Do Now!Do Now!You have untilYou have until

List the following words in order from smallest List the following words in order from smallest to largest: to largest:

Constellation Planet Solar System

Star Universe Galaxy

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

““Galaxies”Galaxies”

A. Galaxies are very large groups of A. Galaxies are very large groups of stars.stars.

B. Most contain 100s of billions of starsB. Most contain 100s of billions of stars!!

C. They are classified by C. They are classified by shape..

1. 1. SpiralSpiral::

a) “Nucleus with Arms”a) “Nucleus with Arms” b) The center is full of many yellow stars, b) The center is full of many yellow stars,

which makes it look like a nucleus.which makes it look like a nucleus.

c) Many spiral arms come out c) Many spiral arms come out of the nucleus. of the nucleus.

2. Elliptical:2. Elliptical:

a) Spherical, without spiral arms.a) Spherical, without spiral arms.

b) The oldest stars are in this type of galaxy. b) The oldest stars are in this type of galaxy.

c) No new star activity.c) No new star activity.

3. Irregular:3. Irregular: a) Does not have a definite shape.a) Does not have a definite shape.

b) Could be the result of two galaxies colliding. b) Could be the result of two galaxies colliding.

c) The Megallanic Clouds are an c) The Megallanic Clouds are an example of a irregular galaxy. example of a irregular galaxy.

III. Our Galaxy: “The Milky Way”

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

B. 100,000 light years across. B. 100,000 light years across.

A. Spiral shaped A. Spiral shaped

E. The closest star in our galaxy, besides the sun, is Proximi Centauri. (About 4 light years

away.)

Alpha and Proximi Centauri

IV. How the Terms Fit Together:IV. How the Terms Fit Together:

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

B. A group of stars B. A group of stars = A constellation!= A constellation!

C. Billions of C. Billions of stars = A galaxy!stars = A galaxy!

D. Several galaxies D. Several galaxies = A Cluster!= A Cluster!

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

2. The other galaxies in the local group are : 2. The other galaxies in the local group are :

- Amdromeda ( Spiral) - Amdromeda ( Spiral) - Megallanic Clouds- Megallanic Clouds

IRREGULAR IRREGULAR

““Constellations”Constellations”

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

BETELGUESEBETELGUESE

Why are Constellations Useful?Why are Constellations Useful?

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

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

• Seasonal Changes:

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

• i. Due to the Earth’s revolution around the Sun.

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

C. USED FOR ENTERTAINMENT

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

• What is your Sign?

• A. Aries- (March 21-April 19)(March 21-April 19)

• B. Taurus- (April 20 - May 20)(April 20 - May 20)

(May 21 - June 20)(May 21 - June 20)• C. Gemini- • D. Cancer- (June 21 - July 22)(June 21 - July 22)• E. Leo- (July 23 - August 22)(July 23 - August 22)• F. Virgo- (August 23 – September 22) (August 23 – September 22)

G. Libra-G. Libra- (September 23 - October 22)(September 23 - October 22)

• H. Scorpius- (October 23 - November 21)(October 23 - November 21)

• I. Sagittarius- (November 22 - December 21)(November 22 - December 21)

• J. Capricornus- (December 22 - January 19)(December 22 - January 19)

• K. Aquarius- (January 20 - February 18)(January 20 - February 18)

• L. Pisces- (February 19 - March 20)(February 19 - March 20)

www.astro.wisc.edu/.../ extra/constellations.html

B. Some Constellations can be seen all year long!B. Some Constellations can be seen all year long!• These type of constellations are called

circumpolar.

Circumpolar constellationsCircumpolar constellations

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

“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 OpticsSize Stage of LifeTemperature

D. Types of Magnitude:D. Types of Magnitude:1. Apparent Magnitude- The luminosity of a star as we see it from earth. 1. Apparent Magnitude- The luminosity of a star as we see it from earth.

– Apparent Magnitude tells you very little about a star.Apparent Magnitude tells you very little about a star.

2. Absolute Magnitude- The measure of a star’s actual luminosity. 2. Absolute Magnitude- The measure of a star’s actual luminosity.

a.) A formula is used to figure absolute magnitude out.a.) A formula is used to figure absolute magnitude out.

b.) A chart of the brightest stars is then made.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.c.) This chart shows how luminous each star would look if they were all the same distance from Earth.

E. Star Color:E. Star Color:1. Color – Can indicate the estimated temperature of a star. 1. Color – Can indicate the estimated temperature of a star.

a.) Red- (Coolest star) 3000-4000 Ka.) Red- (Coolest star) 3000-4000 K

b.) Yellow- (The Sun) 4000-7000 Kb.) Yellow- (The Sun) 4000-7000 K

c.) White- 7000-11,000 K c.) White- 7000-11,000 K

d.) Blue- (Hottest Star) 11,000-60,000 Kd.) Blue- (Hottest Star) 11,000-60,000 K

• II Life Cycle of Stars:II Life Cycle of Stars:

A. Stars are born in nebulas.A. Stars are born in nebulas. B. Nebula- A rapidly condensing cloud of gas and dust.B. Nebula- A rapidly condensing cloud of gas and dust.

C. Star “Pre-life Steps”C. Star “Pre-life Steps” 1. Gases rapidly condense to star dust.1. Gases rapidly condense to star dust. 2. Masses form2. Masses form

3. Masses collide with others to form larger pieces of 3. Masses collide with others to form larger pieces of “star stuff”.“star stuff”.

4. Gravitational forces increase.4. Gravitational forces increase.

5. This sets off a “snow ball effect” or chain 5. This sets off a “snow ball effect” or chain reaction.reaction.

6. One very large object collects most of the “star 6. One very large object collects most of the “star stuff”.stuff”.

7. Density increases.7. Density increases. 8. Temperature increases.8. Temperature increases. 9. Fusion begins to take place.9. Fusion begins to take place.

a.) Fusion- The process in which two atoms a.) Fusion- The process in which two atoms fuse together to fuse together to form another substance.form another substance.

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

10.10. When fusion out put becomes balanced with the When fusion out put becomes balanced with the gravity of the large object, a gravity of the large object, a

star is born.star is born.

D. Life Cycle Steps:D. Life Cycle Steps:

1. Main Sequence- The beginning phase of life for all stars.1. Main Sequence- The beginning phase of life for all stars.

a.) Every Star has a main sequence.a.) Every Star has a main sequence.b.) The star spends most of its life in this phase. b.) The star spends most of its life in this phase.

c.) Fusion continues for billions of years.c.) Fusion continues for billions of years. d.) When a star’s hydrogen begins to run out, the d.) When a star’s hydrogen begins to run out, the star begins to enter its star begins to enter its next phase.next phase.

e.) It can go in one of two directions depending on e.) It can go in one of two directions depending on size:size:

* Red Giant Phase (Small & Medium * Red Giant Phase (Small & Medium stars) stars)

* Super Giant Phase (Large & Extra Large stars)* Super Giant Phase (Large & Extra Large stars)

2. Red Giant Phase- Beginning stage of death for 2. Red Giant Phase- Beginning stage of death for small & medium small & medium size stars.size stars.

a.) The fusion and gravity of a star becomes a.) The fusion and gravity of a star becomes unbalanced do to unbalanced do to hydrogen running out.hydrogen running out.

b.) This makes the star collapse in on it self.b.) This makes the star collapse in on it self.

E. Small & Medium Stars: (low mass stars)E. Small & Medium Stars: (low mass stars)

c.) Another round of fusion is triggered. This time c.) Another round of fusion is triggered. This time helium fusses helium fusses together.together.

d.) The star swells to several times its original sized.) The star swells to several times its original size

f.) Remaining gas floats away as the star cools.f.) Remaining gas floats away as the star cools.

3. White Dwarf- The remaining core of a small or 3. White Dwarf- The remaining core of a small or medium star after the red giant phase is over.medium star after the red giant phase is over.

a.) The stars weight during the red giant phase will a.) The stars weight during the red giant phase will make the star collapse make the star collapse in on it-self.in on it-self.

b.) All that is left of the star now is a collapsed core.b.) All that is left of the star now is a collapsed core.

c.) About the size of earth.c.) About the size of earth. 4. Black Dwarf- The final stage of death of a small or medium size star.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 a.) After the stars core cools enough that its luminosity is zero a star enters this phase of life.enters this phase of life.

b.) All that is left is a tiny ball of “lifeless material”b.) All that is left is a tiny ball of “lifeless material”

F. Large & X-Large Stars: (high mass stars)F. Large & X-Large Stars: (high mass stars)2. 2. Super Giant Star Phase- A star enters this Super Giant Star Phase- A star enters this phase when most of the phase when most of the

stars hydrogen is stars hydrogen is used up. used up.

a.) a.) This causes a Super Nova.This causes a Super Nova.b.) b.) Super Nova- A rapid expansion of Super Nova- A rapid expansion of the star that appears to be the star that appears to be

an an explosion. explosion.

c.) c.) Gases eventually escape to form Gases eventually escape to form new nebulas.new nebulas.

3. Neutron Star Phase- The remaining core 3. Neutron Star Phase- The remaining core after a super nova. after a super nova.

b.) Can be double its original density.b.) Can be double its original density.

a.) Very small and dense. (10-15 Km a.) Very small and dense. (10-15 Km across)across)

4. Pulsar Star Phase- A rapidly spinning 4. Pulsar Star Phase- A rapidly spinning neutron star. neutron star.

a.) It is spinning so fast that it looks a.) It is spinning so fast that it looks like little pulses of light are like little pulses of light are coming off coming off of it. of it.

b.) Total collapse of the star is near b.) Total collapse of the star is near when it enters this phase. when it enters this phase.

5. Black Hole Phase- This is the final stage 5. Black Hole Phase- This is the final stage of death for a large/x-large star. of death for a large/x-large star.

a.) A total collapse of the star’s core a.) A total collapse of the star’s core takes place.takes place.

b.) A black hole is extremely dense and b.) A black hole is extremely dense and has a very high gravitational has a very high gravitational force.force.

c.) Almost nothing can escape its c.) Almost nothing can escape its gravitational pull. (not even gravitational pull. (not even light) light)