness of a star is called its
absolute magnitude
Earth and the moon, Earth and the sun, Earth and the Sirius, Earth and Mars
Earth and Sirius
A small, hot, dense star
Everything that exists
universe
A star's brightness depends on which two things
distance and energy given off
What is the distance of one light-year?
9.5 trillion kilometers
One of the largest stars that forms after using up its hydrogen is a _______.
supergiant
Patterns of stars seen from Earth
constellations
During fusion in stars, hydrogen particles combine to form helium and ___
energy
Why do scientists use light-years instead of kilometers to describe some distances?
The numbers would be too large or difficult to read
Light cannot escape from _____.
black holes
Galaxies are divided into groups by their _____.
shape