1. Learning Goals:
4. Complex Knowledge: demonstrations of learning that go aboveand above and beyond what was explicitly taught. 3. Knowledge: meeting the learning goals and expectations. 2. Foundational knowledge: simpler procedures, isolated details, vocabulary. 1. Limited knowledge: know very little details but working toward a higher level.
How do stars differ from moons and planets, and from one another?
How does the classification of stars help us understand how they evolve over their lifetimes?
What are the different types of stars?
What happens when different types of stars die?
Why is it important for us to understand stars?

2. Bell Work
How can you tell how a star will change throughout it’s life cycle? (what characteristic(s))

3. Test on the Friday after we get back
Tomorrow (Tuesday) is the LAST day to turn in an assignment that is late.
THE LAST DAY

4. Calculate – lifetime of a star
The lifetime of a star is inversely proportional to its initial mass.
Bigger Stars = Shorter Lives
Smaller Stars = Longer Lives
L~ 1/ M2.5
L= Lifetime in solar lifetimes (10billion years)
M= Mass in solar masses
L~ Lifetime = 1/ M2.5
M~0.5 solar masses
M~20 solar masses
5.66 solar lifetimes or billion years
solar lifetimes or 5.6 million years

5. Variable Stars Intrinsic Extrinsic Pulsating Variables
Consistent - Cepheid and RR Lyrae Stars
Galactic Measuring Tape
Semi regular
Eruptive
Type 1 supernova
Nova
Extrinsic
Eclipsing binaries
Rotating variables

7. Variable Stars
The time it takes to complete a cycle of maximum brightness to minimum brightness then back to maximum is called the period of the variable star.
Plotting the period produces a light curve, which can be studied to determine
Magnitude of stars
Distance from earth

10. Variable Stars
1. what are the periods of the four stars?

11. m - M = 5 log d - 5 d = 10(m - M + 5)/5 parsecs
If an astronomer observed a Cepheid star with period of 34 days, comparing to previously measured Cepheids, its absolute magnitude is If its apparent magnitude was +23.0, the astronomer could use the distance modulus equation:
m - M = 5 log d - 5
rearranged:
d = 10(m - M + 5)/5 parsecs
to find the distance to the Cepheid:
d = 10(23   + 5)/5 parsecs
d =  parsecs
d = 5.4 × 106 parsecs

12. Death Star
New Topic

13. I mean… Death OF A Star!

14. what happens to the core? – cosmic balancing act
Star core < 1.4 solar masses (Chandrasekhar Limit)
Planetary Nebula
Electron degeneracy
1 tablespoon of matter = 10 tons
Becomes white dwarf
Star core > 1.4 but < 4.5 solar masses
Supernova
Neutron degeneracy
1 tablespoon of matter = 250,000 tons
Becomes neutron star
Star core > 5 solar masses
Becomes a black hole

15. It is difficult compare the relative sizes of black holes, neutron stars, white dwarfs, the Sun, and red supergiants on the same sheet of paper. Their size differences are so vast. If you represent the diameter of a three-solar-mass-black hole or its event horizon by a dot 1/64 of an inch across, the size of a 1.4-solar-mass neutron star would be only slightly larger. But the size of a white dwarf would be about one foot, that of the Sun would be 38 yards, and that of a red supergiant, such as Betelgeuse, would be 22 miles. The true sizes of these objects range from 10 miles for a three solar mass black hole to 875,000,000 miles for Betelgeuse.

16. Planetary Nebulae Planetary Nebulae -
are the remnants of stellar death.
can be uniform and spherical or more complicated structures
Form when a star expands too much, and gravity drops and isn’t strong enough to hold on to the outer layers of the star. (paraphrase)
The gas is ionized by the star’s radiation, so it glows
Have a white dwarf star core

19. Green Bubble Nebula

20. Planetary Nebulae Exit Ticket
Create an information page about your nebula.
Include:
1 picture/sketch
2 facts about your nebula in particular
2 general facts about planetary nebulae
1. Cat’s Eye
2. Helix
3. Ring
4. Ant
5. Hourglass
6. Bug
7.Dumbbell
8. Eskimo