How a Star is Born, Lives, and Dies
Matt Frisco
Pre-Stellar Gas CloudsHydrogen and Helium are the most abundant gasses in the Universe.
They form a cloud due to gravity. Example of a gas cloud.
Functions of a Gas Cloud
It gets bigger and starts to spin.Gravity draws more gas to it.The gasses are hydrogen, helium, and lithium.
Spinning causes the cloud to condense.
It spins faster and gets denser until it reaches critical mass.
A Star is BornThe cloud gets smaller, denser, and hotter.
Eventually hydrogen begins to fuse.2 hydrogen atoms become 1 helium atom.
This process releases light and heat energy.
Then the star lights up.
Early Days of a Star
Fusion continues in the core where its hottest.
The size depends on how much gas was in the cloud.
Temperature depends on how much gas is fusing.
Bigger hotter stars fuse more.Smaller cooler stars fuse less.
Classifying Stars
Stars are many colors, sizes, and temperatures.
Characteristics of stars are dependant of each other.
For example: Big stars are hotter and bluer.
Examples of Star ColorStars can have many colors
The most common are yellow and white
Blue are biggest and hottest
Red and Orange are average
The Hertzsprung–Russell Diagram
The HR Diagram groups stars.The diagram was created in 1910.The diagram tells us everything about stars.
All the information helps us understand a stars lifespan.
H-R Diagram Example
What the Diagram Measures
The sides measure the brightness, spectral class, temperature, and magnitude (size relative to our sun).
The dots represent the stars.The colors of the dots are the colors of the stars.
All of this information helps us understand a stars lifespan.
Types of Stars
The curve shape through the middle are the main sequence stars.
The bottom left are white dwarfs.The top right are red giants.The top left are blue super-giants.
Main Sequence Stars
Most stars are currently main sequence.
Main sequence stars are many colors and temperatures.
Main sequence stars fuse hydrogen and helium and other light gasses.
Stars jump in and out of the main sequence.
Other Stars
Some stars live their whole lives off the main sequence.
Some jump on and off.
Some special stars are blue giants and white dwarfs.
Blue giants are big, bright, and hot.
White dwarfs are small, dim. and cool.
Blue giants don’t live long and white dwarfs live long.
Lives of Stars
Stars live for 5 million-10 billion years.Stars turn mass into energy.Stars fuse all elements up to Iron; but not heavier.
Stars and nebula make up 98 percent of all matter.
Life wouldn’t be possible without stars.Stars are usually at least 3 light years from each other.
Our StarThe name of the Sun
is SolSol is 4.6 billion
years old It will live another 5
billion years It takes 8 minutes for
light to reach Earth Sol can fit 1million
Earths inside of it
Death of Stars
When the star cannot fuse anymore it dies
Small stars dim down and offSuper-giants explode in a supernovaAfter the supernova it collapses into a black hole
Black holes are small and dense
References GLCE E5.2F
-http://www.michigan.gov/documents/EARTHMMC_168211_7.pdf
Web Resources Oracle ThinkQuest http://
library.thinkquest.org/J002231F/Sun/factsaboutthesun.htm National Geographic http://
science.nationalgeographic.com/science/space/universe/stars-article.html Universe Today
http://www.universetoday.com/25145/interesting-facts-about-stars/
Picture references Published by Tonynetone, Star Colors (Self-given description), Taken Date August 21, 2010
(no upload date) via flickr, creative commons attribution license. Published by NASA Goddard Photo and Video, Hubble Reveals Heart of Lagoon Nebula,
Taken Date July 15, 2010 (no upload date) via flickr, creative commons attribution license. Published by NASA Goddard Photo and Video, Sun’s Surface May 18, 2010, Uploaded
June 21, 2010 via flickr, creative commons attribution license. Published by Wikimedia Commons, H-R Diagram afr.GIF uploaded May 16 2007, via
Wikimedia Commons, Creative Commons Attribution Share-Alike License