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

2. Magnitude/luminosity = how bright
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.
Magnitude
Click for Life Cycle of Stars BrainPOP:
Click for Life Cycle of Stars Animation:
2 of 11

3. 2. Gravity pulls material into a sphere that becomes dense, hot
Black Dwarf
Iike our Sun!
Nebula
1. Large cloud of gas & dust where stars form.
2. Gravity pulls material into a sphere that becomes dense, hot
& ignites.
4. Outer layers come off
5. Collapses to just its core
3. Expands or
Explodes!
3 of 11

4. What is Nebula?
A nebula is an interstellar cloud of dust, hydrogen gas, helium gas and other ionized gases. Stars form here.

5. Stars The Sun 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

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

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

8. Electromagnetic Spectrum
10 of 11
Electromagnetic Spectrum
The range of all the waves that can travel through matter as well as empty space. R O Y G B I V
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, age of space objects or phenomena, temperature and mass