Presentation on theme: "1. How do scientists measure our distance from stars that are too far to use the parallax effect? 2. How is this this related to absolute magnitude? Times."— Presentation transcript:
1. How do scientists measure our distance from stars that are too far to use the parallax effect? 2. How is this this related to absolute magnitude? Times Up!
Make a T-chart ◦ On one side list 3 things you think you know about stars. ◦ On the other side 3 list things you want to know about stars.
Not really empty Stars, planets, etc. Interstellar medium ◦ Dust and Gas ◦ Nebulas Orion Nebula a/ Large Magellanic Cloud 5a/
Nebulae are usually composed of 70% Hydrogen, 28% Helium, 2% heavier elements A force compresses the particles, they begin to contract together
Gravity at work ◦ More mass means more gravity; more gravity results in more mass, etc.
As the Gravitational forces between the particles increase, they begin to spin more rapidly Here is a demodemo The shrinking, spinning region begins to flatten onto a disk called a PROTOSTAR
Increased pressure and temperature Temperature continues to increase until it reaches about 10,000,000 O C when NUCLEAR FUSION begins and a star is born!
Little mass lots of energy E = mc 2
Fermi National Lab High temperatures 2 particles become 1 Releases a lot of energy
Energy heats up gas and causes outward expansion. Gravity pushes in. Forces balance out = Hydrostatic Equilibrium ◦ Stable adult stage star