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Delve into the fascinating properties of the Sun, from its core to the corona. Explore energy generation mechanisms, main regions, solar wind composition, and solar cycle impact. Unravel the solar wind's role in shaping the magnetosphere and the potential disruptions caused by coronal mass ejections.
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Nada Al-Haddad KU Leuven THE SUN SHINE 2011 1
OUTLINES • Properties • Core • Radiative Zone • Convective Zone • Photosphere • Chromosphere • Corona 2
Properties • Main Sequence G star • M⨀= 2x1030 kg • R⨀ = 7x108 m = 7x105 km • L⨀ = 3.9x1026 W (Solar Constant = 1350 W/m2) • Mean Density = Mass/Volume = M/((4/3)πR3)= 1400 kg/m3 = 1.4 g/cm3 3
Main Regions The core Energy generation through nuclear burning 5
Main Regions The core Energy generation through nuclear burning Adapted from George Rafflet at Jigsaw, India 2007 6
Main Regions Radiative Zone Energy transportation through Radiation 7
Main Regions Convective Zone Energy transportation through Convection 8
Main Regions Convective Zone Energy generation through nuclear burning 9
Photosphere • Source of Photons • 6000 K Features: • SUNSPOTS • Low temperature in the photosphere ~ 4780 K • Intense magnetic field • Days-Weeks 10
Chromosphere • 1600 Km • 10^-4 the intensity of the photosphere • Temperature increase 4400-100000 K • He II, Fe II, Si II, Cr II and Ca II Features: • Flares • Prominences 11
Corona 5273 K • Very high temperature • Visible at total eclipse • No well defined outer boundary • Low density Features: 2,000,273 K • Coronal holes • Dark in X-ray and EUV • Low density • High speed Solar wind 13
Solar wind • Constant stream of charged particles (Plasma) from Sun to beyond pluto ( 5900 million km) • 95% protons & electrons, 5% isotopes: helium-3, helium-4, neon-20, neon-21, neon-22, and argon-36 • Average speed 450 km/s • Average Density4 atoms/cm3 • Shapes the magnetosphere 14
Solar wind • Constant stream of charged particles (Plasma) from Sun to beyond pluto ( 5900 million km) • 95% protons & electrons, 5% isotopes: helium-3, helium-4, neon-20, neon-21, neon-22, and argon-36 • Average speed 450 km/s • Average Density4 atoms/cm3 • Shapes the magnetosphere 15
Solar Cycle 16
Solar Cycle 17
Coronal Mass Ejections • explosions in the Sun's corona • huge bubbles of gas threaded with magnetic field lines • 10^6 K • A lot of material is thrown out into the solar wind • CME's can seriously disrupt the Earth's environment 18
Dank U Wel! 19