Review for Midterm 1 Astronomy A105
Spring 2009 Dr. Edward Rhoads
1. The sun:
How dense is the sun?
What affect does the corona have on passing objects?
Is the sun a star? How bright is it compared to other stars?
What kind of threat do coronal mass ejections pose to the earth?
2. Spectroscopy:
How are emission, absorption, and continuous spectra created?
What can the spectrum of a star tell us about the star?
What else can we learn from spectra?
What does the energy of a photon depend on?
What is the sun mostly made of; how do we know?
What are the different types of light?
3. Births of stars:
How are stars born? When are they considered to be “born”?
How many stars are typically born in a group and how many groups are typically formed at once? Why?
How does spin affect the formation of a star?
What are stars formed from and how big is that object?
How does the mass of a star affect the time it takes to form?
4. Stellar energy:
Where does the energy from the sun come from and what process generates it?
Why do some stars use the CNO cycle while other ones that use the proton-proton chain (and which types of stars do which)?
Why is fusion so difficult to do even in the cores of stars?
How does the huge temperature dependence of fusion affect the different masses of stars?
Why does fusion generate energy?
5. Lives of stars:
What do stars do while in the “main sequence”?
How and why do mass affect the expected lifetime of a star?
What is the difference between the size of a star and the size of our galaxy?
6. Deaths of Stars:
What is the fate of the sun in about 6 billion years?
What will save the sun from utter collapse in the end of its lifetime?
What happens to stars > 8 time the mass of the sun at the end of their lives?
How are neutron stars supported from collapse?
What happens to the core of a star once it starts to form iron and why?
7. Relativity:
What are black holes?
What are black holes like?
What happens when you get very close to a black hole?
Why are black holes “black”?