The Sun

Our sun is a Star like all the other stars in the sky

Our Sun is an average star

Compared to Earth the Sun is Huge

Life Cycle of Stars

Energy All stars get their energy from nuclear fusion Fusion combines atoms of lighter elements into heavier elements Plasma is the fourth state of matter and is a result of the great heat and pressure This intense pressure tears atoms of hydrogen and helium apart

Albert Einstein E = mc² E = Energy M = Mass C = speed of light (186,000 mps)

The Sun’s Layers

Photosphere – the visible surface of the sun Chromosphere – the inner layer of the sun’s atmosphere. It extends thousands of kilometers

Sunspots Dark spots on the Photosphere They move from left to right across the sun The number changes from day to day This shows the Sun rotates on its axis The rate of rotation varies At the equator it is approx 25 days At the poles it is approx 34 days

Solar Wind Solar Wind – a constant stream of electrically charged particles from the corona They are mostly protons & electrons They travel at 450 kps They reach the Earth in a few days The Earth’s magnetic field shields the Earth from the Solar Wind

Solar Events Coronal Holes – a hole in the corona giving off huge amount of solar wind Solar Flares – outbursts of light from sunspots giving off large amounts of solar wind The Earth’s Magnetic Field protects the Earth from this solar wind

Solar Prominences

Auroras Auroras are caused as the solar wind passes through the Earth’s magnetic field at the poles Magnetic Storms occur when the particles from coronal holes and solar flares are added to the constant solar wind This may interrupt cell phones, radio, TV, etc.

The Dark Side of the Sun