Download Life Cycle of Stars

Life Cycle of
Stars
• Stars
form from
Stars
clouds of gas and
dust to create
Nebula
• Nebula – cold,
dense, dark
• Gravity pulls on the
nebula causing it to
collapse and form a
protostar
Protostar
• Continues to pull in surrounding gas
• When hot enough = nuclear fusion begins
• Once the gas and dust blow away, the star can be seen
• All stars (low and high mass) start out here
•When atomic nuclei form a nucleus
•Hydrogen fuses into helium
•All stars (low and high mass) go through this
•How long a star lives depends on its mass
•Small stars use their fuel slow = longer lives
Nuclear Fusion
Protostar → Main Sequence - Sun-like Star →
→ Giants
•Giants are larger because of the gasses have expanded.
•Runs out of hydrogen, so it expands as it uses helium for fuel.
•Giants are also red in color due to a lower surface temperature (cools as it expands).
Life
cycle
of
a
•Stops producing energy when helium is exhausted
•Gives off outer atmosphere as an expanding cloud low
of dust mass star
→ Planetary Nebula
→ White Dwarf
•Core of star becomes dense and hot, slowly giving off energy (runs out of fuel)
•Very small (about size of Earth)
•Shine for billions of years
•As it cools = it dims = it dies out = → Black Dwarf
•Completely cooled and dark (core made of carbon)
Protostar →Main Sequence-Massive Stars(1.5-3 times the size of our sun)→
→Red Supergiants
•
•
•
Fusion of heavier elements
Makes the star expand more
Can be the size of our solar system (WOW!)
→Supernova
•
•
Star continues to expand, then it uses up all the nuclear fusion fuel = no energy remains
Star begins to collapse because the core is too massive to be supported by pressure
causing it to explode sending outer layers into space (the newly created elements are
spread far & wide)
→Black Hole
• Core remains
● Supernova is so massive that it continues to
→Neutron Star
collapse
• The collapsed core of a large star ● Most massive supergiants
● Invisible object that nothing can escape it, not
• Small dense ball of neutrons
even light
● Matter can be observed being pulled in by gravity
Black Hole Video
● Matter becomes hot and emits x-rays we can see