1 stars, galaxies & universe chapter 3. 2 tools of astronomy constellations are groups of stars...
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Stars, Galaxies & Stars, Galaxies & UniverseUniverse
Chapter 3Chapter 3
22
Tools of AstronomyTools of Astronomy
• Constellations are groups of stars that form a pattern.
• The electromagnetic spectrum is made of radio waves, infrared radiation, visible light, ultraviolet radiation, x-rays, and gamma rays.
33
Refracting TelescopeRefracting Telescope
• Refracting telescope collects light using lenses.
• The lenses bend the light to the focal point.
44
Reflecting TelescopeReflecting Telescope
• Reflecting telescope uses a mirror to collect the light.
• A concave mirror bends the light inward to a focal point.
55
Radio TelescopeRadio Telescope
• Radio telescopes collects radio waves.
• The collector is a concave dish.
66
ObservatoryObservatory
• The building that houses a telescope is called an observatory.
77
Other Tools of AstronomyOther Tools of Astronomy
• Telescopes have been put into space on satellites & space stations.
• Spectrographs gather information about stars such as a star’s composition & temperature.
88
Which type of telescope focuses Which type of telescope focuses light using a mirror?light using a mirror?
Ref
lect
ing T
eles
cope
Ref
ract
ing
Teles
cope
Rad
io T
eles
cope
Infra
red T
eles
cope
0 000
A. Reflecting Telescope
B. Refracting Telescope
C. Radio Telescope
D. Infrared Telescope
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99
Which type of telescope focuses Which type of telescope focuses light through transparent lenses?light through transparent lenses?
Ref
lect
ing T
eles
cope
Ref
ract
ing
Teles
cope
Rad
io T
eles
cope
Infra
red T
eles
cope
0 000
A. Reflecting Telescope
B. Refracting Telescope
C. Radio Telescope
D. Infrared Telescope
:10
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1010
One of the greatest advancements in One of the greatest advancements in astronomy was the telescope. Which is astronomy was the telescope. Which is
the correct order of advancements?the correct order of advancements?
0 000
A. Radio- refracting-reflecting
B. Reflecting – refracting –radio
C. Refracting-reflecting-radio
D. Radio- reflecting-refracting
:10
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1111
Which of the following is an advantage of Which of the following is an advantage of a space-based, satellite telescope like a space-based, satellite telescope like
Hubble?Hubble?
0 000
A. Satellite telescopes are much closer to the stars.
B. Satellite telescopes are able to see through solid objects.
C. Satellite telescopes can detect wavelengths that are blocked by the atmosphere.
D. Satellite telescopes have the ability to see the future.
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Characteristics of StarsCharacteristics of Stars
• A galaxy contains hundreds of billions of stars.
• The universe contains billions of galaxies.
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Distances to StarsDistances to Stars
• A light year is the distance light travels in year.
• Astronomers often use parallax to measure distances to nearby stars.
• Parallax is the apparent change in position of an object when you look at it from different places.
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A light year is a measurement of…A light year is a measurement of…
Dis
tanc
e
Tim
e
Spee
d
Acc
eler
atio
n
0% 0%0%0%
a) Distance
b) Time
c) Speed
d) Acceleration
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Why do astronomers measure interstellar Why do astronomers measure interstellar distances in light years instead of distances in light years instead of
kilometers or miles?kilometers or miles?
Lig
ht yea
rs a
re a
mea
...
Mile
s an
d kilo
met
ers
a..
Mile
s an
d kilo
met
ers
a..
I don’t
have
a cl
ue . .
....
0 000
A. Light years are a measure of time.
B. Miles and kilometers are too small of a unit.
C. Miles and kilometers are too large of a unit.
D. I don’t have a clue . . . help me!
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One light year equals about how One light year equals about how many kilometers?many kilometers?
365
km
9.5
trill
ion k
m
365
day
s
9.5
day
s
0% 0%0%0%
a) 365 km
b) 9.5 trillion km
c) 365 days
d) 9.5 days
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Classifying StarsClassifying Stars
• Stars are classified by size, temperature, and brightness.
• Temperature of a star is indicated by color, hot stars are blue & cooler stars are red.
• Apparent brightness is the brightness of a star as observed from earth.
• Absolute magnitude is the brightness of a star observed at the distance of 10 parsecs.
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Hertzsprung-Russell DiagramHertzsprung-Russell Diagram
• H-R diagram is a graph of the Milky Way galaxy.
• Surface temperature is graphed on the x-axis.
• Absolute magnitude is graphed on the y-axis.
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Types of StarsTypes of Stars
• Blue super giants have a high brightness and high temperature.
• Red giants & super giants have a high brightness and low temperature.
• White dwarfs have a low brightness and high temperature.
• 90% of all stars appear on the Main Sequence going from the upper right to the lower left corner.
2020
Why do stars appear to be different Why do stars appear to be different colors?colors?
chem
ical
com
positio
n
dis
tanc
e s
ize
tem
perat
ure
0% 0%0%0%
a) chemical composition
b) distance
c) size
d) temperature
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2121
Which color star would be the Which color star would be the hottest?hottest?
blu
e re
d
white
yel
low
0% 0%0%0%
a) blue
b) red
c) white
d) yellow
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2222
Which star would be the brightest?Which star would be the brightest?
Mai
n seq
uence
Red
gia
nts
Red
supe
r gia
nts
Whi
te d
war
f
0% 0%0%0%
a) Main sequence
b) Red giants
c) Red super giants
d) White dwarf
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2323
How would you classify our star, How would you classify our star, the sun, on the H-R diagram?the sun, on the H-R diagram?
Mai
n seq
uence
Red
gia
nt
Whi
te d
war
f
Red
supe
rgia
nt
0% 0%0%0%
a) Main sequence
b) Red giant
c) White dwarf
d) Red supergiant
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Birth of a StarBirth of a Star
• A star begins as a cloud of gas and dust called a nebula.
• Gravity pulls the gas and dust together into a protostar.
• A star is born when the contracting gas and dust becomes so hot that nuclear fusion begins.
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Length of Life of a StarLength of Life of a Star
• More massive stars live short lives of millions of years.
• Less massive stars live long lives of billions of years.
• The sun will live for 9-10 billion years.
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During the Life Cycle of a StarDuring the Life Cycle of a Star
• Stars fuse hydrogen into helium during most of their lives.
• After all the hydrogen has been fused into helium, the star fuses helium into carbon, carbon into oxygen and then oxygen into iron.
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Death of a StarDeath of a Star
• Stars use up their hydrogen and expand their atmosphere.
• Stars that are less than 1.4 solar masses will shrink to a white dwarf.
• Stars between 1.4 -3.0 solar masses will produce a supernova and leave a neutron star.
• Stars more than 3.0 solar masses will produce a supernova and collapse into a black hole.
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What is the first stage of the birth of What is the first stage of the birth of a star?a star?
Pro
tost
ar
Neb
ula
Gia
nt
dw
arf
0% 0%0%0%
a) Protostar
b) Nebula
c) Giant
d) dwarf
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What is the next likely stage of a What is the next likely stage of a protostar?protostar?
Super
Gia
nts
Nova
Mai
n Seq
uence
Neu
tron S
tar
0 000
A. Super Giants
B. Nova
C. Main Sequence
D. Neutron Star
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What happens to the most massive What happens to the most massive stars as they near their death?stars as they near their death?
super
nova
to a
bla
ck...
super
nova
to a
neu
tr..
bec
omes
a w
hite d
war
f
noth
ing h
appen
s
0% 0%0%0%
a) super nova to a black hole
b) super nova to a neutron star
c) becomes a white dwarf
d) nothing happens
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What is the next likely stage of our What is the next likely stage of our sun?sun?
Whi
te d
war
f
Bla
ck d
war
f
Red
gia
nt
Super
nova
0% 0%0%0%
a) White dwarf
b) Black dwarf
c) Red giant
d) Super nova
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Star SystemsStar Systems
• Most stars are members of groups of two or more stars called star systems.
• Star systems with two stars are called double stars or binary stars.
• Binary eclipsing stars are stars where one star blocks the light from another.
3333
GalaxiesGalaxies
• Galaxies are a group of billions of stars.
• Type of galaxies are 1. Elliptical
2. Spiral
3. Irregular
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Elliptical GalaxyElliptical Galaxy
• Old galaxy.• Contains red star that
are old.• No gas or dust.
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Spiral GalaxySpiral Galaxy
• Middle aged galaxy.• Contains blue stars.• Has some dust and
gas.• Our Milky Way is a
spiral galaxy.
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Irregular GalaxyIrregular Galaxy
• Unorganized collection of stars.
• Made of very young stars.
• Has a great deal of gas and dust.
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History of the UniverseHistory of the Universe
• Edwin Hubble discovered that the farther away a galaxy is from us, the faster it is moving away from us.
• Stars moving away from us shows a red shift.
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Big Bang TheoryBig Bang Theory
• Big Bang Theory suggest that billions of years ago, the universe was small, hot and dense and then the universe exploded.
• The universe formed in this enormous explosion about 10 to 15 billion years ago.
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Formation of the Solar SystemFormation of the Solar System
• The solar system formed 5 billion years ago.
• The solar system formed from a giant cloud of gas and dust, or nebula.
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Future of the UniverseFuture of the Universe
• The universe may continue to expand.
• Gravity may pull the universe back together.
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By what are galaxies classified?By what are galaxies classified?
Colo
r
Tem
perat
ure S
ize
Shap
e
0% 0%0%0%
a) Color
b) Temperature
c) Size
d) Shape
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What type of galaxy is illustrated in What type of galaxy is illustrated in the following picture?the following picture?
Irre
gular
Spira
l
Elli
ptical
I hav
e no id
ea..
I nee
d...
0% 0%0%0%
a) Irregular
b) Spiral
c) Elliptical
d) I have no idea.. I need help!
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4343
What type of galaxies contain older What type of galaxies contain older stars?stars?
Elli
ptical
Irre
gular
Bar
red s
hape
spira
l
0% 0%0%0%
a) Elliptical
b) Irregular
c) Barred shape
d) spiral
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Review QuestionsReview Questions
• What are the three types of galaxies?
• elliptical, spiral & irregular
• Distances between stars are measured in units called _______.
• light years
• Stars begin as a cloud of gas & dust known as a __________.
• nebula
4545
Review QuestionsReview Questions
• What does the length of life of a star depends on?
• mass of the star• What is the name of our galaxy?• Milky Way• What type of galaxy is the Milky Way?• spiral• What is the name of the theory of the creation of
the universe?• Big Bang
4646
Review QuestionsReview Questions
• What type of tools are used to study the universe?
• telescope
• Which type of telescope uses mirrors?
• reflecting
• Which type of telescope uses lenses?
• refracting
4747
Review QuestionsReview Questions
• What indicates how hot a star is?
• color of the star
• During nuclear fusion, what does hydrogen fuse into?
• helium
• What is graphed on the H-R diagram?
• brightness & temperature
4848
Review QuestionsReview Questions
• What is the brightness of a star as seen from earth?
• apparent brightness
• What is the brightness of a star that is seen at a standard distance of ten parsecs?
• absolute magnitude
4949
Review QuestionsReview Questions
• What process is used to measure the distance of nearby stars?
• parallax
• What type of telescope collect electromagnetic waves other than light?
• radio telescope
• How long ago did the Big Bang occur?
• 10-15 billion years ago
5050
Review QuestionsReview Questions
• What are patterns of stars in the sky called?• Constellations• What is the building called that has a telescope?• Observatory• Which type of galaxy has red stars and no gas
or dust?• elliptical
5151
Review QuestionsReview Questions
• Which type of galaxy has blue stars and some gas & dust?
• spiral galaxy
• Galaxies are classified by their _______.
• shape
• Who proposed that the universe is expanding?
• Hubble
5252
Review QuestionsReview Questions
• What evidence do we have that the universe is expanding?
• red shift
• What happens to a small star at its death?
• white dwarf
• What happens to a very large star at its death?
• Supernova to a black hole
5353
Practice Extended Answer Practice Extended Answer QuestionsQuestions
• Describe the life cycle of a star.• What are the three types of telescopes and how
are they different?• Explain the H-R diagram.• How does the mass of a star affect the length of
life of a star?• How do the different types of galaxies compare?• Explain the Big Bang Theory.
5454
One of the greatest advancements in astronomy One of the greatest advancements in astronomy was the telescope. Which is the correct order of was the telescope. Which is the correct order of
advancements?advancements?
0 000
A. Radio- refracting-reflecting
B. Reflecting – refracting –radio
C. Refracting-reflecting-radio
D. Radio- reflecting-refracting
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21 22 23 24
5555
What is the next likely stage of a What is the next likely stage of a protostar?protostar?
Super
Gia
nt
Nova
Mai
n Seq
uence
Neu
tron S
tar
0% 0%0%0%
a) Super Giant
b) Nova
c) Main Sequence
d) Neutron Star
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21 22 23 24
5656
Why do astronomers measure interstellar Why do astronomers measure interstellar distances in light years instead of kilometers or distances in light years instead of kilometers or
miles?miles?
Lig
ht yea
rs a
re a
mea
...
Mile
s an
d kilo
met
ers
a..
Mile
s an
d kilo
met
ers
a..
I don’t
have
a cl
ue . .
....
0 000
A. Light years are a measure of time.
B. Miles and kilometers are too small of a unit.
C. Miles and kilometers are too large of a unit.
D. I don’t have a clue . . . help me!
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24
5757
Which of the following correctly shows the age Which of the following correctly shows the age progression of an average star?progression of an average star?
0 000
A. Main sequence→White Dwarf→Red Giant →Nebula
B. Red Giant →White Dwarf →Main Sequence →Nebula
C. Nebula →Main Sequence →Red Giant →White Dwarf
D. White Dwarf →Red Giant →Main Sequence →Nebula
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5858
What type of galaxy is shown in the What type of galaxy is shown in the picture?picture?
0
0
0
0
A. Irregular
B. Spiral
C. Elliptical
D. I have no idea … I need help!!!
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