universe powerpoint by liuqingyan

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									Our Universe


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             Universe
                  TEKS
(8.13) Science concepts. The student knows
    characteristics of the universe. The
    student is expected to:
(8.13A) describe characteristics of the
    universe such as stars and galaxies.
(8.13B) explain the use of light years to
    describe distances in the universe.
(8.13C) research and describe historical
    scientific theories of the origin of the
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              Universe
            TAKS Objectives
Objective 5: The student will demonstrate
  an understanding of earth and space
  systems.
Components in the universe may also be
  included, such as stars, nebulae, and
  comets.
Characteristics of the universe such as stars
  and galaxies may be integrated with all
  grade 8 objectives to make them more
  relevant.                                   3
                 Universe
          All space and the matter space
                     contains
                 The Big Bang Theory is one
                 theory of the formation of the
                 Universe. It states that the
                 universe began with a
                 tremendous explosion




http://hrw.com
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            Universe
                contains:
1.   Galaxies
2.   Stars
3.   Nebulae
4.   Quasars
5.   Comets

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          Galaxies
 There are three main types of
  Galaxies
 –Spiral
 –Elliptical
 –Irregular

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                    Galaxies
    Spiral
         – Characterized by a bulge at the center and
           spiral arms
         – Spiral shape is caused by the rotation of the
           galaxy




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http://hrw.com
    Elliptical
                    Galaxies
         – Characterized by a very bright centers and
           very little dust and gas
         – Appear elongated or spherical and are
           basically massive blobs of stars
         – Composed of mostly old stars




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http://hrw.com
                   Galaxies
    Irregular
         – Galaxies that do not fit into any other
           class
         – As their name indicates they have
           irregular shapes




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http://hrw.com
           Stars
 Composition
 Brightness
 Temperature
 Mass
 Life Cycle

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              Stars
Composition
 –Made up of different elements in the
  form of gasses
 –When viewed through a spectrograph
  the specific gasses can be identified
  through an absorption spectrum
  which is a continuous spectrum with
  dark lines where less light gets
  through.
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                 Stars
  Composition




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http://hrw.com
                Stars
Brightness
 –Apparent Magnitude – how bright a
  star looks from Earth
 –Absolute Magnitude – how bright a
  star actually is
   (How bright the star would appear to the
    human eye if it were at a distance of 10
    parsecs from the earth)

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                   Stars
    Temperature
     Determined by the color of a star
     Classified by the following letter
      categories (O, B, A, F, G, K, M)




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http://hrw.com
                                            http://hrw.com
                     Stars
The Hertzsprung Russell Diagram (H-R) is a graph
showing the relationship between a star’s surface
temperature and its absolute magnitude




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                    Stars
Illustrating the relationship between temperature
                   and brightness




                                              16
http://hrw.com
                           Stars
   Mass
    Single most important determiner of a
     stars life cycle
    High Mass
    Low Mass




http://www.enchantedlearning.com/subjects/astronomy/stars/lifecycle 17
                               Stars
                 Illustrating the relationship between
                         mass and star life time




                                                         18
http://hrw.com
                             Stars
      Illustrating the relationship between mass and brightness




                                                                  19
http://hrw.com
                         Nebula
 Latin for “Cloud”
    Giant clouds of gas and dust
    Where new stars are formed
    Found in spiral galaxies
    Not found in elliptical galaxies




http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-astro-nebula.html   20
                              Quasars
 The most powerful energy source in the
  universe
 May be the core of young galaxies forming
 Among the most distant objects in space from
  Earth




http://hubblesite.org/newscenter/newsdesk/archive/releases/category/galaxy/quasar_active%20nucleus/   21
                  Comets
 A comet is made of dirty ice, dust, and gas.
 When a comet gets close to the Sun, part of the
  ice starts to melt. This lets the dust and gas out.
 Solar winds then push them away from the
  comet. This makes the comet's tail.
 Every time a comet comes close to the Sun, a
  part of it melts. Over time, it will completely
  disappear.
 A comet does not give off any light of its own.
  Ice in the comet acts just like a mirror. What we
  see is sunlight bouncing off the comet.

  http://www.nasa.gov/audience/forkids/home/F_SC_comet.html 22
                Comets



                                        Halebopp Comet




http://www.nashttp://deepimpact.jpl.nasa.gov/science/comets.html
                                                            23
Looking through the center of the Milky Way




http://www.nashttp://deepimpact.jpl.nasa.gov/science/comets.html
                                                            24
 Questions and Discussion
1. Which characteristics are used to
  classify stars?
    A. temperature
    B. brightness (magnitude)
    C. mass
    D. All of the above




                                       25
 Questions and Discussion
1. Which characteristics are used to
  classify stars?
    A. temperature
    B. brightness (magnitude)
    C. mass
    D. All of the above




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      Questions and Discussion
  1. Temperature and brightness are both used to
        classify stars as seen on the HR diagram, but
        mass is also important because it determines
        a stars temperature and brightness.




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http://hrw.com
   Questions and Discussion
2. If a star becomes a black hole at the
 end of its life, it is a?
   A. high mass star
   B. nebula
   C. low mass star
   D. All of the above




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   Questions and Discussion
2. If a star becomes a black hole at the
 end of its life, it is a?
   A. high mass star
   B. nebula
   C. low mass star
   D. All of the above




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       Questions and Discussion
  2. Becoming a black hole would mean that the
    star was a high mass star, giant actually as
    seen in the following illustration.




http://www.enchantedlearning.com/subjects/astronomy/stars/lifecycle 30
  Questions and Discussion
3. Galaxies are classified based on
    their?
   A. composition
   B. color
   C. shape
   D. All of the above




                                      31
  Questions and Discussion
3. Galaxies are classified based on
    their?
   A. composition
   B. color
   C. shape
   D. All of the above




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         Questions and Discussion
    3. Galaxies are classified based on their
       shape. This is evident because of their
       name categories. The categories of
       galaxies are spiral, elliptical and
       irregular.




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http://hrw.com
  Questions and Discussion
4. Scientist believe that quasars give
 off as much light as 10 trillion suns
 because of their?
   A. composition
   B. distance and brightness
   C. shape
   D. color



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  Questions and Discussion
4. Scientist believe that quasars give
 off as much light as 10 trillion suns
 because of their?
   A. name
   B. distance and brightness
   C. shape
   D. color


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         Questions and Discussion
    4. Scientist know the absolute brightness of
      a quasar known as PKS 0637-152, and
      they know that it gives off as much light as
      10 trillion suns because of its calculated
      distance using parallax.




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http://hrw.com

								
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