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: SolSize: 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 inwardhttp://www.youtube.com/watch?v=R5_9Gi7w19YThe Sun (Sol), became a star when the two

forces balanced out

Stellar LeftoversEverything 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 kmMass: 1.0014 x the mass of the Sun (including the

Sun)Age: 4.6 billion years old

After our star formedRemember the pepper!Swirling represented gravitySoap represented the aftermath of fusion

The Star in the CenterThe Stellar Nebular Accretionary Disk forms

around the star after it stabilizesHeavy 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 outsideFrozen light weight gasses (Methane, Ammonia,

Hydrogen, Helium, and others) accreted to form the outer gas planets

Our GalaxyName: Milky WaySize: 100,000 L.Y. (light years) acrossAge: 13.2 billion years oldMass: approximately 1.25 trillion x the mass of the

Sun

Formation of GalaxiesThe same processes we saw in the pepper and

planetary systems cause galaxies to formGravity 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