1. Stars

2. Night sky above Arizona

3. Utah

4. Infinite Campus Update
Doppler Effect Lab (10pts.)
Expansion Theory Lab (10pts.)
Universe Quiz (25 pts.)
*Will take late work but points will be deducted.
*Notify if need RTI or Guided Study Hall (GSH)

5. Star Classifications How are stars classified? 1. size- amount of mass
2. luminosity-brightness of a star.
3. color – related to the energy emitted by a star.

6. Star Classification: Color
Seven main classes of stars based on color:
Which class has the hottest star? coolest star?
Which class does our sun belong in?

7. Temperature of Stars

8. Star Classification: Color
Scientist can determine the chemical make-up of a star by analyzing the unique color spectrums it emits off.
Each element emits a unique color spectrum.
Heavier elements 2 %
Carbon, Oxygen,
Nitrogen, & Calcium
Helium
29%
Hydrogen 69%

9. Star Classifcation: Brightness
Astronomers can classify stars by their brightness.
Brightness:
Apparent magnitude: Measure of how bright a star appears to be from earth.
Absolute Magnitude: Measure of a star’s true brightness by using a standard distance. (33 light years away)

10. Absolute Magnitude: Brightness of Stars
sciencephoto.com

11. Absolute Magnitude: Brightness of Stars
As temperature increases what happens to luminosity ?
As luminosity increases what happens to absolute magnitude?

12. Life Cycle of a Star: Stage One
Nebula:
Star begins as a cloud of
dust and gas.
Gravity holds the nebula
together.
Nebula phase can last for
thousands of years before
it becomes a protostar.
Eagles Nebula

14. Life Cycle of a Star: Stage One
Protostar:
When gravity increases the particles condense, heat up, and begin to spin around each other.
Creates a dense center region of particles.
Continues to grow in size and mass
Temperature to increase
Particles to spin faster.
Protostar phase:
100, million yrs.

15. Life Cycle of a Star: Stage Two Main Sequence Stage:
Where a star is born.
Light /energy is produced
Nuclear fusion: A reaction where 2 hydrogen atoms fuse together to form a helium atom.
The star is stable in size due to nuclear fusion.
Main-Sequence Phase: billions of yrs.
(longest phase for massive and average stars) /

16. Life Cycle of a Star: Stage Two Main Sequence Stage:
The star is stable in size due to nuclear fusion.
(gravitational force = nuclear force)

17. Life Cycle of a Star: Stage Two Main Sequence Stage:
Where a star is born.
Light /energy is produced
Nuclear fusion: A reaction where 2 hydrogen atoms fuse together to form a helium atom.
The star is stable in size due to nuclear fusion.
Main-Sequence Phase: billions of yrs.
(longest phase for massive and average stars) /

18. Life Cycle of a Star: Stage Three Red Supergiant/Giant:
* When hydrogen atoms are used up.
*Gravity increases causing center of star to condense.
*Nuclear fusion occurs with helium atoms producing carbon and oxygen atoms.
*Star becomes stable again.
*The outer gases expand & begin to cool.
* The star becomes 10 to 100 times bigger than our sun (GIANT)
* When the helium is gone, the star begins to die.

19. Life Cycle of a Star: Stage Three Red Supergiant/Giant:
* The star becomes 10 to 100 times bigger than our sun (GIANT)

20. Life Cycle of a Star: Stage Four
Average Star:
Planetary Nebula
*A cloud of dust forms around the dying star
White Dwarf
*Overtime the star shrinks and cools because helium has been used up.
*Can glow for billions of years.
*A nova may occur (explosion)
Black Dwarf
*All energy from helium fusion has left the star.

22. Life Cycle of a Star: Stage Four Massive Stars:
Supernova
A big explosion that quickly releases most energy and particles of the dying star.
Neutron Star
Remains of a supernova. Protons and neutrons smashed together into a tiny volume.
Black Hole
Extremely massive stars that collapse in on itself due to its own immense gravity.
Immense gravity will engulf any matter close to it.

24. Which planets are called the terrestrial planets?
astrobioloblog.wordpress.com
Which planets are called the terrestrial planets?
Which planets are called the gas giants?

25. Mercury
solarsystem.nasa.gov

26. Venus Venus with surface pictures below: MERCURY

27. Our Earth

28. Mars

29. Jupiter

30. SATURN

31. Uranus

32. Neptune

33. PLUTO – the “new” Dwarf, and its “moon”
Dwarf Planets:
Larger and more developed
than asteroids
Smaller than planets
Weaker gravitational force

34. Kuiper Belt Kuiper Belt; Space beyond Neptune where
Pluto and other dwarf planets have been observed.
Our Moon
Eris
Earth
Ceres
Pluto and its moon
Size comparison of Earth and some common dwarf planets.

35. Comets Comets: Composed of icy gases, rocks, and dust.
Called cosmic snowballs.
When orbits close to the sun, icy materials heat-up releasing dust and gases that creates the tail of the moving comet.
Comet NEAT taken in AZ in 2004

36. Asteroids and Asteroid Belt
Rocky, airless objects in space
Orbit the sun.
Smaller than planets
Asteroid Belt:
collection of asteroids
located between Mars and Jupiter
Around 10,000 asteroids
en.wikibooks.org

37. Meteors and Meteorites
A Shooting “Star”
Meteors:
Small chunks of rock and debris.
Known as shooting stars when fall through planet’s atmosphere.
Meteor pieces that make it to the solid layers of planets are called meteorites
earthsky.org
Meteorite found on Mars

38. astrobioloblog.wordpress.com