Lifecycle of the Sun www assignmentpoint com TakeAway

Lifecycle of the Sun www. assignmentpoint. com

Take-Away Points 1. 2. 3. 4. 5. 6. 7. 8. The Sun is an ordinary middle-sized star The sun creates energy by nuclear fusion in its core The visible surface of the Sun is called the photosphere A thin cool layer, the chromosphere, allows us to determine what the sun is made of A very thin but very hot outer layer is called the corona Convection in the sun is revealed by granulation Features on the sun include sunspots, prominences, spicules and faculae Disturbances on the sun affect electrical and electronic equipment on Earth www. assignmentpoint. com

The Sun • Distance: 150 million km (93 million miles) = 8. 3 light minutes • Diameter: 1. 4 million km (870, 000 miles) = 109 x Earth • Mass = 330, 000 x Earth • Bulk density = 1. 4 gm/cc • Surface temperature = 5800 K • Rotation: 25 days at equator, 34 at poles www. assignmentpoint. com

The Solar Interior • Ideal Gas Law: – Pressure x Volume is proportional to Temperature • Pressure = weight of overlying material www. assignmentpoint. com

Interior of the Sun % of Radius Temperature K Pressure (Atm) Density (gm/cc) % of Mass 100 5700 . 07 2 x 10 -7 100% 90 600, 000 2, 130, 000 0. 026 99. 8% 80 1, 360, 000 17, 000 0. 09 99% 70 2, 300, 000 66, 000 0. 2 97% 60 3, 100, 000 210, 000 0. 56 94% 50 4, 000 720, 000 1. 3 89% 40 5, 100, 000 2. 7 billion 3. 9 79% 30 6, 800, 000 11 billion 12 61% 20 9, 370, 000 43 billion 35 33% 10 13, 100, 000 130 billion 87 7. 7% 0 15, 700, 000 230 billion 154 www. assignmentpoint. com 0%

Structure of the Sun • Core: 0 -20% of radius. Energy produced by nuclear fusion • Radiative Zone: 20 -70% of radius: Energy travels as thermal radiation • Tachocline: Boundary of Radiative Zone: Exterior slips over interior • Convective Zone: Outer 30% of Sun: Energy moves by convection www. assignmentpoint. com

Core of the Sun • Energy output: 90 billion megatons/second • Energy output = 6 microwatts/kg – less than a candle • Human body outputs 1. 2 W/kg – 200, 000 times greater • By volume: Core of Sun = 0. 9 W/m 3; Human body = 1200 W/m 3. • Trying to duplicate sun’s energy output not practical on Earth; We try to use other fusion processes • Energy takes 10, 000 – 100, 000 years to reach surface www. assignmentpoint. com

Solar Energy • • • 4 H He 4 H = 4 x 1. 00794 = 4. 03176 He = 4. 002602 Difference = 0. 029158 = 0. 7% = 1/140 Converted to energy via E=mc 2 Once you get over being freaked out by Einstein, this is middle school math www. assignmentpoint. com

Solar Energy • • E=mc 2 m = kg c = m/sec = 300, 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/c 2 = 3. 8 x 1026/(300, 000)2 = 4 billion kg/sec www. assignmentpoint. com

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 www. assignmentpoint. com

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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 www. assignmentpoint. com

Layers Of The Sun www. assignmentpoint. com

Features On The Sun • • Limb Darkening Granulation Sunspots Faculae Plages: hot clouds in the Chromosphere Flares Prominences www. assignmentpoint. com

Surface of the Sun www. assignmentpoint. com

Supergranulation www. assignmentpoint. com

Supergranulation www. assignmentpoint. com

Sunspots and Faculae www. assignmentpoint. com

Sunspots, Faculae, Limb Darkening www. assignmentpoint. com

Solar Spicules www. assignmentpoint. com

Solar Prominence www. assignmentpoint. com

Solar Corona www. assignmentpoint. com

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