A group of stars close enough to be held together by gravity and have the same proper motion
star cluster
This diagram shows the relationship between temperature and absolute magnitude of a star
Hertzsprung - Russel Diagrqm
As our sun ages the amount of this element will increase
helium
Galaxies that are not spiral or elliptical in shape are called this
Irregular galaxies
Stars are classified this way
color, size and absolute brightness (luminosity)
This is a massive cloud of gas and dust from which a star may form via gravity
nebula
This does not affect the apparent brightness of a star
How old the star is
This varies with the position from which a star is observed
apparent brightness
A collapsed star that is so dense that its gravity prevents even light from escaping
Black hole
The portion of a star between the core and the outer layer and corona is
radiation zone
When massive stars run out of fuel and succumb to their own gravity, they become on of these
supernovas
An immense star with significantly more mass than our sun.
Supergiant
What is the orbital shape of the planets in our solar system around the sun?
Elliptical
Name the three types of large galaxies.
spiral, elliptical, and irregular
Stars spend 90% of their lives in this stage
Main sequence
Nova
A stream of electrically charged particles sent into space by the sun
Solar wind
The ____________________________ states that the universe probably began about 13.7 billion years ago with an enormous explosion.
Big Bang Theory