Take out your Famous Astronomers HW from last night AIM: Understand how stars and constellations are formed HW: Why are flames orange article Astronomy Quiz on Tuesday 4/25 Do Now: 4/19/17 Take out your Famous Astronomers HW from last night In your DO NOW section, answer the following question: What is a constellation?

What is a Star? Constellations: a pattern of stars in the sky Example 1: Orion Example 2: Ursa Major

Famous Astronomers Ptolomy Galileo Copernicus Brahe

Stars Stars are balls of gas, held together by their own gravity. Formed from gas and dust from space. Usually from a supernova explosion. Made up of mostly hydrogen and helium gases with trace amounts of other elements The glow from the star is from nuclear fusion of hydrogen into helium. Our sun is our closest star. Can range in size, brightness and temperature. When they “die”, depending upon their size they can form a white dwarf, neutron star OR black hole.

The Largest Star In the Universe You Ask?! VY Canis Majoris is in the “Big dog” constellation and it is at the end of its life. It swelled up to be a red hypergiant star with a volume of about a billion times that of the sun. If it was placed in our solar system, its surface would reach out to where the orbit of SATURN is!!!

Color and Temperature of Stars Questions: What color is our sun? 2)How many degrees K is our sun? 3)What color stars are the hottest? 4)What color stars are the coolest? yellow 6,0000K Blue Red 6

Flame Color Testing Demonstration How do scientists know what gases make up the stars? Would we be able to figure out the composition of a star if we had a list of what colors stars burn? Let’s find out….

Procedure Light burner Clean loop – first in HCl, then distilled H20. Dry it in flame until no color shows. Dip loop into test tube #1, then move into the open flame of the Bunsen burner. Record the first color you see. Repeat steps #2 and #3 for each of the numbered test tubes and then for test tube X.

Bunsen Burner Reminders Safety Always wear goggles Tie back loose hair Watch all loose papers

Record class observations in the “Flame Color” column. Bottle Strontium Chloride Barium Chloride Potassium Chloride Sodium Chloride Calcium Chloride Copper Chloride Lithium Chloride How did you determine the identity of the substance in bottle X? What might happen if these compounds were mixed?

Flame Test

BrainPOP Tim and Moby explain the Lifecycle of Stars, constellations and black holes! Black hole video 9 min