selection case
Welcome to SCIE 150:
The Science of Everything
Today: Astronomy
Today
• Stars: how are they born, how do they live, how do they die
▫ How do different stars vary in these paths
• Planets: how are they born
▫ What are the planets of our solar system like
• Constellations are
A. Stars that are nearby each other in space
B. Stars that appear to be near each other, but may be very far apart The Sun
• Our Sun is
A.
B.
C.
D.
An average star
A very small star
A very big star
Not a star, it’s the Sun
Stars have Lives
• < 2 Msun
• > 8 Msun
6
Orion Nebula
(sword of Orion) is a current site of lots of star formation 7
Nebula collapse spinning disk
• Gas cloud collapses, heats up, spins, flattens
• Go from a big nebula to a small spinning disk
The protostellar disk
Planets
• Planets are
A. Formed around a star as it is born
B. Caught by an adult star
C. Caught by a young star
10
Circumstellar Disks
11
Other places we see disks
The Living Star
Gravitational equilibrium
Hydrogen Fusion:
600 million tons of H into 596 million tons of He per second
Death of the Sun
Layers
15
Planetary Nebulae
• Expanding shell of gas, lit by intense UV radiation • Misnomer – they kinda look like planets
17
The Dead Heart: The White Dwarf
Planetary nebula dissipates...
1Msun = 333,000 MEarth
• Can’t be larger than 1.4 Msun
Star Lifetimes
Fates of Stars
• < 2 Msun
• > 8 Msun
Layers in the Death Throes of a High-Mass Star
• Iron is the most stable • Will not burn
• Core collapses
• Explodes
• Type II
Supernova
21
The Crab Nebula
22
One teaspoon of Neutron Star stuff weighs as much as a mountain
If more than 3Msun is left behind, gravity is too much to be held up...
23
The Sun may become a black hole
A. True
B. False
If it did
A. We would be sucked in
B. We would continue to
The Science of Everything
Today: Astronomy
Today
• Stars: how are they born, how do they live, how do they die
▫ How do different stars vary in these paths
• Planets: how are they born
▫ What are the planets of our solar system like
• Constellations are
A. Stars that are nearby each other in space
B. Stars that appear to be near each other, but may be very far apart The Sun
• Our Sun is
A.
B.
C.
D.
An average star
A very small star
A very big star
Not a star, it’s the Sun
Stars have Lives
• < 2 Msun
• > 8 Msun
6
Orion Nebula
(sword of Orion) is a current site of lots of star formation 7
Nebula collapse spinning disk
• Gas cloud collapses, heats up, spins, flattens
• Go from a big nebula to a small spinning disk
The protostellar disk
Planets
• Planets are
A. Formed around a star as it is born
B. Caught by an adult star
C. Caught by a young star
10
Circumstellar Disks
11
Other places we see disks
The Living Star
Gravitational equilibrium
Hydrogen Fusion:
600 million tons of H into 596 million tons of He per second
Death of the Sun
Layers
15
Planetary Nebulae
• Expanding shell of gas, lit by intense UV radiation • Misnomer – they kinda look like planets
17
The Dead Heart: The White Dwarf
Planetary nebula dissipates...
1Msun = 333,000 MEarth
• Can’t be larger than 1.4 Msun
Star Lifetimes
Fates of Stars
• < 2 Msun
• > 8 Msun
Layers in the Death Throes of a High-Mass Star
• Iron is the most stable • Will not burn
• Core collapses
• Explodes
• Type II
Supernova
21
The Crab Nebula
22
One teaspoon of Neutron Star stuff weighs as much as a mountain
If more than 3Msun is left behind, gravity is too much to be held up...
23
The Sun may become a black hole
A. True
B. False
If it did
A. We would be sucked in
B. We would continue to