Objectives:
1. What stage marks the birth of a star?
When the protostar reaches 10 million degrees K and nuclear fusion occurs. The star is “self-sufficient” and producing its own energy.
2. Why do all stars eventually die?
All stars eventually die because they run out of fuel
3. What stages make up the life cycle of a low, medium, and high mass star?
This chart lists the stages but does not include details you will be expected to know.
Interesting videos
What will happen to the Earth when the sun dies?
Life of a Star: 12 billion years in 6 minutes
NASA | Fermi Proves Supernova Remnants Produce Cosmic Rays
Full version Death Stars
http://www.youtube.com/watch?v=hr7gYxghZrg
Life and Death of Stars
http://www.youtube.com/watch?v=mzE7VZMT1z8
Life cycle of a Medium mass star
Nebula
Cloud of dust and gas
Protostar
A developing star, not yet hot enough for nuclear fusion to occur
Main sequence star
Core temp is at least 10 million K and nuclear fusion occurs
Star is a stable size as gravity pushing in is offset by gas pressure pushing out
Red Giant
All hydrogen in core gets consumed so star collapses causing the temp. to increase
Forms b/c zone of nuclear fusion moves outward
Planetary Neblua
During the collapse from a red giant to a white dwarf, a glowing cloud of gases is emitted
White dwarf
Remains of low and medium mass stars
Extremely small star w/ density greater than any substance on Earth
Black dwarf
A white dwarf that has cooled such that it is no longer emitting light