Astronomy Unit 2

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Astronomy Unit 2

• Name______________

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Chapter 23 Touring Our Solar System
Section 23.1 The Solar System
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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• __________________________________
• The sun and the bodies that revolve around it
• Some solar systems have two suns.
• ________________
• Any one of the eight major bodies that orbit the
  sun
• Exist in other solar systems

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Development of the solar system
• _____________ _________________
• Theory that the sun and the planets condensed out
  of a spinning cloud of gas and dust
• The entire solar system formed at approximately
  the same time.
• Developed by French mathematician Marquis Pierre
  Simon de Laplace

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Nebular Theory

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Formation of the sun
• The big bang spread matter throughout the
  expanding universe, some of which gathered into
  clouds of gas and dust
• ________________
• Cloud of gas and dust that developed into the
  solar system
• ____________ ______________from a nearby
  supernova or some other force causes the nebula
  to contract, causing the beginning of the sun to
  form in the center of the solar nebula
• ______________ from collisions and ___________
  from the force of gravity caused the sun to
  become hotter and denser until fusion began and
  the sun actually could generate energy.

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• About 99 of the matter in the solar nebula
  became part of the sun.

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Solar nebula evolution

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Formation of the planets
• ____________________
• Small bodies of matter that formed in the outer
  regions of the solar nebula while the sun was
  forming in its center
• Some joined together through collisions and
  through gravitational forces to form larger
  bodies.
• ___________________
• Large bodies of matter that formed from the
  coalescence (coming together) of planetesimals in
  the solar nebula
• Protoplanets gravities acted like giant
  gravitational magnets to pull in more
  planetesimals from the solar nebula

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Condensed into existing planets and __________
  (bodies smaller than planets that orbit their
  respective planets)
• Planets and moons are smaller and denser than
  protoplanets

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Terms to know

• ___________ a planet spinning on its axis.
  Causes __________/___________.
• ____________ going around the sun. One trip
  around for that planet is called a ________.

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Distance between the sun and the protoplanets
  affected element compositions of each planet
• Inner planets (_________ ___________)
• ______________, ________________
• ________________ and __________.
• Contained large amounts of the heavier elements,
  such as iron, making them more dense
• Could not accumulate lighter gases because of
  high temperatures close to the sun
• Outer planets (__________ _____________)
• ________________,________________,
• __________________, and ______________
• Formed in the cold regions of the solar nebula
• ___________ dense than the terrestial planets

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Consist of helium, hydrogen, and frozen gases
  such as water, methane, and ammonia
• Thick layers of ice surrounding small cores of
  heavier elements
• Developed into much bigger planets
• Outer planets could keep a lot of their original
  gases, helping some to be gas giants (such as
  Jupiter) and to remain big planets
• Primary differences between Jovian planets and
  terrestial planets
• _____________
• _____________ _______________
• ____________ of _______________

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Mercury

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Mercury

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Venus

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Earth

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Mars

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Jupiter

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Saturn

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Uranus

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Chapter 23 Touring Our Solar System-- Section
23.1 The Solar System --

• Neptune

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Chapter 24 Studying the Sun
Section 24.1 The Study of Light
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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• The Scientific Method
• __________________ (observing problems)
• ______________ (an educated guess of what to
  expect if something
• ________________ (testing the hypothesis for
  validity)
• __________ _____________(analyzing data from the
  experimentation process)
• ______________ (what was discovered from the
  experiment)
• _________________ (hypothesis repeatedly
  supported by experiments and observations)
• Difference between theories and laws
• Scientific theory
• Explains a big idea
• Something that cant normally be seen (too small,
  large)
• States why something occurs in nature
• Can be disproven

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• ______________ ____________
• Rule that correctly describes a natural
  phenomenon
• States what occurs for something in nature
• Generally has never been disproven
• Example Law of gravity, theory of gravitation
• Development of the big bang theory
• Light and the Doppler effect
• ______________
• Small packets of light energy
• Behave like particles instead of waves
• Light
• Produces a rainbow of colors when passed through
  a prism

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• ________________
• Band of the various colors of light
• Different kind of spectra exist

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --
Production of Continuous Spectrum
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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• Travels in waves
• ___________________
• Distance from one crest of a wave to the next
  crest of a wave
• Generally measured in nanometers (nm) or
  angstroms (A) when talking about visible light
• ___________________
• How many wavelengths pass a certain point per
  second
• Generally measured in hertz (Hz), which means so
  many waves per second
• ____________________
• Amount of energy carried by a wave
• Generally measured by the height of a wave

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --
Electromagnetic Wave
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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• Production of spectra
• _____________________
• Study of the properties of light that depend on
  wavelength
• Types of spectra (generations of colors by light)
• ________________ spectrum
• An uninterrupted band of light emitted by an
  incandescent solid, liquid, or gas under high
  pressure
• Example visible light generated by a light bulb
• _________________ spectrum
• Continuous spectrum produced when white light is
  passed through a cool gas under low pressure

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• The gas absorbs certain wavelengths of light,
  resulting in the appearance of dark lines
• Most common spectra of stars
• Also known as ___________-_______ __________
• _______________________ ____________________
• A series of bright lines of particular
  wavelengths produced by a hot gas under low
  pressure
• Appear in exact same locations as dark lines do
  in the absorption spectrum
• Also known as bright line spectra
• Each spectrum is like a fingerprint for an
  _____________ (substances that cannot be broken
  down into simpler forms by ordinary chemical
  means) so scientists can identify a stars
  composition

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --
Formation of a Continuous Spectrum
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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --
Formation of a Bright-Line Spectrum
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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• _______________ ____________________
• Apparent shift in the wavelength of energy, such
  as a sound wave or a light wave, emitted by a
  source moving away from or toward an observer
• Properties of the Doppler effect

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• Object moving away light waves
  appear_____________
• Wavelengths appear longer resulting in shift
  toward the _____ end of the spectrum
• Called a _____________ ___________
• Object moving toward observer
• Light waves appear ___________ resulting in a
  shift toward the ____________ end of the spectrum
• Example with sound _____________ whistle

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• The Red Shift
• Discovered using a ____________________
• Instrument that splits white light into a band of
  colors
• Used to determine what elements are present in
  stars based on bright-line spectra produced as
  well as the percentages of elements in those
  stars
• Tested on _______________ (large systems of stars
  and planets)
• The spectra of most galaxies tested were shifted
  toward the red end of the spectrum.
• The red shift indicates that almost all of the
  galaxies in the universe are moving _________
  from Earth.

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• Galaxies furthest away had the greatest amount of
  red shift, indicating the universe is expanding.

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --
Formation of a Continuous Spectrum
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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --

• Telescopes
• Visible light telescopes
• ___________________ ________________
• Telescope that uses lenses to focus visible light
  
• Some of the first telescopes
• _____________ _______________
• Telescopes that uses mirrors to focus visible
  light
• Majority of telescopes today
• Radio telescopes using ____________________
  (linking separate telescopes together to act as
  one telescope)
• Telescopes in space (infrared, ultraviolet,
  x-ray, and gamma ray) to detect radiation blocked
  by Earths atmosphere
• ___________________________________________
• _________________________and Compton Gamma-Ray
  Observatories

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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --
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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --
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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --
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Chapter 24 Studying the Sun-- Section 24.1
The Study of Light --
Radio Telescopes
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Chapter 25 Beyond Our Solar System
Section 25.1 Properties of Stars
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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• ______________
• Body of gases that gives off a tremendous amount
  of energy in the form of light and heat
• Statistics on stars
• 1 in __________ stars are single stars.
• 1 of ____________ stars are double stars.
• ___________________________
• Pattern of stars
• Identification of constellations and stars
• Pictures that they form in the sky based on
  mythology
• Labeling of stars based on the Greek alphabet and
  brightness
• Brightest star ____(alpha)
• Second-brightest star ____ (beta)

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --
Constellation of Orion
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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --
Constellation of Orion
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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• Composition and temperature
• _______________________
• Device that separates light into different colors
  or wavelengths
• Production of a spectrum
• _______________ spectrum
• ________________ spectrum (bright-line)
• _______________ spectrum (dark-line)
• Shown by the absorption (dark-line) spectra of
  stars.
• Composition
• ___________________ is the most common element in
  most stars.
• __________________ is the second most common
  element in stars.

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• Iron, sodium, and calcium make up the remaining
  elements in stars.
• Temperature
• Surface temperature of a star is indicated by its
  ______________.
• Range of star colors and temperatures
• Our sun 5,500?C
• Motion of stars
• Two kinds of motion
• ________________ motion
• Motion seen by cameras and the visible eye
• Circular motion around Earth
• Movement to the west over time

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• Movement to the west over time
• Certain stars only available for viewing during
  certain seasons because of Earths revolution
  around the sun.
• ______________________ __________________(describ
  ing any star that is always visible in the night
  sky and, from the Northern Hemisphere, can be
  seen circling Polaris)

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• Circumpolar Stars

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• _______________ ___________________
• Stars rotate on an axis.
• Stars may revolve around another star.
• Stars may move away from or toward Earth.
• Demonstrated by examining wavelengths and
  examining the Doppler shifts in determining red
  shifts (moving further away by longer wavelengths
  being shown) or blue shifts (moving closer by
  shorter wavelengths being shown)
• Distance of stars
• _________________ _________________
• Distance that light travels in one year
• About 9.5 trillion kilometers

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• Methods to determine distances between the stars
• ______________________
• Method of determining the distance from Earth to
  a star based on the shift in the apparent
  position of the star when viewed from different
  angles

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• Occurs as a result of the revolution of Earth
  about the sun
• The closer a nearby star, the greater its shift
  in position and the greater its apparent motion
• Comparison of true brightness of a star to its
  apparent brightness
• Special stars serving as distance indicators
• Magnitudes of stars
• Visibility of a star depends on two factors
• ? Brightness
• ? Distance from Earth
• Types of magnitude
• __________________ ________________
• Brightness of a star as it appears from Earth
• Brightest stars negative numbers

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• ________________ stars positive, high numbers
• Faintest star can be seen by the naked eye has an
  apparent magnitude of 6, known as a sixth
  magnitude star

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• ___________________ magnitude
• Brightness of a star as it would appear if
  located 32.6 light years from Earth
• Also known as the true brightness of a star
• Most stars have absolute magnitudes between - 5
  and 15
• Classifications of stars
• ___________________________
• Graph showing the relationship of the surface
  temperature and absolute magnitude of a star
• Hertz_____________-__________________diagram
• The brightness of most stars increases as their
  surface temperature increases.

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• H - R diagram

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• H - R diagram

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• H - R diagram

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• Star classifications
• __________-______________ ________________
• Star with characteristics that place it within a
  band running through the middle of the H-R
  diagram
• Extends from cool, dim, red stars at the lower
  right to hot, blue, bright stars at the upper
  left

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• ___________
• Very large, cool, bright stars
• Found in the upper-right corner of the H-R
  diagram

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• _____________________
• Stars with similar properties to giants but much
  greater in size
• Found further to the upper-right corner of the
  H-R diagram

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Chapter 25 Beyond Our Solar System-- Section
25.1 Properties of Stars --

• ___________________ _______________
• Small, hot, dim stars
• Found in the lower-left corner of the H-R diagram
• Dim because of small size
• Typical white dwarf size of Earth

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Chapter 25 Beyond Our Solar System
Section 25.2 Stellar Evolution
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• Evolution of stars deals with different stages
• Stages of development
• ? ______________
• Dark cloud of gas and dust in space
• 70 H, 28 He, 2 heavier elements
• Process to next stage
• ? Particles start off with weak gravitational
  attraction for each other.
• ? External force of something like an explosion
  of a nearby star causes particles
  to_______________and the nebula to compress.
• ? ____________________ of particles increases,
  causing more gravitation between particles
  because of increases in density, causing
  particles to come together into a sphere in the
  center.

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• ? The nebula spins more rapidly because of
  gravitational forces and forms ________________.
• NOTE Nebula can produce two or more stars.

Rosetta Nebula
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• Lagoon Nebula

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• Huge pockets of contracting interstellar material
  are thought to condense into smaller globules,
  called Bok Globules (the bright parts), which
  form _______________________.

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• Protostar
• _______________ of a shrinking, spinning nebula
• Temperature increases in _________________of the
  protostar for two reasons
• ? Collision of particles and conversion into
  _________
• ? Extreme pressure increases in core of
  protostar
• Process to next stage
• ? Contracting and heating up of the nebula goes
  on for ______________________ _________________ye
  ars.
• ? Temperature rises above 10,000,000?C to start
  nuclear fusion (small atomic nuclei combining to
  form larger atomic nuclei and releasing energy)
  at which point it is considered a star.

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Protostar formation
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Protostar formation
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Protostar
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• ? Main sequence star
• Process to next stage
• ? Energy is generated in the core of the star
  while __________________ atoms fuse together to
  ________________ _____________ atoms.
• ? The star doesnt expand because force of
  ___________ and the force of the ____________
  generated by fusion _____________e each other.
• ? Will stay as a main sequence star as long as
  there is hydrogen to fuse into helium

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Main sequence stars
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Main sequence stars in H-R diagram
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• ? Giant or supergiant star
• Process to ______________ ______________
• ? Occurs when most all hydrogen is ____________
  and helium starts _________________ with other
  helium
• ? The star starts _________________ under its
  own ________________, causing higher
  temperatures, and helium fuses into carbon while
  the remaining hydrogen fuses into helium.
• ? The combined fusion releases a lot of energy
  causing the outer shell to ________________
  rapidly and cool as it moves outward.

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• White dwarf
• Small, hot, dim star
• Remaining, contracted core of the planetary
  nebula
• Shines for billions of years before completely
  cooling
• Result of low-mass, main-sequence stars

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
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Life cycle of a star schematic

• Nebula
• Gravity pulls together to make a
• Protostar
• Gravity/weight/density causes fusion of H to make
  a
• _______ _____________star (where sun is now)
• Uses H as fuel. When H is used up He core
  contracts but no fusion, outer layers expand b/c
  of heat from the core to make a
• _________ __________
• Core collapses until He fuses to C as a white
  dwarf to make a
• Planetary nebula and __________ ___________

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• ___________ dwarf
• White dwarf that no longer emits energy
• Also known as a dead star
• Probably do not exist yet since the universe is
  not old enough to have produced them
• Other phenomenon
• _____________
• White dwarf that explodes as it cools,
  temporarily becoming thousands of times brighter
• Releases energy, gas, and dust in space
• White dwarfs may become a nova several times
• Most likely to occur around a main-sequence star
  or giant star

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Beginning of a nova formation
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Evolution of a nova
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Nova
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• __________________
• Star that blows apart with a tremendous
  ___________
• Occurs in stars _________ ________________than
  those that produce novas
• Result from stars that are originally massive
  stars
• Occur from high ____________ and _____________
  that fuse carbon into magnesium and heaving
  elements and then into iron, with the explosion
  of iron creating the supernova
• Neutron star
• Collapsed _________ of a _________________
  consisting of a small, extremely dense ball of
  neutrons
• Rotates very rapidly
• A ______________ of matter from a neutron star
  would weigh 100 million tons on Earth

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Supernova
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Neutron star in the middle of a supernova
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --

• Pulsar
• Neutron star rapidly ________________ and emits
  two beams of radiation that sweep across space
• Radiation detected from pulsars is radio waves
• Black hole
• Hole in space with a gravity so great that not
  even light can escape it
• Formed by the ______________ of a very large
  supernova in which the force of the contraction
  of the white dwarf crushes the dense core of the
  star
• Observed from effects on companion stars and
  emissions of _________________
• May be at the cores of many galaxies

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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
Supernova and companion star
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
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Chapter 25 Beyond Our Solar System-- Section
25.2 Stellar Evolution --
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Chapter 25 Beyond Our Solar System
Section 25.3 The Universe
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• __________________________
• Large-scale groups of stars
• Bound together by gravitational attraction
• Typical galaxy
• About ____________________ light years in
  diameter
• Contains ____________ billion stars
• Contains dust and gas clouds
• Contain two kinds of bright nebulae
• Those that glow from the hot gases within
• Those that shine by reflecting the light of
  nearby stars
• __________ billion to __ _____________ galaxies
  in the known part of the universe

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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• _____________ ___________________
• Made up of the Millky Way Galaxy (our Galaxy) and
  17 other galaxies (/- 2) within 3 million light
  years of us
• Closest galaxies to Earth
• Large Magellanic Cloud
• Small Magellanic Cloud
• Galaxy cluster
• Cluster of galaxies
• The combined gravity of the galaxies in a galaxy
  cluster hold them together, primarily by mutual
  gravitational attraction.

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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
Local Group
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
Local Group
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• Types of galaxies
• ? ________________ galaxy
• Type of galaxy with a nucleus of bright stars and
  flattened arms that swirl around the nucleus of
  the galaxy
• ______________ ___________ central nucleus
• Galactic disk
• Codes for classifying spiral galaxies (S)
• Sa Large bulges, tight, almost circular, spiral
  arms
• Sb Smaller bulges and more open spiral arms
• Sc Small bulges and a loose, sometimes quite
  poorly defined spiral pattern
• Sd Even more poorly defined arms

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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
Models of Spiral Galaxies
Type Sa
Type Sb
Type Sc
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
M81 (Sa type galaxy)
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
M51 (Sb type galaxy) Whirlpool Galaxy
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
NGC 2997 (Sc type galaxy)
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• Spiral arms contain millions of young stars and
  gas and dust
• ___________________spiral galaxy
• Type of spiral galaxy with a bar of stars that
  runs through its center
• Code SB with SBa, SBb, and SBc based on bulge and
  tightness of the spiral pattern

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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
Models of Barred Spiral Galaxies
Type SBa
Type SBb
Type SBc
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
M81 (SBa type galaxy)
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
M95 (SBb type galaxy)
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
NGC 1365 (SBc type galaxy)
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• Types of galaxies
• ? ____________________ galaxy
• Type of galaxy with a very bright center that
  contains little dust and gas and is spherical to
  disk-like in shape
• Does not have spiral arms
• Has no young stars
• Codes for classifying elliptical galaxies (E)
• E0 nearly spherical
• E1 E6 variations of spherical shape
• E7 very flattened in shape

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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
Models of Elliptical Galaxies
Type E0
Type E4
Type E7
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
M87 (E1 type galaxy)
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
M59 (E5 type galaxy)
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• Types of galaxies
• ? Irregular galaxy
• Type of galaxy with no identifiable shape and an
  uneven distribution of stars within it
• Generally smaller and less bright that other
  types of galaxies
• Reasons for uneven distribution of stars
• ____________________________________________
• ____________________________________________
• ? Result of two galaxies colliding

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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --
M82 (Cigar Galaxy - an irregular galaxy)
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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• The Milky Way Galaxy
• Spiral galaxy about ____________ across and
  _____________ thick
• Arms Rotate around the nucleus of the galaxy,
  earth toward the end of one arm
• Contains two types of star clusters
• _______________ cluster
• Loosely shaped group of hundreds of stars
• Located in the arms of the disk
• _______________ cluster
• Spherically shaped group of hundreds of stars
  located around the core of the Milky Way Galaxy
• Contains more stars than an open cluster

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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• Mainly consists of two types of star systems
• __________________ star system
• Pair of stars that revolve around each other
• Caused by mutual gravitational forces
• Multiple star system
• Consists of more than two stars
• Revolutions of stars around stars different
• Revisiting the Big Bang Theory
• _______________________________
• Starlike objects that give off radio waves and
  X-rays
• Among the first objects formed after the big bang
  and seem to have evolved into galaxies
• 12 billion light years from Earth and seen on
  Earth as they appeared 12 billion years ago

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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• ________ ______________ ___________________
• Theory that all matter and energy in the universe
  were compressed into an extremely small volume
  that suddenly, 17 billion years ago, began
  expanding in all directions
• As the cloud expanded, galaxies formed and
  gravitational forces caused gases and other
  particles to converge.
• Argument against the big bang theory
• If the big bang had occurred, the energy left
  from the explosion would be found evenly
  distributed throughout the expanding universe.
• Big bang theory should not be accepted if the
  energy cannot be found.

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Chapter 25 Beyond Our Solar System-- Section
25.3 The Universe --

• Argument for the big bang theory
• ______________ _________________
• Low levels of energy evenly distributed
  throughout the universe
• Discovered in the 1960s using radio telescopes
• _________________ _____________
• Law that states that the galaxies are retreating
  from the Milky Way Galaxy at a speed proportional
  to their distance
• Reflects that the universe is_________________as
  a result of the big bang

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The Big Crunch?

• How will universe end?
• Expand forever?
• ______________ _________ _______________ back
  once again to a small size?
• Dark matter and dark energy
• Dark matter doesnt give off radiation, may
  make up 9/10 of the universe
• may be making the universe accelerate as it
  expands.