Low- Mass Stars Both High-Mass Stars

Form inside a nebula

Produce energy by fusion

Go through Main Sequence stage

Less time in Main Sequence- use fuel quickly

Main sequence into Super Giant

No more fuel- super giant explode

Supernova

Become either:

Neutron Star

Black Hole

More time spent in Main Sequence- use fuel more slowly

Star expands into a giant star

Giant star sheds outer layers become a white dwarf

GALAXIES HAVE DIFFERENT

SIZES & SHAPES

Space ScienceChapter 4: Section 4.3

What is a Galaxy?huge grouping of stars, gas, and dust held together by gravity

How did the Milky Way get it’s name?because of its milky and hazy appearance

The Milky Way Galaxy is shaped like a disc with a huge bulge in the middle.

Why do we not see the center of the galaxy from Earth?

The center of the galaxy is hidden by all of the surrounding dust.

Review: What is a light-year?The distance it takes for light to travel in one year

Which is?6 trillion miles

The main bulge of

the galaxy is 26,000

light years from the

sun.

The Milky Way contains clouds of dust and gas called nebula.

Review: Why are nebula important?

Nebula are the birth place of stars

How we Classify Galaxies:

Spiral GalaxyHave arms of stars

and dust that curve away from the center

Has a central bulge which consists mostly of old stars

Spiral arms are new stars

Elliptical GalaxyShaped like spheres

or eggsNo dust or gas

between starsAll stars are old

Irregular GalaxyFaint galaxiesNo definite shapeSmaller than other

galaxiesHave fewer starsContains mostly

young stars

Types of Galaxies- KIM StrategyKey Concept Information

Spiral Galaxy *Have arms of stars and dust that curve away from the center *Has a central bulge which consists mostly of old stars*Spiral arms are new stars*Example: The Milky Way

Elliptical Galaxy *Shaped like spheres or eggs*No dust or gas between stars*All stars are old

Irregular Galaxy *Faint galaxies*No definite shape*Smaller than other galaxies*Have fewer stars

Memory Clue In the last column draw a picture of the

type of GalaxyRefer to page 132 if you need a reference point

When finished:Get a Picture Sort Sheet from Miss. HudakCut and sort the pictures according to their

shapeStaple them to the appropriate column

Review

http://www.brainpop.com/science/space/galaxies/