The Structure of the Sun Chapter 29-1 The Structure of the Sun

Fire and Sun For years people thought the Sun’s energy came from fire. Over the last 100 years we have found it’s not really the case.

Composition of the Sun Light is broken up into a spectrum. Spectrograph

Using this info: Determines temperature, pressure, density of gas

Can match spectra lines of elements on Earth to those from Sun

Elements in the sun Hydrogen and Helium 75% hydrogen 24% helium 1% trace of all other elements

Nuclear Fusion Nuclei of small atoms combine to form more massive atoms Hydrogen atoms Releases energy

The Final Product The fusion of Hydrogen produces Helium nuclei Energy that is released causes light and heat

Mass into Energy Einstein E=mc2 Energy = mass x speed of light squared Speed of light = 300,000 km/s

Einstein Using his equation astronomers were able to explain the huge quantities of energy produced by the sun. 600 million tons of hydrogen is changed into helium every second The suns light reaches earth in 8 minutes

Sun’s Interior Studies of sun’s motion help scientists to hypothesis the structure

Core 15,000,000 C 27,000,000 F No liquid or solid can exist at this temperature Ionized gas (plasma) Extreme pressure

Pressure and temperature cause atoms to fuse

Radiative Zone Energy moves out from the core 2,000,000 – 7,000,000 C Energy moved by radiation Electromagnetic waves

Convection Zone 2,000,000 C 3,600,000 F Energy moved by convection Matter Energy transferred as gases rise and sink

Atmosphere Upper most layers: Photosphere Chromosphere Corona

Photosphere “Sphere of Light” Energy in the form of visible light Sun spots – cooler dark areas

Chromosphere “Color sphere” Thin layer that glows red

Corona “Crown” Ions (charged particle) escape into space Make up solar wind that flows out into space