Our Universe

1
Our Universe
Billions of galaxies made up of billions of stars
2
Our Own Solar System

• The Sun and the Planets that orbit it

3
The Sun Our StarThe closest star to Earth

• Medium size
• Yellow
• Main Sequence Star
• 150,000,000 Km (93 Million miles) away.
• 4.5 - 5 billion years old
• Will last about another 5 billion years
• Located near the edge of our disc shaped galaxy
  The Milky Way

4
The Suns Planets

• Celestial bodies that orbit a star

5
Our Milky Way Galaxy
6
CometsRocky material made of gas dust and ice
that orbit the sun
7
MeteorsSpace Rocks known as shooting stars when
they enter the Earths atmosphere.Become
meteorites when they hit the Earths surface
8
AsteroidsSmall rocky bodies known as minor
planetsOrbit the sun mainly between Mars and
Jupiter (asteroid belt)
9
StarsHuge bright balls of gas
10
What are Stars

• Gigantic spheres of gases held together by
  gravity
• Generate huge amounts of energy because of
  nuclear reactions of hydrogen and other elements.
• Radiate electromagnetic radiation.
• Light, heat and other forms of energy
• There are 100 billion stars in our own galaxy!

11
Stars

• The Sun is the closest star to Earth
  150,000,000 km away
• The next closest star is Proxima Centauri
  39,900,000,000,000 km away
• 4.2 light years
• Stars are extremely far away!!!
• The Sun is thousands of times closer to Earth
  than other stars

• The Sun
• Proxima Centauri

12
Light YearsUnit of measurement for distances in
Space

• The distance that light travels in one year.
• Light travels at about 300,000 km/sec.
• 186,000 miles/sec
• One light year is equal to 9.46 trillion km
  (9,461,000,000,000).
• 5.87 trillion miles (5,870,000,000,000)
• Light travels faster than anything else known to
  man.

13
Classifying Stars
Class Color Surface Temp. (degrees Celsius) Elements detected Examples of stars
O Blue Above 30,000 Helium 10 Lacertae
B Blue-white 10,000 - 30,000 Helium and Hydrogen Rigel, Spica
A Blue-white 7,500 - 10,000 Hydrogen Vega, Sirius
F Yellow-white 6,000 - 7,500 Hydrogen and heavier elements Canopus, Procyon
G Yellow 5,000 - 6,000 Calcium and other metals The sun, Capella
K Orange 3,500 - 5,000 Calcium and Molecules Arcturus, Aldebaran
M Red Less than 5,000 Molecules Betelgeuse,Antares
14
HertzprungRussel (H-R) Diagram- a graph that
shows the relationship between a stars surface
temperature and its absolute magnitude.
15
H-R DiagramAnalyze the graph!
16
Analyzing the H-R Diagram

• Brightest Stars
• Y-Axis
• Brightness
• Dimmest Stars
• Hottest Stars X-Axis Coolest Stars
• Temperature

17
Stages of a Stars Life Cycle
18
Nebulas Stellar Nurseries

• Giant clouds of gas and dust in space
• Where new stars are formed

19
GALAXIES

• Large group of stars in space held together by
  Gravity
• Classified by Shape - Sprial/Disc, Elliptical,
  Irregular Shaped

20
Spiral/Disc Shaped Galaxy

• Andromeda Galaxy

• Large center with spiral arms traveling around it
• Ex. Andromeda Galaxy and our Milky Way Galaxy
• Our Sun is located near the edge of the Milky Way
  Galaxy

21
Our Milky Way

• Sprial/Disc Shaped Galaxy
• 100,000 Light Years Across
• Black Hole at the center
• The Sun is near the edge of our galaxy in one of
  the spiral arms.

22
Elliptical Galaxy

• M 87 Galaxy

• Massive blobs of stars that have very bright
  centers
• Very little gas and dust
• Contain mostly old stars.

23
Irregular Galaxy

• Large Megellanic Cloud

• Dont fit into any other class.
• Have irregular shapes
• Contain mostly young stars and lots of gas

24
SupernovaDeath of a star by explosion
25
Black HolesGravity is so strong not even light
can escapeBelieved to be the center of most
galaxies
26
Theories on the Origin of the UniverseHow did we
get here?

• The Big Bang Theory states that the universe
  began with a big explosion.
• Steady State Theory - the universe has always
  been here and always will.
• There are many more theories

27
The Big Bang theory

• Most dominant theory
• States that the universe was created from a
  cosmic explosion that hurled matter in all
  directions
• Occurred about 13-14 billion years ago

28
Evidence that supports the big bang

• Cosmic background radiation
• radiation coming from all directions in space,
  believed to be left over from the big bang.
• The observable expansion of the universe (Red
  Shift).
• Galaxies are moving away from eachother

29
(No Transcript)
30
Spectroscopes/Spectrometers

• Used to gain information about properties of
  components in the Universe
• Shows differences in the elements that make up a
  star.

31
Electromagnetic Waves

• Light Waves that Astronomers can use to gain
  information about distances and properties of
  components of the universe.

32
Electromagnetic Waves

• Radio waves
• Microwaves
• Infrared waves
• Visible Light
• Ultraviolet waves
• X-Rays
• Gamma Rays
• Cosmic Rays

33
From lowest to highest frequency (energy)
34
Electromagnetic Waves

• Look up Electromagnetic Waves using your netbook.
• Define electromagnetic waves
• List all the electromagnetic waves in the
  electromagnetic spectrum
• Describe what each type of wave is used for by
  humans.