The “Life” of Non-living Stars By Erin Belluomini

Why do stars look different colors in the night sky? Stars are different colors Colors indicates the temperature of the star Red stars are the coolest Blue stars are the hottest

Fascinating Examples Orion is a well-known winter constellation Orion contains a large red star known as Betelgeuse Orion also contains a blue star known as Rigel Betelgeuse and Rigel differ in their temperatures too

From what elements are stars created? Studying light from a star can tell us what elements are in stars A continuous spectrum shows all the colors when white light passes through a prism Elements emitted from stars do not show all the colors of the spectrum The colors that get absorbed tell scientists from what elements the star is made

Common Elements of Stars Hydrogen and Helium are the most abundant elements in stars Stars contain other trace elements Carbon, nitrogen and oxygen are the most common

How do scientists classify stars? Originally stars were classified by the elements they contained Astronomers created system based on brightness…absolute magnitude Positive #s are dim, negative #s are bright Stars are classified by temperature

Why do we see different constellations throughout the year? Earth revolves around sun Earth’s tilt and revolution cause season’s Earth faces a different part of sky each season A different constellation is seen at different times of the year

Motion of and Distance to Stars Stars closer to Earth seem to move Stars further away seem to stay in one place Known as parallax Parallax used to calculate actual distances to stars Distance measured in light-years A light-year is the distance light travels in one year….very fast!

Our Sun’s Color and Classification Our sun is Earth’s closest star Our sun’s color is yellow Our sun’s temperature is 6000 C Hydrogen, Helium, Calcium and other heavier elements make up our sun Our sun is a class G star Our sun is about +4.8 in absolute magnitude

Do stars “live” forever? Stars do not live forever Stars can exist for billions of years Stars get different classifications as they age To stay alive, stars must generate energy through nuclear fusion

Nuclear Fusion How the sun generates energy Process where two hydrogen nuclei fuse to form helium The beginning of a stars life Click to view video clip!

The Life Cycle of Stars Stars begin life as a ball of gas and dust Temperatures reach 10,000,000 C Nuclear Fusion begins This stage known as a Protostar

Main Sequence Main Sequence is the second and longest stage of a star’s life Hydrogen continues to fuse into helium Size of star changes very little during this stage

Giants and Supergiants Giants and Supergiants result when a star uses all the hydrogen in its core Star grows very large and cools

The H-R Diagram An H-R Diagram Shows relationship between surface temperature and absolute magnitude

Massive Stars Use their hydrogen much more quickly than stars like our sun. Generate more energy but have shorter lives. Meet dramatic deaths as Supernova explosions! Become neutron stars, pulsars and maybe black holes.

Our Sun’s Age Our Sun was born from a solar nebula. Our Sun is about half way through it’s life cycle. Our Sun will not live forever! How will our Sun die? The Click of Death

Why We Study Stars The structure and composition of the universe can be learned by studying stars and galaxies and their evolution. Understanding the properties of stars provides us with an understanding of our sun, which is a star! The properties of the sun affect Earth directly, so it is important to know them.

Fun Facts The brightest star discovered is at least 150 times as large and probably 40 million times as bright as our sun! (Break out those sunglasses)! Sir Isaac Newton was the first to discover that white light is composed of different colors!

Comprehension Question 1) What are the two elements that commonly make up stars? a) Hydrogen (H) and Oxygen (O) b) Hydrogen (H) and Helium (He) c) Helium (He) and Nitrogen (N) d) Hydrogen (H) and Nitrogen (N)

Congratulations you are a Sun God or Goddess! Correct! b) Hydrogen and Helium are the most common and abundant elements in stars! Congratulations you are a Sun God or Goddess!

Incorrect! Try again! Remember that stars undergo nuclear fusion which means one element fuses to become another! Much energy is released in the process! Hint: What two elements are close enough to each other on the periodic table to be able to undergo nuclear fusion.

Comprehension Question 2) What will be the next stage of our sun’s life cycle? A white dwarf A pulsar A red giant A protostar

Correct Again! Our star will become a red giant once all of it’s hydrogen in its core is used, its helium has begun to fuse and the center of the star shrinks. The Sun will grow very large and will cool down! You are definitely a “STAR” student!

Incorrect! Remember that currently our star is a main-sequence, average size, yellow star!

Works Cited

My vacation Look at this sunset!