Download Star Life Guided Notes

The Death Of a Star
Ask not for whom the bell tolls,
it tolls for thee
How do we “know” stars die?
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____________ reveal different types of
stars.
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How did they get there?
Physics tells us how stars work.
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__________ depends on mass (L:M4) (Gas)
Fusion principles (4 H  1 He) tell us the rate
stars use energy. (kinda like MPG on a car.)
Stars will run out of ___. (the dial goes to “E”)
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Every star fights a “________”.
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_______ force pulling the star together.
Fusion “_____” pushing the star apart.
Most stars find a balance.
Some stars are never balanced:
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Gravity
Cephids pulse as they grow
larger and smaller.
Fusion
Cepheus
A star’s fate is chosen at birth
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The outcome of the battle is determined by
______ and _______ means
Three paths
Fate of Star
Depends on
MASS
Stars Like The Sun
Stars Slighly Larger
Than the Sun
Very Large Stars
Small Stars
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Small stars last longer
(don’t consume fuel as
quickly)
____________on HR
diagrams.
“Burn” ________ for
most of their lifetime.
Red Giants
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As star runs out of hydrogen, the core _____
Gravity starts to “win” --> _______ in core.
Increased “pressure” starts ________ fusion
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150 Million K
Carbon & Oxygen Products
________ temperature makes outer part of
star _________ yet….
Expanded surface is actually “_______” so
appears _____
Red Giants
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Stars less than 1.4 Solar Masses
Gravity is _______
Outer layers eventually “puff off” - not
enough gravity
Planetary ________ forms from gas
____________ remains
If it’s a cloud,
why does it look
like a ring?
Cat’s Eye: Another Planetary
Nebula
White Dwarfs
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Carbon/Oxygen
Matter is ___________
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One teaspoon = a pickup truck
Electron/quantum pressures balance gravity
Very Hot : 30,000K to 200,000 K
Slowly Cool to Black Dwarfs
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So slow, none exist yet.
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Except this guy 
White Dwarfs
Red Supergiants
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Stars more than 1.4 Solar Masses
Gravitational Core Energy Reaches ___ Million K
Carbon turns to _______________
With enough mass, even heavier elements fused
At each step, less and less energy yielded -->
shorter duration
Star keeps getting ________!
_______ is the end of the road….
The most famous S-G
Fusion Layers in a Supergiant
Why Stop at Iron??
Review
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Mass
______
determines the fate of a star.
gravityand _____
fusion
The two forces acting on a star are ____
When a star reaches the end of its life it begins to
helium and it ______.
fuse ______
swells
planetary
When fusion stops a typical star will producenebula
a __
white dwarf
and become a ______
_____.
Even the largest stars can’t fuse elements heavier
iron
than _____.
The party is over…
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Once _____ is in the core, outwards
pressure ceases
Core ________ at 1/4 the speed of light &
takes about 1/10 of a second
Collapse of the core to about 100 km across
Outer layers “bounce” of the solid core
Releases 100x the energy of our sun
produces in it’s lifetime -- in 1/10 of a
second!!!
A supernova
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Note the before / after differences
1987A
After the party…
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Lot’s of _________ hanging out during this
explosion
Neutrons “_________” with lighter elements
making heavy elements:
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Calcium, Gold, Zinc, Uranium, etc…
Forget Hollywood …..
We are all stars!!!
Aftermath:
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After a supernova explosion you can wind
up several possibilities
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Nebula & Neutron Star
Nebula & Pulsar
__________
Nebula
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________ of material left from the
explosion
The “Primordial Goo” for new stars,
planets, & people!
Supernova 1987
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Very complicated
structure
Nearby star
affecting the cloud
Our new neighbors?
Neutron star
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Forms if the remaining core is between 1.4
and 3 times the ____________
All this mass in the size of _________!
One teaspoon > The Sears Tower
All available space in the atom (which is
99.9999% space) is removed.
Neutron Star
Pulsar
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Neutron star that ______.
Spinning magnetic field channels radiating
energy into ______.
If this beam isn’t always pointing at us - it
_______ like a lighthouse.
First Pulsar was mistaken as ________
communication
A Pulsar
Black Holes
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Remaining Core is more than 3x the sun.
Gravity overcomes ___________, neutrons
vanish
Matter in the core overlaps : a singularity
Gravity prevents ______ from ________.-->
Black Hole
Closest light can get without being trapped:
“______________”
3 S.M star = 55km E.H. (Chicago?)
Earth as a black hole? Compress it into a marble!
Finding Black Holes
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May pull matter off a nearby
star - Accretion Disk XRays
Immense mass in the center
of galaxies
A trip to a black hole
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Pretty Short
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Difference in gravity between your head and
feet literally pull you apart.
Once you hit the E.H. you aren’t coming
back.
Everything you are is crushed into a single
point - you no ____________
No one would see you enter the Black Hole
because time stands still at the edge.
Black Holes - Expert Testimony
Black Holes –More Expert
Testimony