Questions to Investigate by fjhuangjun

VIEWS: 5 PAGES: 22

									The Life Cycle of Stars




        Mr. Phillips      1
  It's a dark, clear, moonless night.
        You look up into the sky.
You see thousands of stars arranged in
       patterns or constellations.
The light from these stars has traveled
   great distances to reach Earth.
But what are stars? How far away are
     they? Are they all the same?
                 Mr. Phillips             2
  Questions to Investigate

• What is a star?

• How hot is a star?

• How bright is a star?

• Is our sun a star?

• What is the life cycle of a star?
                    Mr. Phillips      3
           Lesson Objectives
1.    Given a handout on the life cycle of stars with
     missing information, and given the opportunity to
     view a PowerPoint presentation on the content of
     the packet, the student will successfully fill in
     90% of the blanks correctly.

2.     Given a computer and internet connection, the
     student will successfully download the Our Place
     in Space worksheet on either his/her first or
     second attempt.

3.    Given the website
     http://www.ology.amnh.org/astronomy/, the
     student will successfully navigate the Internet
     to view 90 % of the Our Place in Space website
     without needing to ask for guidance more than
     once.               Mr. Phillips                   4
     Lesson Objectives (continued…)
4.    Given a “Our Place in Space” handout with
     questions to answer and blanks to fill in, and
     given access to the above-mentioned website the
     student will correctly answer at least 80% of
     the questions in the Our Place in Space handout.

5.    Upon successful completion of the prior
     objectives and given access to
     http://www.quia.com/tq/363411.html, the
     student will correctly answer 7 out of 10
     questions on an online quiz.


                       Mr. Phillips                 5
           What is a star?
• Stars are massive,
  glowing balls of hot
  gases, mostly
  hydrogen and
  helium.
• Stars come in all
  sizes, brightness,
  temperatures and
  colors.
                    Mr. Phillips   6
       How hot is a star?
• Water freezes       =          0 º Celsius (C)

• Hot summer day =               40 º C

• Boiling water       =          100º C

• A star              =          up to 3,000º C


                  Mr. Phillips                     7
How bright is a star?
                1. Luminosity
                   The larger a star
                   is, the more
                   energy it puts out
                   and the more
                   luminous
                   (brighter) it is.

                •      Brightness
                       The closer a star
                       is, the brighter it
        Mr. Phillips   appears.            8
      YES! Our Sun is a Star!
              Why is it so much bigger?
• The difference is
  distance.
• The other stars we see
  are light years away.
• Our sun is only about 8
  light minutes away.
• This is many thousands
  of times closer.
                        Mr. Phillips      9
          Life Cycle of a Star
              Nebula and then a star

• Starts as a cloud of dust and
  gas that gradually presses
  together – called a Nebula.
  – Also sometimes called a
    protostar.




                       Mr. Phillips    10
      Life Cycle of a Star
              A Star is Born

• A star is born. These are
  sometimes called main sequence.

• Stars at this stage are blue or
  bluish white.



                  Mr. Phillips      11
      Life Cycle of a Star
              The Star Ages



• As the star ages, it will cool and
  turn yellow.
• Most of a star’s life it is yellow
  (like our sun).



                  Mr. Phillips         12
         Life Cycle of a Star
           Star Becomes a Red Giant

• The star cools and swells up to a much
  larger size.
• It becomes a red giant – a star at old age.




                    Mr. Phillips          13
      Life Cycle of a Star
             A White Dwarf


• A white dwarf is created when a
  small red giant (about the size of the
  Sun) runs out of fuel, cools, and
  begins to contract under gravity.




                 Mr. Phillips          14
      Life Cycle of a Star
              A Black Dwarf

• Sometimes a white dwarf will simply
  run out of fuel and die – and become a
  black dwarf.

• All heat and light energy is gone.



                  Mr. Phillips         15
            Life Cycle of a Star
                 Novas and Supernovas!

• A nova is a star that suddenly
  increases greatly in
  brightness and then slowly
  fades away.

• A supernova exhibits the
  same pattern of behavior as a
  nova, but the explosion
  destroys or profoundly alters
  the star.             Mr. Phillips
                                         A supernova
                                                       16
Life Cycle of a Star
   A comparison to us!




         Mr. Phillips    17
                     Life Cycle of a Star
                              Let’s Review

         Mid-Sized
         Stars         Red Giant          Nova       White           Black
                                                     Dwarf           Dwarf


Nebula


                                                             Neutron
                                                             Star
    Massive            Supergiant        Supernova
    Stars
                                                             Black
                                                             Hole
                                    Mr. Phillips                             18
      Life Cycle of a Star
         Bigger isn’t always better!

• Stars that are small or average in
  mass, such as the sun, shine for about
  10 billion years.

• The most massive stars only live for
  about one million years because they
  yse up their hydrogen more quickly.

                   Mr. Phillips          19
              Vocabulary
nebula – cloud of dust and gas that gradually
  presses together
stars – massive, glowing balls of hot gases
luminosity – the larger a star is the more
  energy it puts out
white dwarf – created when a small red giant
  runs out out fuel, cools, and begins to
  contract under gravity

                    Mr. Phillips            20
            Vocabulary
black dwarf – when a white dwarf
  simply runs out of fuel and dies
nova – when a star suddenly increases
  greatly in brightness and then slowly
  fades away.
supernova – same as a nova, but the
  explosion is much bigger and alters
  the star

                 Mr. Phillips             21
The amount of information on
 stars and space available on
the web is out of this world!
             Click the logo to see a VERY COOL site
             put together by the American Museum
                        of Natural History.




       Hubble is a space telescope that has
       captured some amazing images of outer
       space. Click the logo above!

                Mr. Phillips                    22

								
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