Stars and constellations

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Stars and constellations

• "To know ourselves, we must know the stars."
• Fourth Grade
• Miss Goldstein

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What are stars
Hot bodies of glowing gas.

• The color of a star is determined by its
  temperature. The hottest stars are blue and the
  coolest stars are red.

• Star is a ball of gas held together by its own
  gravity. The force of gravity is continually
  trying to cause the star to collapse.

They vary in size, mass, and temperature.
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The life of a star
Stage 1-
Stars form from huge cosmic space gas clouds.
They group into a huge ball of gas and dust.
Stage 2 -
Stage 3
As the cloud gets smaller it loses some of the
energy stored and will begin to heat up and glow.
The heat can reach 15 million degrees centigrade.
Because of the heat hydrogen will start to turn
into helium.
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The life of a star 2 of 3
Stage 4
The star begins to release energy, stopping it
from contracting even more and causes it to
shine. It is now a Main Sequence Star.
Stage 5 -
The helium core now starts to contract further
and reactions begin to occur around the core.
Stage 6 -
A star of one solar mass remains in main sequence
for about 10 billion years, until all of the
hydrogen has fused to form helium.
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Stage 7 -
The core becomes hot enough for the helium to
form carbon. The outer layers begin to expand,
cool and shine less brightly.
Stage 8 -
The helium core runs out, and the outer layers
drift of away from the core as a gaseous shell.
Stage 9 -
The remaining core (thats 80 of the original
star) is now in its final stages. The core
becomes a White Dwarf the star eventually cools
and dims. When it stops shining, the now dead
star is called a Black Dwarf
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A shooting starIS NOT A STAR

• It is a tiny bits of dust and rock called
  meteoroids falling into the Earth's atmosphere
  and burning up.

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The SunThe sun is our own special star yet, as
stars go, it is a very average star.

• The sun is made up of
• 75 hydrogen
• 25 helium
• Less than 1 oxygen and several other elements.

1,400,000 km (840,000 miles)

• In the daytime, our Sun,
• dominates, its brilliant
• light washes away the
• other stars .

The sun is not on fire. Think of the metal inside
a toaster, which glows even though it is not on
fire.
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Star vs Planet
The basic difference between a star and a planet
is that a star emits light produced in its
interior by nuclear 'burning', whereas a planet
only shines by reflected light.
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The North StarPolaris
The Earth's axis points within one degree of
Polaris. It is the brightest star in the
constellation Ursa Minor (also called the Little
Bear or the Little Dipper). Polaris looks like
it doesnt move in the sky but that all other
stars revolve around the North Star. It moves a
little through several thousands of years.
To find Polaris in the sky, locate the Big Dipper
and follow the two stars at the end of the basin
upward. This should lead you directly to Polaris.
It is the last star in the tail of the Little
Dipper.
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What are constellations?
constellations are named patterns of stars

• They have been given names by ancient astronomers
  because of the way they look. The patterns look
  the same today as they did when they were first
  named 3000 years ago

While the constellations do not look like they
are moving, they are. Due to their distance from
the Earth it will take thousands of lifetimes to
see significant changes in the star patterns.
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Now we will read

• Zoo in the Sky by Christina Balit to help us
  visualize constellations.

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Ursa MajorThe Big DipperThe Big Bear
One of the easiest to find groups of stars, the
Big Dipper is not a constellation, but rather a
part of the constellation Ursa Major.
3rd largest constellation
Can you see the Big Dipper in the picture above?
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Ursa MinorThe Little DipperThe Lesser Bear
Ursa Major is a fainter version of the Big Dipper
(or Plough, in the UK), and is home to the North
Star.
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Now we will read

• Once upon a Starry Night by Christina Balit

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ORION
Orion is the master of the winter skies. He lords
over the heavens from late fall to early spring,
with his hunting dog Sirius trailing at his feet.

The constellation's main feature is the three
stars which form the "belt" across the middle of
Orion from west to east Mintaka, Alnilam, and
Alnitak.
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GEMINI
The Twins, are really only half-brothers. They
share the same mother (Leda) but have different
fathers.
Castor (alpha Geminorum) is the slightly dimmer
star. Pollux is the brighter of the two stars
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CASSIOPEIA
The queen was both beautiful and vain, and the
story of how her vanity caused great distress is
told in relation to the constellation Andromeda.
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Create our own constellations

• What you need
• black 35mm film canisters, Scissors, Tape,
  Pushpin, Patterns (next slide)
• .Put a piece of tape on the side of each
  canister. Write the name of a constellation on
  it.
• Cut out a constellation pattern on the dotted
  lines.
• Put the pattern on the canister with the correct
  name on it.
• Put a pattern over the bottom of the film
  canister. Line the dark circle up with the inside
  rim of the canister. Tape the circle into place.
• Punch a small hole through the paper and the
  canister for each star in the pattern.
• Hold the film canister up to the light. Look
  through it to make sure that you have punched the
  holes all the way through. You should see light
  through each hole.
• Take the paper pattern off the canister.

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