The Sun Awesome solar eruption Objectives Explain how

The Sun Awesome solar eruption

Objectives • Explain how the sun converts matter into energy in its core. • Compare the radiative and convective zones of the sun. • Describe three layers of the sun’s atmosphere. • Discuss how sunspots are related to powerful magnetic fields on the sun. • Contrast prominences, solar flares, and coronal mass ejections. • Describe how the solar wind can cause auroras on Earth.

The Sun’s Energy • Composition of the Sun: 76 % Hydrogen, 22% Helium, and 2 % heavy elements • The Suns’ Energy is generated by Nuclear Fusion – Extreme pressure and temperatures cause hydrogen atoms to move at up to 300 miles/sec. When they collide, they fuse together to form helium – This produces Electromagnetic energy/radiation (Visible light, UV light, X-rays, Gamma rays)

The Sun’s Energy • Every second the sun produces the equivalent amount of energy created by 100 billion one megaton bombs • Six seconds of direct solar energy would evaporate all the Earth’s oceans! • Three minutes would melt the Earth’s crust!!

The Sun’s Interior • 3 Main parts of the Sun: • Core • Radiative zone • Convective zone • The Core: • 25% of the sun’s total diameter • Temperature of about 27 million degrees F • Nuclear Fusion occurs in this layer

The Radiative Zone • Radiative Zone: zone between the core and the convective zone • 85% of the internal mass of the Sun • Temperature ranges from about 2, 000ºC to 7, 000 ºC • Energy moves outward in the form of electromagnetic waves, or radiation from the super hot interior to the cooler exterior • Just remember, energy travels by radiation in the Radiative Zone…makes sense, right? • It takes about a million years for a single photon of energy to reach the surface from the core

The Convective Zone • Convective Zone: Region between the radiative zone and the photosphere • Outer 15 % of the Suns’ Radius • The temperature of the convective zone is about 2, 000ºC • energy is carried outward by convection • Convection causes warmer areas of gas to rise to the surface and cooler areas to sink down into lower layers

The Sun’s Atmosphere • The sun’s atmosphere consists of 3 layers: • Photosphere • Chromosphere • Corona • Photosphere: the visible surface of the sun • Innermost layer of the sun’s atmosphere • Temperature is around 6, 000ºC • Sunspots, Solar Flares, and Solar Prominences are formed in this layer • Much of the energy given off from the photosphere is in the form of visible light

The Sun’s Atmosphere Reading Check What layers make up the sun’s atmosphere? The sun’s atmosphere consists of the photosphere, the chromosphere, and the corona.

The Chromosphere • Chromosphere: thin layer of the sun above the photosphere, with a reddish color • Temperature ranges from 4, 000°C to 50, 000 °C • Can be seen by the naked eye only during a solar eclipse • Corona: the outermost layer of the sun’s atmosphere • Huge region of gas with temperatures above 1, 000ºC • Layer of extremely hot ionized gas. This gas makes up the solar wind • Solar Wind: Very high temperatures enable ionized atoms to escape the Sun’s gravity • The mass lost is called the Solar Wind and consists mainly of free electrons and ions of hydrogen and helium • The solar wind flows outward from the sun to the rest of the solar system

Suns’ Chromosphere: Only visible during an eclipse

Sun’s Corona as seen through an Eclipse 12

Sunspots • Sunspot: a disturbed region of the photosphere which is cooler than its surroundings. • Appears dark because its gases are thousands of degrees cooler than the surrounding gas • May appear as single sunspots or in groups • Cause: Slower convection results in a decrease in the amount energy transferred from the core to specific regions of the photosphere • These, cooler, darker areas form sunspots

Solar Ejections • Solar ejections are events in which the sun emits atomic particles. The 3 types of solar ejections are: • Prominences • Solar flares • Coronal mass ejections

Prominences • Prominences: a loop of relatively cool, incandescent gas which extends above the photosphere – huge arches of glowing gases

Solar Ejections • Solar Flare: an explosive release of energy and the most violent of all solar disturbances. • Gigantic Outbursts of Charged particles and electromagnetic radiation (light) created when extremely hot gas spouts upward from the surface of the sun. • As charged particles pass into Earth’s upper atmosphere, they create Auroras. (Northern and Southern lights) • Solar flares release the energy stored in strong magnetic fields surrounding sunspots

Solar Flare

Solar Ejections • Coronal Mass Ejections: coronal gas ejected into space • The particles in the ejection may cause disturbances to Earth’s magnetic field • Coronal Mass Ejections have also been known to interfere with radio communications, satellites, and even cause blackouts

Actual Photo: February 6, 2007 • Coronal Mass Ejections: coronal gas ejected into space • The particles in the ejection may cause disturbances to Earth’s magnetic field Coronal Mass Ejections have also been known to interfere with radio communications, satellites, and even cause blackouts