_________________at the centre of our solar system. The Sun Grade 9 Science The Sun _________________at the centre of our solar system. _________________Km in diameter (110x the diameter of the Earth). It is our closest star and the ___________________________________________________.

Astronomy Intro Grade 9 Science Sun’s Importance Provides ________________________________________________________ Its ______________________________keeps us in our steady state orbit.

Astronomy Intro Grade 9 Science Nuclear Fusion is: ________________________________________________________________________________________ This happens because the temperature and pressure in the sun is so great that 2 hydrogen nuclei fuse together to form a helium nucleus. This produces heat, light, and energy.

Astronomy Intro Grade 9 Science Structure of the Sun Core: ____________________ Photosphere: ________________________________________ Chromosphere: Solar Flares ____________________________________________________________ The Sun has a very dense core (150 times the density of water on Earth) in which the thermonuclear reactions take place. The core is responsible for generating all of the Sun’s heat. The core extends to about 0.2 solar radii. Next is the radiative zone from about 0.2 to 0.7 radii. Here the material is hot and dense enough that the thermal radiation is sufficient to transfer the intense heat of the core outward. Next is the convective zone from about 0.7 to 1.0 solar radii. Here the material is neither dense nor hot enough to transfer the heat energy of the interior outward via radiation. Instead, thermal convection occurs as thermal columns carry hot material to the surface of the Sun.

Astronomy Intro Grade 9 Science Structure of the Sun Corona: ____________________________________________________________________________________________________ The Sun has a very dense core (150 times the density of water on Earth) in which the thermonuclear reactions take place. The core is responsible for generating all of the Sun’s heat. The core extends to about 0.2 solar radii. Next is the radiative zone from about 0.2 to 0.7 radii. Here the material is hot and dense enough that the thermal radiation is sufficient to transfer the intense heat of the core outward. Next is the convective zone from about 0.7 to 1.0 solar radii. Here the material is neither dense nor hot enough to transfer the heat energy of the interior outward via radiation. Instead, thermal convection occurs as thermal columns carry hot material to the surface of the Sun.

Astronomy Intro Grade 9 Science Structure of the Sun Solar Prominence: Large sheets of flaming hydrogen. _________________________________ Sunspots: _________________________ the sun’s surface where local magnetic fields push away hot material from the photosphere The Sun has a very dense core (150 times the density of water on Earth) in which the thermonuclear reactions take place. The core is responsible for generating all of the Sun’s heat. The core extends to about 0.2 solar radii. Next is the radiative zone from about 0.2 to 0.7 radii. Here the material is hot and dense enough that the thermal radiation is sufficient to transfer the intense heat of the core outward. Next is the convective zone from about 0.7 to 1.0 solar radii. Here the material is neither dense nor hot enough to transfer the heat energy of the interior outward via radiation. Instead, thermal convection occurs as thermal columns carry hot material to the surface of the Sun.

Astronomy Intro Grade 9 Science It also emits charged particles called _____________. Earth is protected from these solar winds by its ___________________________________________When charged particles do rain through into the Earth's atmosphere, they interact with gases that causes the particles to emit light.

Astronomy Intro Grade 9 Science This light is most visible at ______________________________________________________________________________________________________

Astronomy Intro Grade 9 Science The Sun’s Fate Once all of the hydrogen is used up there will not be any more energy. The Sun has been active for __________________________________and it is estimated that it will continue to produce energy for_________________________________________________________________