stars and galaxies
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Stars and Galaxies. Chapter 25. Section 1 The Study of Stars. Objectives: Describe the electromagnetic spectrum Explain how reflecting and refracting telescopes work Compare and Contrast optical telescopes and spectroscopes - PowerPoint PPT PresentationTRANSCRIPT
Section 1 The Study of Stars
Objectives:Describe the electromagnetic spectrumExplain how reflecting and refracting telescopes workCompare and Contrast optical telescopes and spectroscopesInfer the relationship between the frequency of electromagnetic waves and their wavelength
Skills Warm-up
Star WordsWrite as many words as you can to describe stars from just observing them.Write something you know about stars but can’t tell by just looking at them.Compare your words with your classmates.
StarsStars are swirling, glowing balls of ______
There are > 200,000,000,000 billion
The _______ is very important to earth, but it is just an average ____
Many other stars are much _______ and ________
How are stars studied?
Electromagnetic Spectrum
All stars produce energy in the form of
___________ __________:________ ________
________ ________
________
________
Each type of energy has a
characteristic ________ and _________
____________ ________ - all types of electromagnetic wave energy, from very low frequency to very high frequency
Optical Telescope
Microscopes use _______ to collect visible light from ______ _______ and produce _________ that are much __________
________ __________ work the same way, using ________ or _________ to collect visible light
The only difference is that the light comes from a ______ ______ and _______ _______
It then makes the distant object look ________ and _________
Optical Telescopes
________ telescope – uses ______ to collect and focus visible light
_______ telescope – uses ______ to collect and focus visible light
Optical Telescopes
The ______ a mirror or lens, the ______ the image it can make
But, if they get too big, they _____ from their own _______
The telescope with the largest single mirror (5 m in diameter) is in the _____ _________ in California
SpectroscopesA star’s ______ _______ has a characteristic spectrum of light of different wavelengths because each ________ __________ in the star blocks particular wavelengths of light
By looking at a star’s ________, scientists can figure out what its _________ ________ is
A _________ contains a _______ to separate the light and a small optical telescope to see the spectrum
Stars contain ~ 75% ________ and 22% _______
Radio TelescopesCollect ______ _______ from space
________ _______collects waves that are reflected to the antenna and then ___________
Good for studying -______ and ________ and have helped us learn about our own ________
ActivityWork in pairs
Complete Skills Worksheet 25.1
Please hand in completed worksheet by tomorrow – if necessary, finish for homework
Section 2 Characteristics of Stars
Objectives:Relate the temperature of a star to its colorExplain how measurements of parallax are used to measure a star’s distance from earthContrast absolute magnitude and apparent magnitudeInterpret data from an H-R diagram
Skills Warm-up
Stars in the SkyMake a list of the sun’s characteristics.Which of these do you think are shared by all stars?Which characteristics of the sun do you think are different from other stars?
Distance of StarsHold your finger in front of your face.
Look at it with your left eye closed.
Then look at it with your right eye closed.
Does your finger seem to move or change position relative to the background?
Distance of Stars
Now find an object across the classroom from you.
Look at it with your left eye closed.
Then look at it with your right eye closed.
Does this object move position as much as your finger did?
Distance of Stars
___________ – apparent change in the position of an _______ due to change in position of the __________
Scientists use parallax to determine the _________ of a star from __________
As earth moves around the sun, _______ stars appear to ______ position relative to more __________ stars
The ________ a star is to earth, the __________ its apparent change of position
Measurements of change in position can be ___________ into measurements of distance
Distance of Stars
Distances of stars are so ________ - you can’t use any normal _______ _____ ____________Scientists use ______________
The distance that light, travelling at a speed of 310,000 km per second, will cover in 1 year Equal to 9.5 trillion kmProxima Centauri – ________ star to earth at 4.2 light-yearsMost stars are hundreds of light-years away
Magnitude of Stars
______________ – brightness of starsThe ___________ the star, the _________ its number of magnitude
A star with a magnitude of -2 is brighter than one with a magnitude of 2
___________ magnitude – a star’s brightness from earth
Doesn’t really tell you how much light is given off
___________ magnitude – actual brightness of a star from a standard distance
Hertzsprung-Russell Diagram
Two scientists graphed a large number of stars based on their ________ __________ and _____________
4 Types of Stars:______ __________ – stars grouped in a diagonal band from hot/bright to cool/dim
____________ – very bright stars that range from cool to medium/hot
_______ _______ – medium bright but cool
_______ _______ – low magnitude but relatively hot
ActivityWork in pairs
Complete Skills Worksheet 25.2
Please hand in completed worksheet by tomorrow – if necessary, finish for homework
Section 3 Life Cycles of Stars
Objectives:Explain how stars come into beingDescribe the stages of a star’s lifecycleContrast the different ways in which high-mass and low-mass stars end their life cyclesPredict what will happen for the rest of the sun’s lifecycle
Skills Warm-up
The Life of StarsList and describe each stage of the human life cycle.How do you think the human life cycle is different from that of a star?
Star LifecycleHuman life cycle lasts about _____ ________
Born
Infant
Toddler
Child
Teenager
Adult
Senior citizen
Star LifecycleStars are also _______, then _______ and eventually ______
Star life cycle lasts _______ __ _______
Stars in the sky are at _________ stages
Our sun is about ____ way through its ____________ year life cycle
Birth of a Star______ – a cloud of _____ and ______ where stars are born
Made of mostly _________ with _______ and _______
Gravity causes the spread out particles of matter to ___________
Matter starts to heat up and becomes a ____________
Protostars don’t shine, but give off _________ energy
Eventually they become hot enough for ________ to occur and a star is born
Low Mass-Stars – mass is less than ______ that of
the ______Low-Mass Star Lifecycle:
Begins as a ____________star but gradually the supply of _________ is changed by fusion into _________
_________ _________– core of star starts to collapse
becomes hotter and denser
helium is converted to __________
short part of life cycle
________ __________– Star cools and collapses inward to be a _________ dwarf
Eventually no light is given off and is a __________ dwarf
High Mass-Stars – mass is more than ____ that of
the _____High-Mass Star Lifecycle:
Uses up __________ at a much faster rate
____________ __________– ___________ runs out
Core collapses
Outer layers expand greatly
____________ _________– Pressure builds up and causes a massive ____________
When only tiny core of neutrons remains it becomes -
_________ _____– dense core of neutrons
________ ________– so dense and gravity so strong nothing can escape it
ActivityWork in pairs
Complete Skills Worksheet 25.3
Please hand in completed worksheet by tomorrow – if necessary, finish for homework
Section 4 Galaxies and Star Groups
Objectives:Describe the 4 types of galaxiesExplain what a constellation is and how it differs from a galaxy or star clusterExplain how scientists know the universe is expandingPredict how the constellations will look in the distant future
Skills Warm-up
Lions and Tigers and …..When you look at the sky on a clear night, what shapes do the stars make?Draw what they look like to you.
Galaxies______ – collection of _____, nebulae, _______, dust, and _______ that move through space as a unit – held together by gravity
There are at least __ ______ galaxies in the universe – ours is the ______ ____
Types of Galaxies
_______ – flat disk with a bulge in the middle
Have long spiral arms that swing out and rotate like a _________
Contain large amounts of ____ and ______
Example – _____ _____
Types of Galaxies
_____ ______– similar to spiral but arms are attached to a straight bar shape
Bar is much _______ and ________ than the arms
______ common than spiral
Example – _______ _______
Types of Galaxies
__________ – football shaped
Rotate differently than spirals – more ________
Contain ______ gas and dust
Example – _______
Types of Galaxies
________ – don’t have regular shapes
_____ greatly in size
____ common type
Example – _____ ________ ______
Constellations_____ ________shaped like people, animals, or objects
There are ______ official constellations
The stars in constellations may look like they are close together from earth, but they are not
Constellations are important because
_______________________
_______________________
_______________________
Expansion of the Universe
______ ______ _______:15 – 20 million years ago all matter in the universe was packed into one ______ ________
The fireball exploded, spreading ______ and ________ out in all directions
As matter cooled, the force of gravity pulled together the particles of matter to form _____ ____ _________
The universe was born!!!
Expansion of the Universe
What’s the proof???
The ___________ EffectThe light waves from an object _____ ______from earth are spaced more ______ apart than if it were _______ _______
The waves appear to have a longer _________ than they really have and shift to the _____ ______ of the visible light spectrum
All other galaxies have a red shift in their spectrums which means they are moving _____ from earth
http://video.search.yahoo.com/video/play?ei=UTF-8&fr=yfp-t-701&fr2=tab-img&p=doppler+effect+audio&vid=1078797468712&dt=30145135&l=78&turl=http%3A%2F%2Fts1.mm.bing.net%2Fvideos%2Fthumbnail.aspx%3Fq%3D1078797468712%26id%3D9e034c60fc3e4bfc86990a9e32a16274%26bid%3DQwi6yfYlRKH4KQ%26bn%3DThumb%26url%3Dhttp%253a%252f%252fvideos.howstuffworks.com%252fdiscovery%252f27963-assignment-discovery-doppler-effect-video.htm&rurl=http%3A%2F%2Fvideos.howstuffworks.com%2Fdiscovery%2F27963-assignment-discovery-doppler-effect-video.htm&tit=Assignment+Discovery%3A+Doppler+Effect&sigr=12th87akt&newfp=1
Doppler Effect Video
Beyond the Solar System
Do you think that reaching other stars may some day be possible??????
Problems:_______ – a spaceship travelling at the speed of light would take over 8 years to make a round trip to the nearest star
________ – we don’t have a spaceship that can travel anywhere near the speed of light
_____ _______– it would be difficult for people to travel, so scientists are looking to send data collecting devices instead
ActivityWork in pairs
Read Unit 9: The Milky Way Galaxy and Beyond
Complete attached worksheet “Quick Check”
Please hand in by tomorrow – if necessary, finish for homework
Debate
I will split the class into 2 teams and assign which side of an issue your team will be arguing on.
Take ½ of the class period with your team to come up with arguments to support your part of the issue.
Pick 4 representatives from each team to debate against the opposing team.
Issue:Is space exploration worth the cost????
How valuable is more knowledge about the universe?
What could be done with the money that is currently being used for space exploration?