The Lifecycle of Stars and the Sun

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2. The sun creates energy by nuclear fusion in its core

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Solar Energy

E=mc2

m = kg

c = m/sec = 300,000,000

E = joules (one Watt = 1 J/sec)

Sun’s energy output = 3.8 x 1026 W

How much mass is that per second?

m = E/c2 = 3.8 x 1026/(300,000,000)2 = 4 billion kg/sec

2. The sun creates energy by nuclear fusion in its core

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Solar Energy

Sun converts 4 billion kg of matter to energy every second

Matter conversion = 1/140 of original mass

Sun converts 560 billion kg of H to He (5.6 x 1011 kg) every second

Mass of Sun: 2 x 1030 kg

2 x 1030 kg/ 5.6 x 1011 kg/sec = 3.6 x 1018 sec = 114 billion years

2. The sun creates energy by nuclear fusion in its core

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The Sun We Can See

Photosphere: The Visible Disk

More transparent than air

We can see a couple of hundred kilometers deep

Chromosphere

Thin cooler atmosphere

How we know what stars are made of

Corona

Very thin but very hot

Why so hot is a mystery

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Layers Of The Sun

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Features On The Sun

Limb Darkening

Granulation

Sunspots

Faculae

Plages: hot clouds in the Chromosphere

Flares

Prominences

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Surface of the Sun

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Supergranulation

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Supergranulation

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Sunspots and Faculae

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Sunspots, Faculae, Limb Darkening

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Solar Spicules

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Solar Prominence

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Solar Corona

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