1. Intrinsic in⋅trin⋅sic
   /ɪnˈtrɪnsɪk, -zɪk/ Show Spelled Pronunciation [in-trin-sik, -zik] Show IPA
–adjective 1. belonging to a thing by its very nature: the intrinsic value of a gold ring. 2. Anatomy. (of certain muscles, nerves, etc.) belonging to or lying within a given part.

2. THE LIFE OF A STAR

3. NEBULA

5. Nebula cloud of gas and dust
Birthplace for new stars and solar systems
Gravity contracts to become……

8. EAGLE NEBULA

9. PROTOSTAR
Nebula core collapses and heats up, nuclear fusion is about to begin

10. Main Sequence Star Nuclear fusion has begun!
H+ H  He + energy
Fusion creates HEAT, LIGHT, RADIATION
Life in Main Sequence depends on MASS OF STAR
Massive = short life in MS
Less massive = long life in MS
90% of star’s life is in Main Sequence

11. MAIN SEQUENCE

12. Red Giant All Hydrogen in core has fused Helium + helium carbon
Star “puffs out” and cools off (produces RED COLOR)
Very Bright
Cool Temperature

14. RED GIANT

16. Planetary Nebula/White Dwarf
Core shrinks to its most compact state (white dwarf)
HOT!
dim
Outer layers ejected and form a cool gas/dust shell
Planetary nebula

17. PLANETARY NEBULA
WHITE DWARF

20. WHITE DWARF

22. Black dwarf No more fusion Hard to detect
May take a trillion years- do they exist?

23. Normal life cycle Birth (nebula) Main sequence (last 10 billion years)
H running out
Red Giant
He running out
White dwarf
Dies
Black dwarf (cold dark mass)
fusion

24. 3X MORE MASSIVE THAN THE SUN
SUPERSTARS!
3X MORE MASSIVE THAN THE SUN

25. Start the same way BUT SHORTER LIFE-SPAN
Nebula
Protostar
Main sequence
RED SUPERGIANT (larger than red giant)

26. RED SUPERGIANT

27. Supernova
Outer layers first contract, then explode outward.

28. SUPERNOVA before/after 1987

30. SUPER NOVA

31. Supernova Remnants: Cas A
Optical
X-ray
Cas A is 300 years old. The remnant is about 10 light-years in diameter, and 10,000 light-years away.
X-ray: outer shock wave is from the initial supernova explosion ripping through the interstellar medium at 10 million miles per hour. Temperatures may reach 50 million degrees. The inner shock is the ejecta from the SN heating up the circumstellar shell, heating it to 10 million degrees
The optical image of Cas A shows matter with a temperature of about ten thousand degrees. Some of these wisps contain high concentrations of heavy elements and are thought to be dense clumps of ejected stellar material.
Cas A x-ray and optical images from

32. Neutron Star Supernova core contracts to ~ 10-30 km
Densest object known!
Rapid rotation of star releases repeating bursts of radio signals (PULSARS)

33. OR….. Black Hole MOST MASSIVE OF ALL STARS become this
Gravity causes severe core contraction
NOTHING can escape a black hole!

34. ACCRETION DISK
BLACK HOLE

35. Material pulled from another companion star

36. MASSIVE STARS (3X SUN) SUPERSTARS!!
Nebula
Main sequence (last millions of years)
Red supergiant
Super Nova (1 billion degrees)
Neutron star (core, pulsars)
Black hole

37. Size comparison

38. The End of the Line for Massive Stars
Massive stars burn a succession of elements.
Iron cannot be fused further.
Instead of releasing energy, it uses energy.
Fusion stops at Iron, and star collapses under its own weight.
The star contains products of the fusion processes.