the “life” of non-living stars by erin belluomini
TRANSCRIPT
The “Life” of Non-living The “Life” of Non-living StarsStars
By Erin BelluominiBy Erin Belluomini
Why do stars look different colors in Why do stars look different colors in the night sky?the night sky?
Stars are different colorsStars are different colorsColors indicates the temperature of the Colors indicates the temperature of the
starstarRed stars are the coolestRed stars are the coolestBlue stars are the hottestBlue stars are the hottest
Fascinating ExamplesFascinating Examples
Orion is a well-known winter constellationOrion is a well-known winter constellationOrion contains a large red star known as Orion contains a large red star known as
BetelgeuseBetelgeuseOrion also contains a blue star known as Orion also contains a blue star known as
RigelRigelBetelgeuse and Rigel differ in their Betelgeuse and Rigel differ in their
temperatures tootemperatures too
From what elements are stars From what elements are stars created?created?
Studying light from a star can tell us what Studying light from a star can tell us what elements are in starselements are in stars
A continuous spectrum shows all the A continuous spectrum shows all the colors when white light passes through a colors when white light passes through a prismprism
Elements emitted from stars do not show Elements emitted from stars do not show all the colors of the spectrum all the colors of the spectrum
The colors that get absorbed tell scientists The colors that get absorbed tell scientists from what elements the star is madefrom what elements the star is made
Common Elements of StarsCommon Elements of Stars
Hydrogen and Helium are the most Hydrogen and Helium are the most abundant elements in starsabundant elements in stars
Stars contain other trace elementsStars contain other trace elementsCarbon, nitrogen and oxygen are the most Carbon, nitrogen and oxygen are the most
commoncommon
How do scientists classify stars? How do scientists classify stars?
Originally stars were classified by the Originally stars were classified by the elements they containedelements they contained
Astronomers created system based on Astronomers created system based on brightness…absolute magnitudebrightness…absolute magnitudePositive #s are dim, negative #s are brightPositive #s are dim, negative #s are bright
Stars are classified by temperatureStars 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 StarsMotion of and Distance to Stars
Stars closer to Earth seem to moveStars closer to Earth seem to move Stars further away seem to stay in one placeStars further away seem to stay in one place Known as parallaxKnown as parallax Parallax used to calculate actual distances to Parallax used to calculate actual distances to
starsstars Distance measured in light-yearsDistance measured in light-years A light-year is the distance light travels in one A light-year is the distance light travels in one
year….very fast!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?Do stars “live” forever?
Stars do not live foreverStars do not live foreverStars can exist for billions of yearsStars can exist for billions of yearsStars get different classifications as they Stars get different classifications as they
ageageTo stay alive, stars must generate energy To stay alive, stars must generate energy
through nuclear fusionthrough nuclear fusion
Nuclear FusionNuclear Fusion
How the sun generates energyHow the sun generates energyProcess where two hydrogen nuclei fuse Process where two hydrogen nuclei fuse
to form heliumto form heliumThe beginning of a stars life The beginning of a stars life
Click to view video clip!
The Life Cycle of StarsThe Life Cycle of Stars
Stars begin life as a ball of gas and dustStars begin life as a ball of gas and dustTemperatures reach 10,000,000 CTemperatures reach 10,000,000 CNuclear Fusion begins Nuclear Fusion begins This stage known as a ProtostarThis stage known as a Protostar
Main SequenceMain Sequence
Main Sequence is the second and longest Main Sequence is the second and longest stage of a star’s lifestage of a star’s lifeHydrogen continues to fuse into heliumHydrogen continues to fuse into heliumSize of star changes very little during this Size of star changes very little during this
stagestage
Giants and SupergiantsGiants and Supergiants
Giants and Supergiants result when a star Giants and Supergiants result when a star uses all the hydrogen in its coreuses all the hydrogen in its core
Star grows very large and coolsStar 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 StarsWhy We Study Stars
The structure and composition of the The structure and composition of the universe can be learned by studying stars universe can be learned by studying stars and galaxies and their evolution.and galaxies and their evolution.
Understanding the properties of stars Understanding the properties of stars provides us with an understanding of our provides us with an understanding of our sun, which is a star!sun, which is a star!
The properties of the sun affect Earth The properties of the sun affect Earth directly, so it is important to know them.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)
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) A white dwarf
b) A pulsar
c) A red giant
d) 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 CitedWorks Cited
My vacation
• Look at this sunset!