Science Proposal

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Science Proposal

• Introduction of the SUN

• Group leader-----Celia Lau
• Group members--Doris Chung
• Miu Ho
• Chris Yim
• Yuki Ho

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Introduction of the Sun

• Data of the Sun
• How big is the Sun?
• The temperature of the Sun
• The structure of the Sun
• The composition of the Sun
• Why does the Sun burn and give out heat?

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The data of the Sun

• Age 4.55 billion years
• Luminosity 1L (sun) 3.83 x 1033g
• ???
• Distance between the Earth About
  15,000,000km

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Some photos of the Sun

• Erupting Sun ----
• ------ Solar flares
• Sunspots------

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The temperature of the Sun

• The surface of the Sun ( photosphere ) About
  5,500 degree Celsius
• The center section of the Sun ( core ) About 160
  million degree Celsius

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The composition of the Sun

• The Sun made up by
• Hydrogen 75
• Helium 24
• Carbon, oxygen, iron, nitrogen and other gases 1

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The structure of the Sun

• Core
• Radiative zone
• Convective zone
• Photosphere
• Chromosphere
• conora

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• Photosphere---The outer layer of the Sun, that we
  can see. Its temperature is about 5500 ?C
• Radiative zone---Heat is spread out by radiation
  and stay here for a long time
• Convective zone--- Made up by many convection
  cells, their lifetimes are short, each is about 8
  minutes
• Core---The innermost section of the Sun, the Sun
  producing its energy here. The temperature is
  about 160 million C, it would be so hot to burn
  everything for miles around it

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Why does the Sun burn and give out heat??

• When the Sun is producing its energy, ( hydrogen
  turns to helium ) some chemical changes happened.
  The Sun keep shinning because of this changes and
  energy.

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Sunspots

• Sunspots are cooler areas on the surface of the
  Sun. Because they are "cooler" than the
  surrounding areas they appear darker.
• Sunspots are 3,000 degrees Celsius cooler than
  the rest of the Sun, but they are still a very
  hot 3,000 degrees Celsius.
• Sunspots have a varying lifetime they can last
  from a few days to a few months.
• While their sizes vary they can be as large as
  50,000 kilometers but can also be comparatively
  small 2,000 kilometers.

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• When a sunspot disappears on the western side of
  the Sun it will reappear on the eastern side in
  about two weeks.
• They may be areas of magnetic activity. The
  magnetism affects the heating process and
  produces cool spots.
• Sunspots may be as large as Earth and last from
  days to weeks. One recorded sunspot lasted
  eighteen months.
• Sunspots have two parts the darker inner part is
  named the umbra and the brighter outer part is
  referred to as the penumbra.
• Sunspots has approximately an 11-year
• cycle.

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Total Solar Eclipse

• As the moon starts to cover more and more of the
  Sun it looks like someone is taking a "bite" out
  of the western edge of the Sun. Gradually, more
  and more of the Sun disappears.
• .

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• During the first hour of a total solar eclipse it
  doesnt really get very dark here on Earth. It is
  not until the last several minutes before
  totality that daylight disappears quickly
• Most people don't realize it but the darkness
  produced by an eclipse is not as black as the
  darkness produced during the night.

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What will happen after 50 billion years??
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After 50 billion years

• It will use up its available hydrogen fuel and
  will change its structure
• The outer layer of it will expand and cool down,
  so that the sun will become a red giant star. It
  will expand and expand until to the Mars orbit.
• The Earth must disappear that time!

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• Never use telescope to observe the Sun
• Never watch the Sun directly over 30 seconds
• Never stand under the Sun for a long
  time
• Use a white and black film to
• watch the Sun

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