Presentation Transcript
Life Cycles of Stars: Life Cycles of Stars
The Hertzsprung-Russell Diagram: The Hertzsprung-Russell Diagram
How Stars Form: How Stars Form Collapsing gas and dust cloud
Protostar - mostly infrared
Main Sequence Stars: Main Sequence Stars Brown Dwarf
Red Dwarf
Normal Star
All Objects Exist Because of a Balance Between Gravity and Some Other Force: All Objects Exist Because of a Balance Between Gravity and Some Other Force People, Planets-Interatomic Forces
Normal Stars-Radiation
White Dwarfs-Electron Repulsion
Neutron Stars-Nuclear Forces
Black Holes-No Known Force
How Stars Die: How Stars Die Main Sequence Stars Brighten With Age
The More Massive a Star, the Faster it Uses Fuel
Giant Phase
White Dwarf
Supernova
Neutron Star - Pulsar
Black Hole
Historical Supernovae: Historical Supernovae 1006 - Chinese
1054 - Chinese, European, Anasazi?
1572 - Tycho’s Star
1604 - Kepler’s Star
1987 - Small Magellanic Cloud (170,000 l.y.)
Life (Briefly!) Near a Supernova: Life (Briefly!) Near a Supernova Sun’s Energy Output = 77 billion megatons/second
Let’s relate that to human scales. What would that be at one kilometer distance?
77 x 1015 tons/(150 x 106km)2 = 3 tons
Picture a truckload of explosives a km away giving off a one-second burst of heat and light to rival the Sun
Now Assume the Sun Goes Supernova: Now Assume the Sun Goes Supernova Brightens by 100 billion times
Our 3 tons of explosive becomes 300,000 megatons
Equivalent to entire Earth’s nuclear arsenal going off one km away - every second
This energy output would last for days
Planetary Systems: Planetary Systems Protoplanetary Disks
Accretion of Planets
Expulsion and Migration of Planets
About 30 extrasolar planets known
Our Solar System may be unusual?
Protoplanetary Disks in Orion: Protoplanetary Disks in Orion