sun, moon, earth, what kind of life cycle does a star have?
TRANSCRIPT
Sun, Moon, Earth,
What kind of life cycle does a star have?
Star “Birth”:
Star “Birth”:• All stars start out as part of a
Nebula.
Star “Birth”:• All stars start out as part of a
Nebula.– Nebula: A large cloud of gas and
dust spread out over an immense volume.
Star “Birth”:• In the densest part of a Nebula
gravity begins pulling the gas and dust together.
Star “Birth”:• In the densest part of a Nebula
gravity begins pulling the gas and dust together.
– A Protostar is formed when there is enough mass (gas and dust) concentrated to form a star.
Star “Birth”:• As gravity continues to shrink the
protostar it reaches a point where it is close to the size it will be. At this point it is called a T Tauri star.
Star “Birth”:• Once the gas and dust become so
dense and hot (about 15 million °K) that nuclear fusion starts the star is “born”.
Star “Birth”:• Once the gas and dust become so
dense and hot (about 15 million °K) that nuclear fusion starts the star is “born”.
– This process can take from 60,000 to 150 million years.
Star Fact:• With all of the nuclear fusion
happening why doesn’t the star “blow up”?
Star Fact:• With all of the nuclear fusion
happening why doesn’t the star “blow up”?
– Stars have a gravitational equilibrium which means gravity pulling in and nuclear fusion pushing out are exactly balanced.
Star “Life”:• How long a star lives depends on
its mass (how much fuel it has to burn up).
Star “Life”:• How long a star lives depends on
its mass (how much fuel it has to burn up).
– Large mass stars live the shortest.
Star “Life”:• How long a star lives depends on
its mass (how much fuel it has to burn up).
– Large mass stars live the shortest.
– Low mass stars live the longest.
Star “Life”:Types of Stars
"O"
"B"
"A"
Blue
Orange
Red
"F"
"G" (our sun)
"K"
"M"
Largest
Smallest
Size
up to 200 billion years
up to 10 billion years
up to 5 million years
Life time
Star “Death”:• When a star runs out of “fuel” it
begins to die.
Star “Death”:• When a star runs out of “fuel” it
begins to die.– Once this happens the star will
become one of three things.
Star “Death”:• When a star runs out of “fuel” it
begins to die.– Once this happens the star will
become one of three things.• White dwarf
Star “Death”:• When a star runs out of “fuel” it
begins to die.– Once this happens the star will
become one of three things.• White dwarf• Neutron star
Star “Death”:• When a star runs out of “fuel” it
begins to die.– Once this happens the star will
become one of three things.• White dwarf• Neutron star• Black hole
Star “Death”:• Low to medium mass stars (A-M)
Star “Death”:• Low to medium mass stars (A-M)
– As a star runs out of fuel its outer layers expand.
Star “Death”:• Low to medium mass stars (A-M)
– As a star runs out of fuel its outer layers expand.• Becomes a Red Giant.
Star “Death”:• Low to medium mass stars (A-M)
– As a star runs out of fuel its outer layers expand.• Becomes a Red Giant.
– Outer layers are “ejected” from the star’s core as a Planetary Nebula.
Star “Death”:• Low to medium mass stars (A-M)
– As a star runs out of fuel its outer layers expand.• Becomes a Red Giant.
– Outer layers are “ejected” from the star’s core as a Planetary Nebula.
– The core that is left behind cools and becomes a White Dwarf.
Star “Death”:• Low to medium mass stars (A-M)
– As a star runs out of fuel its outer layers expand.• Becomes a Red Giant.
– Outer layers are “ejected” from the star’s core as a Planetary Nebula.
– The core that is left behind cools and becomes a White Dwarf.• Glows because it is still really hot.
Star “Death”:• Low to medium mass stars (A-M)
– As a star runs out of fuel its outer layers expand.• Becomes a Red Giant.
– Outer layers are “ejected” from the star’s core as a Planetary Nebula.
– The core that is left behind cools and becomes a White Dwarf.• Glows because it is still really hot.
– After it finishes cooling it becomes a Black Dwarf.
Star “Death”:• High mass stars (O and B)
Star “Death”:• High mass stars (O and B)
– Same as small mass up to Red Giant phase.
Star “Death”:• High mass stars (O and B)
– Same as small mass up to Red Giant phase.
– Fusion continues up to Iron (Fe).
Star “Death”:• High mass stars (O and B)
– Same as small mass up to Red Giant phase.
– Fusion continues up to Iron (Fe).
– Iron absorbs energy but doesn’t go through fusion.
Star “Death”:• High mass stars (O and B)
– Same as small mass up to Red Giant phase.
– Fusion continues up to Iron (Fe).
– Iron absorbs energy but doesn’t go through fusion.• Releases the energy in a massive
explosion as a Supernova.
Star “Death”:• High mass stars (O and B)
– Same as small mass up to Red Giant phase.
– Fusion continues up to Iron (Fe).
– Iron absorbs energy but doesn’t go through fusion.• Releases the energy in a massive
explosion as a Supernova.
– Form one of two things.
Star “Death”:• High mass stars (O and B)
Star “Death”:• High mass stars (O and B)
– Neutron Stars: Forms from the remains of the old star.
Star “Death”:• High mass stars (O and B)
– Neutron Stars: Forms from the remains of the old star.• Very very high density and very very
small.
Star “Death”:• High mass stars (O and B)
– Neutron Stars: Forms from the remains of the old star.• Very very high density and very very
small.– As much as three times the mass of our
star in an area the size of a city.
Star “Death”:• High mass stars (O and B)
– Neutron Stars: Forms from the remains of the old star.• Very very high density and very very
small.– As much as three times the mass of our
star in an area the size of a city.– Some give off regular pulses of radio
waves and are called pulsars. (these were originally called LGMs).
Star “Death”:• High mass stars (O and B)
Star “Death”:• High mass stars (O and B)
– Black Holes: “Objects” in space that have such high gravity that nothing (not even light) can escape them.
Star “Death”:• High mass stars (O and B)
– Black Holes: “Objects” in space that have such high gravity that nothing (not even light) can escape them.• We can find them because….
Star “Death”:• High mass stars (O and B)
– Black Holes: “Objects” in space that have such high gravity that nothing (not even light) can escape them.• We can find them because….
– Stars that are close to them are “pulled” by the gravity of the black hole.
Star “Death”:• High mass stars (O and B)
– Black Holes: “Objects” in space that have such high gravity that nothing (not even light) can escape them.• We can find them because….
– Stars that are close to them are “pulled” by the gravity of the black hole.
– Gases in the area are pulled in so fast (like a drain in a sink) that they spin around the black hole and we see the heat given off.
Sun, Moon, Earth,
Where are we in the big picture?
Our cosmic address:• Some numbers you need to know:
Our cosmic address:• Some numbers you need to know:
– Light year =
Our cosmic address:• Some numbers you need to know:
– Light year = 9,439,922,663,400 km
Our cosmic address:• Some numbers you need to know:
– Light year = 9,439,922,663,400 km
– AU = Astronomical Unit
Our cosmic address:• Some numbers you need to know:
– Light year = 9,460,730,472,581 km
– AU = Astronomical Unit• Average distance from the Earth to the
sun
Our cosmic address:• Some numbers you need to know:
– Light year = 9,460,730,472,581 km
– AU = Astronomical Unit• Average distance from the Earth to the
sun
– 1 AU =
Our cosmic address:• Some numbers you need to know:
– Light year = 9,460,730,472,581 km
– AU = Astronomical Unit• Average distance from the Earth to the
sun
– 1 AU = 149,597,871 km
Our cosmic address:• Some numbers you need to know:
– Light year = 9,460,730,472,581 km
– AU = Astronomical Unit• Average distance from the Earth to the
sun
– 1 AU = 149,597,871 km
– 1 light year =
Our cosmic address:• Some numbers you need to know:
– Light year = 9,460,730,472,581 km
– AU = Astronomical Unit• Average distance from the Earth to the
sun
– 1 AU = 149,597,871 km
– 1 light year = 63,239 AU
Our cosmic address:• Some numbers you need to know:
– Light year = 9,460,730,472,581 km
– AU = Astronomical Unit• Average distance from the Earth to the
sun
– 1 AU = 149,597,871 km
– 1 light year = 63,239 AU
– Pluto’s orbit around the sun =
Our cosmic address:• Some numbers you need to know:
– Light year = 9,460,730,472,581 km
– AU = Astronomical Unit• Average distance from the Earth to the
sun
– 1 AU = 149,597,871 km
– 1 light year = 63,239 AU
– Pluto’s orbit around the sun = 39.5 AU
Our cosmic address:• Name:
Our cosmic address:• Name:
• Street:
Our cosmic address:• Name:
• Street:
• City, State:
Our cosmic address:• Name:
• Street:
• City, State:
• Country:
Our cosmic address:• Name:
• Street:
• City, State:
• Country:
• Planet:
Our cosmic address:
Our cosmic address:• Name:
• Street:
• City, State:
• Country:
• Planet:
• Solar System: (about 79 AU)
Our cosmic address:
Our cosmic address:• Name:
• Street:
• City, State:
• Country:
• Planet:
• Solar System:
• Galaxy: (6,327,000,000 AU)
Our cosmic address:
Our cosmic address:• Name:
• Street:
• City, State:
• Country:
• Planet:
• Solar System:
• Galaxy:
• Local Group:
Our cosmic address:
Our cosmic address:• Name:• Street:• City, State:• Country:• Planet:• Solar System:• Galaxy:• Local Group:• Local Super Cluster:
Our cosmic address:
Our cosmic address:• Name:• Street:• City, State:• Country:• Planet:• Solar System:• Galaxy:• Local Group:• Local Super Cluster:• Universe: