Stars and Planetary Systems and Galaxies, Oh My!!!

Goals:  You will understand the formation of stars, planetary systems, and galaxies  You will generate a foldable that describes the three processes

What is a Star?  Any of the celestial bodies visible at night from Earth as relatively stationary, usually twinkling points of light.  A self-luminous celestial body consisting of a mass of gas held together by its own gravity in which the energy generated by nuclear reactions (fusion) in the interior is balanced by the outflow of energy to the surface, and the inward-directed gravitational forces are balanced by the outward-directed gas and radiation pressures.  Something regarded as resembling such a celestial body.

Our Star…  Named: Sol  Size: Average size star (1,391,000 km in diameter)  Age: Approx. 4.6 Billion Years (middle aged)  Mass: 1.989x10^30 kg  The closest star and the only one we can study the surface structures of.

What formed our Star (Sol)…  Gravity inside clouds of gas and cosmic dust compressed until Hydrogen fusion occurred.  Energy from fusion pushed outward and gravity pulled inward   The Sun (Sol), became a star when the two forces balanced out

Remember the pepper in the water!!

Stellar Leftovers  Everything that is left after a star forms joins the stellar nebular accretionary disk  This is the material that planets will be made of  Light weight materials are pushed out and heavy ones stay put

Our Planetary System…  Name: Solar System (because our star is named Sol)  Diameter: approx. 4.5 billion km  Mass: x the mass of the Sun (including the Sun)  Age: 4.6 billion years old

After our star formed  Remember the pepper!  Swirling represented gravity  Soap represented the aftermath of fusion

The Star in the Center  The Stellar Nebular Accretionary Disk forms around the star after it stabilizes  Heavy materials (metallic and non-metallic solid elements, Oxygen, Nitrogen, and other heavy gasses) accrete in the same manner to form the solid planets (rocky planets)

Gasses to the outside  Frozen light weight gasses (Methane, Ammonia, Hydrogen, Helium, and others) accreted to form the outer gas planets

Our Galaxy  Name: Milky Way  Size: 100,000 L.Y. (light years) across  Age: 13.2 billion years old  Mass: approximately 1.25 trillion x the mass of the Sun

Formation of Galaxies  The same processes we saw in the pepper and planetary systems cause galaxies to form  Gravity pulls stars and other materials into the center of the galaxy until enough mass accretes to form the black hole  Everything that is left, orbits around the black hole