Finish the activity from yesterday CORRECTLY glue the planets

Goals for Today’s Lesson Planets Order Classification Stars Nebular Theory Classification Star Life Cycle

Classifying Planets Mercury Venus Earth Mars Jupiter Uranus Neptune Pluto Planet Classified: Location Inner outer Composition Terrestrial (“solid”) gas Size Inferior superior

Sun = gravity and heat! Classify Planets Inner Outer Small Dense (rocky) Solid surface No or few moons Warm or HOT temperature Gas, giants Low density Rings (satellites) Multiple moons Cooler or COLD temperature Sun = gravity and heat!

Stars and Galaxies Life Cycle of a Star!!

Current night sky over Phoenix, AZ Ancient Greeks and Roman observed “Patterns in the Sky” These patterns were called constellations

Wait What are Stars? A star is a luminous (shiny) ball of gas Made mostly hydrogen and Helium dust held together by its own gravity.

Nebular Theory Nebular = large cloud, dust A star is BORN!!! Nebular becomes so dense and HOT nuclear fusion occurs. Nuclear fusion = nucleus of atoms are fusing (melting together) A star is BORN!!!

STARS AND GALAXIES Classification Characteristics: 1. Color 2 STARS AND GALAXIES   Classification Characteristics: 1. Color 2. Temperature 3.Size 4. CoMpOsiTiOn (elements) 5. Brightness

Classified as G2V Hot Cold G for where it falls on the color spectrum 0-9 to show how far off it’s color is on the O-M scale I-V to show it “luminosity” shiny!! And size Main sequence are “dwarf” or small stars that aren’t as bright Hot Cold

This Diagram---shows the life cycle of stars supergiants Main sequence giants Absolute magnitude White dwarfs temperature

O, B, A, F, G, K, and M... (Oh Be A Fine Guy Kiss Me) and for you guys: Oh Be A Fine Girl Kiss Me!!

Star, meaning it’s smaller than a normal star. Our sun is a “main sequence” Star, meaning it’s smaller than a normal star. And is in the 2nd stage of a star’s life cycle.

Waves for Stars Scientists use Spectroscopes to study the spectra (wavelength) a star emits The instrument spreads light into different wavelengths

What does the color of a star tell us? How the star is moving The temperature of the star The size of the star! The stage the star is in, in the Star Life Cycle

Star Life Cycle Stars are mainly hydrogen and helium. 1. (In a star) When hydrogen fuses to helium it runs out of energy [heat] 2. The core of the star becomes unstable and begins to expand, cool, and turn red How a black hole is formed The core of a massive star that has more than roughly 3 times the mass of our Sun after the explosion will do something quite different. The force of gravity overcomes the nuclear forces which keep protons and neutrons from combining. The core is thus swallowed by its own gravity. It has now become a black hole which readily attracts any matter and energy that comes near it.

Depending on the original mass of the star Average Star (sun) Helium core turns to carbon and collapses The outer layers are expelled (BOOM!) The core remains and looks white Massive star (huge) The unstable red core grows bigger MASSIVE EXPLOSION Leaving either An extremely dense star OR Black hole

Grab the Star Life Cycle worksheet Color it Attempt to place the Star life cycle in order based off class notes

Main Sequence (Small star) Star Life Cycle Were you right? Now match the description words in the chart to your worksheet Nebular Main Sequence (Small star) Red Giant White Dwarf Planet Massive Star Super Red Giant Super Nova Neutron Star Black Hole

Why do you care? The sun is the basis to OUR existence! It also has a life cycle that is going to end one day!! Unless some brave astronomer finds a solution!

Path of a star much larger than our sun A star starts to die when hydrogen runs low: Giant: A star cools as it expands and starts to glow red. Giants can be more than 10 times larger than the sun. White dwarf: outer layers escape into space, the star collapses into a dense hot, dim star smaller than Earth. Path of a star much larger than our sun Path of our Sun

Massive Stars die explosively!! Supergiant: Massive stars become larger than giants as they leave the main sequence….they can be 100 to 1,000 times larger than the sun. Supernova: the explosion of a supergiant Neutron Star: a small dense ball of neutrons that spin after a supernova explosion Black Hole: the remnants of a supernova that are contracted even more than a neutron star… it is so dense light cannot escape from it.

Can you spot the supernova? These are before-and-after images of a recent supernova event (Supernova 2005cs) in the galaxy M51. Can you spot the bright supernova in the after (right) that wasn’t visible before? Images used with permission. ©2005-2007 by R. Jay GaBany http://www.cosmotography.com