Stars

I.Introduction A. Some ‘observations’

During the 20 th Century 1. Our Sun is not the center of our Galaxy

During the 20 th Century 1. Our Sun is not the center of our Galaxy 2. There is nothing special about our Sun - it is quite ordinary among billions of other stars.

During the 20 th Century 1. Our Sun is not the center of our Galaxy 2. There is nothing special about our Sun - it is quite ordinary among billions of other stars. 3. Our galaxy is not the only one. There are billions of other galaxies.

During the 20 th Century 1. Our Sun is not the center of our Galaxy 2. There is nothing special about our Sun - it is quite ordinary among billions of other stars. 3. Our galaxy is not the only one. There are billions of other galaxies. 4. Our existence on Earth depends upon the Sun’s stability. Both the Sun and the Earth are quite mortal, and will not exist forever.

During the 20 th Century 1. Our Sun is not the center of our Galaxy 2. There is nothing special about our Sun - it is quite ordinary among billions of other stars. 3. Our galaxy is not the only one. There are billions of other galaxies. 4. Our existence on Earth depends upon the Sun’s stability. Both the Sun and the Earth are quite mortal, and will not exist forever. 5. The Universe is expanding.

Stars I.Introduction A. Some ‘observations’ B. The expanding Universe ‘how do we know?’

Doppler Effect The Doppler Effect

The “RED SHIFT”

THE BIG BANG THEORY The Universe is Expanding Everywhere - Everything is moving away from everything else. The “RED SHIFT” Doppler Effect The Doppler Effect

THE BIG BANG THEORY The Universe is Expanding Everywhere - Everything is moving away from everything else. The “RED SHIFT” Doppler Effect The Doppler Effect HUBBLE’ LAW Edwin Hubble: HUBBLE’ LAW - Galaxies are receding in every direction. Those furthest away are moving at the fastest rate: v = H d [H = 50 km/sec per megaparsec] Megaparsec = 3.26 x 10 6 Light Years

Stars I.Introduction A. Some ‘observations’ B. The expanding Universe C. Classifying Stars

HERTZPRUNG - RUSSEL DIAGRAM A Classification of Stars And The Evolution of Stars

HERTZPRUNG - RUSSEL DIAGRAM A Classification of Stars And The Evolution of Stars Luminosity (Brightness) vs. Surface Temperature See Fig in Text

Main Sequence Red Giants Super Giants White Dwarfs Black Dwarfs

II. The Life Cycles of Stars A. The Birth of Stars

Planetary Nebula

II. The Life Cycles of Stars A. The Birth of Stars B. The Main Sequence and the Death of Stars

II. The Life Cycles of Stars A. The Birth of Stars B. The Main Sequence and the Death of Stars 1. Our Sun Hydrogen burning (fusion) H + H  He

II. The Life Cycles of Stars A. The Birth of Stars B. The Main Sequence and the Death of Stars 1. Our Sun Hydrogen burning (fusion) H + H  He 1 H H 2 = 2 He 3 + neutron + Energy

Hydrogen [H] is fusing to Helium [He] which accumulates in the core.

No Fusion in the core: results in less pressure pushing outward

Hydrogen [H] is fusing to Helium [He] which accumulates in the core. No Fusion in the core: results in less pressure pushing outward Greater mass concentration: Gravitational collapse inward which causes increased (100x) Hydrogen fusion of sun

Hydrogen [H] is fusing to Helium [He] which accumulates in the core. No Fusion in the core: results in less pressure pushing outward Greater mass concentration: Gravitational collapse inward which causes increased (100x) Hydrogen fusion of sun This event causes rapid expansion of the outer layers into a Red Giant.This causes a cooling of the outer portion of sun.

Helium [He] continues to accumulate at rapid rate in core until 100 million degrees is reached. Additional burning………

Helium [He] continues to accumulate at rapid rate in core until 100 million degrees is reached. Additional burning……… Helium burning (fusion) He + He + He  C

Helium [He] continues to accumulate at rapid rate in core until 100 million degrees is reached. Additional burning……… Helium burning (fusion) He + He + He  C 2 He He He 4 = 6 C 12 + Energy

Carbon accumulates in core continually…… ……. raising pressure, temperature and mass.

Carbon accumulates in core continually raising pressure, temperature and mass. Gravitational Forces Take over and Red Giant collapses to size of planet earth. Most H and He has been consumed and converted to Carbon

Carbon accumulates in core continually raising pressure, temperature and mass. Gravitational Forces Take over and Red Giant collapses to size of planet earth. Most H and He has been consumed and converted to Carbon Black Dwarf White Hot core of Carbon remains [White Dwarf] which will cool to a Black Dwarf

Carbon accumulates in core continually raising pressure, temperature and mass. Gravitational Forces Take over and Red Giant collapses to size of planet earth. Most H and He has been consumed and converted to Carbon White Hot core of Carbon remains [White Dwarf] which will cool to a Black Dwarf One Teaspoon weighs about 2000 pounds

II. The Life Cycles of Stars A. The Birth of Stars B. The Main Sequence and the Death of Stars 1. Our Sun 2. Stars ~4x mass of our Sun

a. Red Giant collapses

2. Stars ~4x mass of our Sun a. Red Giant collapses b. Fusion continues He + He + He  C

2. Stars ~4x mass of our Sun a. Red Giant collapses b. Fusion continues He + He + He  C C  O  Si  Fe

2. Stars ~4x mass of our Sun a. Red Giant collapses b. Fusion continues He + He + He  C C  O  Si  Fe c. IMPLOSION!!!!!!

2. Stars ~4x mass of our Sun a. Red Giant collapses b. Fusion continues He + He + He  C C  O  Si  Fe c. IMPLOSION!!!!!! d. Supernova develops

Supernova

2. Stars ~4x mass of our Sun a. Red Giant collapses b. Fusion continues He + He + He  C C  O  Si  Fe c. IMPLOSION!!!!!! d. Supernova develops e. New Elements are created

2. Stars ~4x mass of our Sun a. Red Giant collapses b. Fusion continues He + He + He  C C  O  Si  Fe c. IMPLOSION!!!!!! d. Supernova develops e. New Elements form f. Neutron Stars and Pulsars

NEUTRON STAR - NEUTRON STAR - Electrons Driven into Protons of the Nucleus by unstoppable gravity

km -Very Rapid Rotation - 1 Trillion Times Denser Than Sun - Not an element - Magnetic Field

NEUTRON STAR - NEUTRON STAR - Electrons Driven into Protons of the Nucleus by unstoppable gravity km -Very Rapid Rotation - 1 Trillion Times Denser Than Sun - Not an element - Magnetic Field PULSAR - Neutron Star with strong electromagnetic beam, and rapid rotation.

PULSARS

II. The Life Cycles of Stars A. The Birth of Stars B. The Main Sequence and the Death of Stars 1. Our Sun 2. Stars ~4x mass of our Sun 3. Mega Stars (~6x mass of our Sun)

II. The Life Cycles of Stars 3. Mega Stars (~6x mass of our Sun) a. Same progression as before, but….

BLACK HOLE

BLACK HOLE - The Extreme- Only from Super Giants – Similar to Neutron Star but collapse continues to infinite Large Mass and Small Size. - Escape Velocity of Light Exceeded.

IN SUMMARY…..

Stars III. In the beginning……

COSMOLOGY COSMOLOGY = Studies the beginning and the ending of cosmic time.

BIG BANG BIG BANG : 15 to 20 Billion Years Ago

COSMOLOGY COSMOLOGY = Studies the beginning and the ending of cosmic time. BIG BANG BIG BANG : 15 to 20 Billion Years Ago Sec after The Big Bang TEMPERATURE: K

COSMOLOGY COSMOLOGY = Studies the beginning and the ending of cosmic time. BIG BANG BIG BANG : 15 to 20 Billion Years Ago Sec after The Big Bang TEMPERATURE: K 0.1 Sec: 100 billion K

COSMOLOGY COSMOLOGY = Studies the beginning and the ending of cosmic time. BIG BANG BIG BANG : 15 to 20 Billion Years Ago Sec after The Big Bang TEMPERATURE: K 0.1 Sec: 100 billion K 1.0 Sec: 10 billion K [ Protons & Neutrons can begin to form]

COSMOLOGY COSMOLOGY = Studies the beginning and the ending of cosmic time. BIG BANG BIG BANG : 15 to 20 Billion Years Ago Sec after The Big Bang TEMPERATURE: K 0.1 Sec: 100 billion K 1.0 Sec: 10 billion K [ Protons & Neutrons can begin to form] 1 Million Years: Temperatures drop where Electrons and Nuclei form atoms

BEFORE THE BEGINNING OF TIME ? Matter, Time, Space, Energy A “COSMIC EGG” ? Beyond Scope of Science