Download Life Cycle of a Star Vocabulary

Life Cycle of a
Star
Presented by Kesler Science
Essential Questions:
1. What is the life cycle of a star?
2. How does the mass of a star
predict the sequence of events
in the life cycle of a star?
Life Cycle of a Star Vocabulary
Life cycle of a star
The sequence of
changes that occur
in a star as it ages.
Infant
Death
Old Age
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Youth
Middle
Age
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Quick Action – INB Templates
Life Cycle of a Star
1. Cut out the Life Cycle of
a Star template.
2. Glue it into your journal.
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Life Cycle of a Star Vocabulary
Where do stars come from?
Interstellar medium
• A thinly spread area
of gas and dust
• The gas is mostly
hydrogen (H2)
• The dust is mostly
carbon (C) and
silicon (Si)
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Life Cycle of a Star Vocabulary
Nebula
• Interstellar medium
begins to collect into
big clouds.
• The birthplace of stars,
as stars are made up
of gas and dust.
• “Star Nursery”
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Life Cycle of a Star Vocabulary
Protostar
• Inside the nebula are regions
of greater and less gravity
causing the gas and dust to
pull together.
• As more atoms gather, their
gravitational attraction
increases.
• Not a very stable phase
because many reactions are
occurring within the
protostar.
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Life Cycle of a Star Vocabulary
A Star is Born –
• when a critical
temperature in the core of
the protostar is reached
and nuclear fusion
begins.
• Hydrogen (H2) begins
fusing into helium (He).
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Life Cycle of a Star Vocabulary
Star
• An extremely hot ball of gas,
with hydrogen (H2) fusing into
helium(He)at its core.
• Spend most of their lives fusing
hydrogen
• When the hydrogen is used
up, stars fuse helium to
carbon
• They are always trying to
achieve equilibrium
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Life Cycle of a Star Vocabulary
Main Sequence
• Stars live out most of their
lives in this phase.
• Stars have achieved
nuclear fusion.
• Stars stays at equilibrium.
• Stars radiate (shine) energy
into space.
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Life Cycle of a Star Vocabulary
Low Mass Stars in Main Sequence
The mass of a star determines
what happens to it after living
most of its life in Main Sequence.
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Life Cycle of a Star Vocabulary
Low mass stars –
• Half as massive as
the Sun
• Can live 80 to 100
billion years in Main
Sequence.
• Example - Red Dwarf
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Our Sun –
• A medium sized, low
mass star
• Spends about 10
billion years in Main
Sequence.
• A Main Sequence
star for about 4.57
billion years.
Life Cycle of a Star Vocabulary
Red Giant
• Phase after Main Sequence
• Low and high mass Main
Sequence stars progress to Red
Giants.
• Outer gas layers of the star
expand
• As the star uses all its fuel its core
shrinks.
• Red in color
• High luminosity
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Life Cycle of a Star Vocabulary
Planetary nebula
• Occurs at the end of a low
mass Red Giant’s life.
• The outer layers of the star
are expelled.
• The core is very hot and
luminous.
• The outer shell appears as
bright colored gas clouds.
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Life Cycle of a Star Vocabulary
White Dwarf
• Forms when a low mass star runs
out of fuel.
• The core of a planetary nebula
• Final stage in the cycle for low
mass stars
• Incredibly dense
• Gravity is 350,000 times that of
gravity on Earth.
• Will change colors as it cools
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Life Cycle of a Star Vocabulary
Black Dwarf
• End product of a White
Dwarf
• The last stage of stellar
evolution for low mass
stars
• No longer emits heat or
light
• No longer a star
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Life Cycle of a Star Vocabulary
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Quick Action – Life Cycle of a Star
______mass
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_____ mass
Quick Action – Life Cycle of a Star
Low Mass
High Mass
Main Sequence
SUN
Red Giant
Planetary Nebula
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Star-Forming Nebula
White Dwarf
Life Cycle of a Star Vocabulary
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Life Cycle of a Star Vocabulary
High Mass Main Sequence
The mass of a star determines what
happens to it after living most of its life
in Main Sequence.
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Life Cycle of a Star Vocabulary
High Mass stars •10 times as massive as our
Sun
•Remains in Main Sequence
for about 20 million years.
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Life Cycle of a Star Vocabulary
Red Super Giants
• The same thing as a
giant star only much
bigger.
• As a star gets older it
begins to run out of
fuel and expand.
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Life Cycle of a Star Vocabulary
Supernova
• Last stage of a massive star’s
life
• Occurs as the star runs out of
nuclear fuel, some of its mass
flows into its core.
• Core becomes so heavy that
it cannot withstand its own
gravitational force.
• The core collapses and results
in a giant explosion.
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Life Cycle of a Star Vocabulary
Neutron Star
• The core left behind in a
supernova
• Very dense - 1Tsp. = 1billion tons
• Gravity is 2 billion times that of
the gravity on Earth.
• Gravity presses the material in
on itself so tightly that protons
and electrons combine to make
neutrons, yielding the name
"neutron star”.
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Life Cycle of a Star Vocabulary
Black Hole
• Forms when very
massive stars collapse
at the end of their life
cycle
• A large area in space
with a very strong
gravitational pull
• Nothing can escape,
even light.
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Quick Action – Life Cycle of a Star
Low Mass
High Mass
Main Sequence
Massive Star
SUN
Red Super Giant
Red Giant
Star-Forming Nebula
Supernova
Neutron Star
Planetary Nebula
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White Dwarf
Black Hole
Quick Action – Life Cycle of a Star
Journal Activity
• In your INB write a
passage that
compares the human
life cycle to the life
cycle of a star.
• Provide as much
detail as possible.
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Check for Understanding
Can you…
1. Describe why a star
goes through a cycle?
2. Predict what stages a
low mass star will pass
through in its lifetime?
3. Label a blank Life
Cycle of a Star
diagram?
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__________
___________