STELLAR EVOLUTION

Star Formation

1) Nebula

Cloud of interstellar gas and dust Collapses due to its own gravity Begins Star Formation

2) Protostar

Rotating disk shape Hot condensed object at the center Fusion begins

3) Main Sequence Star

Fusing Hydrogen into Helium Longest phase of Sun’s Lifecycle

4) Red Giant

Sun expands beyond Venus’ orbit

5) Planetary Nebula

Outer layer of Star is driven off

6) White Dwarf

No longer Nuclear Supported by resistance of electrons

being squeezed together

7) Black Dwarf

Sun runs out of energy

Massive Stars

1) Nebula

2) Protostar

3) Main Sequence Star

4) Several Red Giant PhasesUntil iron has formed

Neutron Star

Extremely dense – 100 trillion times more dense than water

Very Small – a radius of approx. 10 km

Supernova

Massive explosion that blows off outer portion of neutron star

http://www.youtube.com/watch?v=0J8srN24pSQ

Black Hole

Only the most massive stars (20 times the size of the Sun)

Collapse of star continues forever Gravity so strong that light cannot

escape

http://www.youtube.com/watch?v=f_KLOFe2rDY