Download - 4.3 Galaxies are Different Shapes and Sizes
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/