Do Now! You have until

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Do Now!You have until

• List the following words in order from smallest
  to largest

Constellation Planet Solar System
Star Universe Galaxy

• How many of the smaller word can fit into the
  next word on your list?

Example If you thought stars were smaller than a
solar system you can say there are 1000 stars in
a Solar System.
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Galaxies

• A. Galaxies are very large groups of stars.
• B. Most contain 100s of billions of stars!

• C. They are classified by shape.

• 1. Spiral

a) Nucleus with Arms
b) The center is full of many yellow stars,
which makes it look like a nucleus.
c) Many spiral arms come out of the
nucleus.
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• 2. Elliptical

a) Spherical, without spiral arms.
b) The oldest stars are in this type of
galaxy.
c) No new star activity.

• 3. Irregular

a) Does not have a definite shape.
b) Could be the result of two galaxies
colliding.
c) The Megallanic Clouds are an example of a
irregular galaxy.
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III. Our Galaxy The Milky Way

• A. Spiral shaped

• B. 100,000 light years across.

• C. Our solar system is located in one of the
  spirals, 30,000 light years from the nucleus.

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E. The closest star in our galaxy, besides the
sun, is Proximi Centauri. (About 4 light years
away.)
Alpha and Proximi Centauri
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IV. How the Terms Fit Together

• A. A star and its planets A solar system!

• B. A group of stars A constellation!

• C. Billions of stars A galaxy!

• D. Several galaxies A Cluster!

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• 1. The cluster that the Milky Way is located in
  is called the Local Group.

• 2. The other galaxies in the local group are

• - Amdromeda ( Spiral)

• - Megallanic Clouds
• IRREGULAR

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Constellations

• A. Constellations are groups of stars that appear
  to form some type of pattern in the sky.

• B. Most of the time stars, in a particular
  constellation, do not have a relationship with
  each other.

• C. Most constellations are named after Greek and
  Roman mythological figures.

• D. Astronomers have divided the sky into 88
  constellations.

• E. Constellations give stars specific location in
  the sky.

• Ex. 1. Polaris is in the handle of Ursa Minor.
  (Little Dipper)
• Ex. 2. Betelgeuse is in the right shoulder of
  Orion.

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BETELGUESE
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Why are Constellations Useful?

• A. Used as landmarks to locate other objects in
  space.

• B. Were used by sailors and explores as a
  navigational tool.

C. USED FOR ENTERTAINMENT
D. USED TO KEEP TRACK OF TIME/SEASONS FOR TASKS

• Seasonal Changes

• A. Different constellations can be seen at
  different times of the year..

• i. Due to the Earths revolution around the Sun.

• Ii. Ex. Orion can be seen in the winter and
  spring . Pegasus can only be seen in summer and
  fall.

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• What is your Sign?

• A. Aries-

(March 21-April 19)

• B. Taurus-

(April 20 - May 20)

• C. Gemini-

(May 21 - June 20)

• D. Cancer-

(June 21 - July 22)

• E. Leo-

(July 23 - August 22)

• F. Virgo-

(August 23 September 22)
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• G. Libra-

(September 23 - October 22)

• H. Scorpius-

(October 23 - November 21)

• I. Sagittarius-

(November 22 - December 21)

• J. Capricornus-

(December 22 - January 19)

• K. Aquarius-

(January 20 - February 18)

• L. Pisces-

(February 19 - March 20)
www.astro.wisc.edu/.../ extra/constellations.html
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Circumpolar constellations

• B. Some Constellations can be seen all year long!

• These type of constellations are called
  circumpolar.

• Ex. Of circumpolar constellations are Ursa Major
  Ursa Minor (Big Little Dipper).

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The Life of Stars
I. Intro. to Stars
A. Star- hot, bright, sphere of gas.
B. Stars are classified by their luminosity.
1. Luminosity- How bright a star is.
C. There are many things that can affect stars
luminosity.
Distance Optics Size Stage of
Life Temperature
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D. Types of Magnitude

• 1. Apparent Magnitude- The luminosity of a star
  as we see it from earth.
• Apparent Magnitude tells you very little about a
  star.

2. Absolute Magnitude- The measure of a stars
actual luminosity. a.) A formula is used to
figure absolute magnitude out. b.) A chart of the
brightest stars is then made. c.) This chart
shows how luminous each star would look if they
were all the same distance from Earth.
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E. Star Color
1. Color Can indicate the estimated
temperature of a star.
a.) Red- (Coolest star) 3000-4000 K b.)
Yellow- (The Sun) 4000-7000 K c.) White-
7000-11,000 K d.) Blue- (Hottest Star)
11,000-60,000 K
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• II Life Cycle of Stars

A. Stars are born in nebulas.
B. Nebula- A rapidly condensing cloud of gas and
dust.
C. Star Pre-life Steps
1. Gases rapidly condense to star dust.
2. Masses form
3. Masses collide with others to form larger
pieces of star stuff.
4. Gravitational forces increase.
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5. This sets off a snow ball effect or chain
reaction.
6. One very large object collects most of the
star stuff.
7. Density increases.
8. Temperature increases.
9. Fusion begins to take place.
a.) Fusion- The process in which two atoms
fuse together to form another substance.

b.) In the suns case there were two atoms of
Hydrogen, which fused together to form Helium.

10. When fusion out put becomes balanced with
the gravity of the large object, a star is
born.
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• D. Life Cycle Steps

1. Main Sequence- The beginning phase of life
for all stars.
a.) Every Star has a main sequence.
b.) The star spends most of its life in this
phase.
c.) Fusion continues for billions of years.
d.) When a stars hydrogen begins to run out,
the star begins to enter its next phase.
e.) It can go in one of two directions
depending on size Red Giant Phase (Small
Medium stars) Super Giant Phase (Large
Extra Large stars)
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E. Small Medium Stars (low mass stars)
2. Red Giant Phase- Beginning stage of death for
small medium size stars.
a.) The fusion and gravity of a star becomes
unbalanced do to hydrogen running out.
b.) This makes the star collapse in on it self.
c.) Another round of fusion is triggered. This
time helium fusses together.
d.) The star swells to several times its
original size
f.) Remaining gas floats away as the star
cools.
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3. White Dwarf- The remaining core of a small
or medium star after the red giant phase is over.

a.) The stars weight during the red giant phase
will make the star collapse in on it-self.
b.) All that is left of the star now is a
collapsed core.
c.) About the size of earth.
4. Black Dwarf- The final stage of death of a
small or medium size star.
a.) After the stars core cools enough that its
luminosity is zero a star enters this phase of
life.
b.) All that is left is a tiny ball of lifeless
material
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F. Large X-Large Stars (high mass stars)
2. Super Giant Star Phase- A star enters this
phase when most of the stars hydrogen is used
up.
a.) This causes a Super Nova.
b.) Super Nova- A rapid expansion of the
star that appears to be an explosion.

c.) Gases eventually escape to form new
nebulas.
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3. Neutron Star Phase- The remaining core
after a super nova.
a.) Very small and dense. (10-15 Km across)
b.) Can be double its original density.
4. Pulsar Star Phase- A rapidly spinning
neutron star.
a.) It is spinning so fast that it looks
like little pulses of light are coming off of
it.
b.) Total collapse of the star is near when
it enters this phase.
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5. Black Hole Phase- This is the final stage
of death for a large/x-large star.
a.) A total collapse of the stars core
takes place.
b.) A black hole is extremely dense and has
a very high gravitational force.
c.) Almost nothing can escape its
gravitational pull. (not even light)