Answer Happy

1) What is a planetary nebuln? How are they formed and what type of stars become planetary sebula? 2) How were each of these elements formed in our Universe? HT Be-> F> Fe > Fe 3) Explain three reasons why it is dimoult to study star formation 4) Write the formula for Hubble's Law? What does this law say? How did it give rise to the Big Bang Theory? 5) Why do we think dark matter exists? How much dark matter seems to exist? 6) Compare and contrast Population I stars and Population II stars. (age, location, metals, orbits) 7) Explain why all elements heavier than iron must be formed during a supernova explosion. 8) Explain how astronomers determine what elements are in stars.
e) Describe and open, closed, and fat universe. Which do astronomers think we live in 10) What is hydrostato equilibrium? Why is it important in the Sun? How do we know the Sun is in hydrostatio equilibrium? What happens if the Sun is not in hydrostatic equilibrium? 11) Explain how the Sun gets its energy? Write the nuclear reaction. How does the formula E - mo help to explain how stars get their energy? 12) What causes high mass stars to go supernova? What is left after the supernova explosion? 13) Draw and label a Hertzsprung-Russell diagram. Label both of the axes. Indicate the locations of the main sequence, white dwarfs, glants, supergiants, and the Sun. 14) Draw and describe the lighthouse model for pulsars. 15) What is a white dwarf star? What supports the star against gravity?