Image From: Astronomy Notes Part 1 Notes Created by Harris Middle School with graphics cited.

Universe Outer space and everything in it. Image from: Definition Adapted From: Access Science Glossary, page 324.

H-R Diagram: Shows the relationship between color, temperature, magnitude & size of stars. Color = temperature Magnitude/luminosity = how bright Our Sun is a main sequence star. Click for Life Cycle of Stars BrainPOP: 2 of 11 Magnitude Click for Life Cycle of Stars Animation:

Our Sun is a main sequence star. Click for Life Cycle of Stars BrainPOP: 2 of 11 Magnitude Click for Life Cycle of Stars Animation:

Magnitude A measure of how bright a star is. Images From: & content/uploads/2008/12/549px-sirius_a_and_b_hubble_photo.jpg; Definition: content/uploads/2008/12/549px-sirius_a_and_b_hubble_photo.jpgwww.thefreedictionary.com

Nebula Black Dwarf 1. Large cloud of gas & dust where stars form. 3. Expands Explodes! 5. Collapses to just its core 4. Outer layers come off or Iike our Sun! 3 of Gravity pulls material into a sphere that becomes dense, hot & ignites.

Stars An object made of gas that gives off energy –mainly hydrogen –helium The Sun medium in size & life span compared to other stars primary energy source for all processes on Earth much closer to Earth than any other star! about 4 ½ billion years old 1 of 11

Galaxy A large grouping of stars, gas and dust in space. 3 types 1.Spiral or Disc – bulge in center & distinctive spiral arms Example: Our galaxy, The Milky Way Our solar system is located within an arm 2.Elliptical – spherical or elongated 3.Irregular- no definite shape of 11

Light Year A measure of how long it takes light to travel through space in one year. Image From: Definition: 9 of 11

Galaxy A large grouping of stars in space. Image From: Definition:

Spiral Galaxy Image From: Definition: Galaxy M81 is a spiral galaxy A galaxy with a bulge in the center and distinctive spiral arms.

Irregular Galaxy A galaxy with an irregular shape. Barnard’s Galaxy is an irregular shaped galaxy. Image From: Definition:

Elliptical Galaxy A spherical or elongated- shaped galaxy. Image From: Definition: M87 is an elliptical galaxy.

Milky Way Galaxy Image From: Definition Adapted From: The name of the galaxy where we live.

Electromagnetic Spectrum The range of all the waves that can travel through matter as well as empty space. Image From : Definition: ROYGBI V 10 of 11 Scientists use different portions of the spectrum to learn about the universe. Ex: light waves can tell us what elements stars are made & if they are moving away or towards other objects.

Theories on the Origin of the Universe 1.Steady State – has always been the same 2.Oscillating Model - began by expanding, has slowed down & is now contracting 3.Big Bang - *the dominant theory 12 to 15 billion years ago Universe began as a dense point that exploded It rapidly expanded & began to cool down, forming stars, etc. Evidence  discovery of cosmic background radiation  red shift in EM spectrum suggest it is still expanding 11 of 11 Click for Big Bang BrainPOP: