The Sun NOTES.doc

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IV. SUN

A) Vital Statistics of Sun:

1) Composition (approximate) a) by mass: Hydrogen = 70%, Helium = 28%, 75 other elements =2%. b) by amount of atoms: H = 90%, He = 8%

2) Size: 109 times the diameter of earth / 1.25 million times earth’s material.

3) Age = about 5 billion years w/ a life span of 10 billion years.

4) Rotation takes about 1 month.

5) End of the Sun = Red Giant to White Dwarf to Black Dwarf. B) Source of the Sun’s energy = Nuclear Fusion.

1) Nuclear Fusion – the combining of lighter nuclei particles into heavier nuclei particles under very high temperature (27 million o_{F or10-15 million K) and very high pressure} (200-340 billion times earth’s surface pressures).

a) Fusion of elements smaller than Iron (Atomic mass 56) releases energy.

b) Fusion involving elements larger than Iron need energy. 2) Fusion on Stars.

a) Small mass stars (less than 0.5 Sun-masses) – The only Fusion process is Hydrogen converting to Helium.

b) Sun-like mass stars – Fusion involves: Hydrogen to Helium, then Helium to Carbon. (3 He4 __C12₎

c) Stars up to 8-solar masses – Fusion involves: Hydrogen to Helium, Helium to Carbon, Carbon to Neon, Neon to Oxygen

d) Very massive stars – Fusion involves:

Hydrogen -> Helium -> Carbon - > Neon -> Oxygen -> Silicon – Iron

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3) Sun’s Fusion Equation:

4)

During fusion, since 4 Hydrogen atoms have more mass (4.032 AMU) than the one Helium atom (4.003 AMU) that is produced, the “lost” mass is converted into ENERGY.

5) Every second our Sun’s core uses 700 million tons of Hydrogen as fuel and producing 5 million tons of pure energy. It takes about 1 million years for the energy to get from the sun’s core to the sun’s surface.

6) How do we calculate the amount of energy that comes from a “loss” of mass during nuclear fusion?

where . . .

Speed of light

(approximates)

4 Hydrogen atoms  Helium + Energy

High Pressure High Temperature

He + Energy

H

+

Each H atom has a mass of 1.008 AMU. So, 4 H = mass of 4.032 AMU

During a Nuclear Fusion reaction there is a “loss” of .029 AMU.

This “lost” mass is converted to ENERGY.

Answer:

E=

mc

2

E= energy that is produced m = mass amount (in kg)

c = speed of light (3 x 108

meters/second)

Combined mass of 4.032 AMU

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3 x 108 _{meters/second (= “c” light speed}

constant)

 186,000 mi/sec (about 7.5 trips around the earth in 1 second)

11,181,000 mi/min (over 23 trips to the moon and back in 1 minute)

670,878,000 mph (speed of sound = 760 mph) (about 3.5 round trips to the sun and back in 1 hour)

1.61 billion miles/day

5.88 trillion miles/year = 1 light year

19.2 trillion miles = 1 parsec = 3.26 l.y

. . . to think. . .

+ Sun’s light reaches earth in 8.5 minutes.

+ Moon’s light reaches earth in1.2 seconds.

+Nearest star to us is about 4.3 light years away.

+Milky Way Galaxy is 5000 l.y. wide by100,000 l.y. long.

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Sun's Structure.ppt

C) Sun’s Structure 1) Solar Interior

a) Core

b) Radiation Zone c) Convection Zone 2) Photosphere

3) Chromosphere 4) Corona

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Unit – Sun & Light

I. SUN

A) Vital Statistics of Sun:

“The Sun - Amazing Documentary” - Discover (44 min):

https://www.youtube.com/watch?v=C2FETG7tCF0

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I. SUN

1) Composition (approximate)

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IV. SUN

1) Composition (approximate)

a) by mass:

Hydrogen = 70%,

Helium = 28%,

75+ other elements =2%.

b) by amount of atoms:

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IV. SUN

2) Size:

109 times the

diameter of earth / over 1.3

million times earth’s

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OVER 100 earths would fit across the length of the sun

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IV. SUN

3) Age =

about 4.5 billion

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IV. SUN

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4) Rotation takes about 1 month.

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Planetary Nebulae from stars

with masses similar to the

Sun’s:

Ring Nebula

Blue Snowball

Nebula

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5) End of the Sun = Red Giant to White Dwarf to Black Dwarf.

B) Source of the Sun’s energy

= Nuclear Fusion.

How Fusion Powers the Sun… Sci Channel (2 min)

https://www.youtube.com/watch?v=W1ZQ4JBv3-Y

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B) Source of the Sun’s energy = Nuclear Fusion.

1) Nuclear Fusion –

the

combining of

lighter nuclei

particles

into

heavier nuclei

particles

under very high

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1) Nuclear Fusion –

the

combining of lighter nuclei particles

into heavier particles under very

high temperatures

(27 million

o

F

or 10-15 million K)

and very

high pressure

(200-340

billion times earth’s surface

pressures)

.

Fusion vs Fission … Scientific America (2:30)

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B) Source of the Sun’s energy = Nuclear Fusion.

1) Nuclear Fusion – the combining of lighter nuclei particles into heavier nuclei particles under very high temperature (27 million o_{F or10-15 million}o_{C) and very high pressure} (200-340 billion times earth’s surface pressures).

a) Fusion of elements

smaller than Iron

(Atomic mass 56)

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b) Fusion involving

elements larger than

Iron

needs energy

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b) Fusion involving elements larger than Iron need energy.

2) Fusion on Stars.

a) Small mass stars

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b) Fusion involving elements larger than Iron need energy. 2) Fusion on Stars.

a) Small mass stars

(less than 0.5

Sun-masses) –

The only

Fusion process is

Hydrogen converting

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a) Small mass stars (less than 0.5 Sun-masses) – The only Fusion process is Hydrogen converting to Helium.

b) Sun-like mass stars –

Fusion involves:

Hydrogen to Helium

,

then

Helium to Carbon

.

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b) Sun-like mass stars – Fusion involves: Hydrogen to Helium, then Helium to Carbon. (3 He4 __C12₎

c) Stars up to 8-solar

masses – Fusion

involves:

Hydrogen to Helium

,

Helium to Carbon

,

Carbon to Oxygen,

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c) Stars up to 8-solar masses – Fusion involves: Hydrogen to Helium, Helium to Carbon, Carbon to Oxygen, Oxygen to Neon

d) Very massive stars –

Fusion involves:

Hydrogen

->

Helium

->

Carbon

- >

Oxygen

->

Neon

->

Magnesium

–>

Silicon

–>

Iron

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Hydrogen -> Helium -> Carbon - > Neon -> Oxygen -> Silicon – Iron

e) Elements bigger

than

Iron

are made in

Supernova

explosions, Neutron

Stars Colliding …. Up

to Plutonium (Pu).

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Hydrogen -> Helium -> Carbon - > Neon -> Oxygen -> Silicon – Iron

e) Elements bigger than Iron are made in Supernova explosions.

3) Fusion Equation:

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3) Fusion Equation:

Nuclear Fusion equation (3 min):

https://www.youtube.com/watch?v=Cb8NX3HiS4U

Taylor Wilson (teenager): (3:23): TED: Build a Nuclear Fusion Reactor: https://www.youtube.com/watch?v=9B0PaSznWJE

High Pressure

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On Sun-sized stars Proton-Proton

Fusion dominates.

https://en.wikipedia.org/wiki/Nuclear_fusion

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3) Fusion Equation:

4)

During fusion, since 4 Hydrogen

atoms have more mass (4.032 AMU)

than the one Helium atom (4.003

AMU) that is produced, the “lost”

mass is converted into ENERGY.

High Pressure

High Temperature

He + Energy

H

+

Each H atom has a mass of 1.008 AMU. So, 4 H = mass of 4.032 AMU

During a Nuclear Fusion reaction there is a “loss” of .029 AMU.

This “lost” mass is converted to ENERGY.

Combined mass of 4.032 AMU

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4) During fusion, since 4 Hydrogen atoms

have more mass (4.032 AMU) than the one

Helium atom (4.003 AMU) that is produced,

the “lost” mass is converted into ENERGY.

5) Every second our Sun’s

core:

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4) During fusion, since 4 Hydrogen atoms have more mass (4.032 AMU) than the one Helium atom (4.003 AMU) that is produced, the “lost” mass is converted into ENERGY.