Review Sheet Test 2: [Return to Syllabus]

Review Sheet for Test 2, February 13th, 2007

Reading from Text Book, pages 225-223, 235 - 256, 258 - 277
Lecture Notes: Stars 5 - 7, Evolution 1 - 6, Death 1 - 5

The Hertzsprung-Russell Diagram
1) Why are most stars found on the Main Sequence? What do they all have in common?
2) Know luminosity classes and their location on the HR Diagram. Where are the massive stars?
3) What is fusion? What is the spectral type and luminosity class of our Sun?
4) The Mass-Luminosity Relationship: Why and for who does it exist? What is the sense of it?

Binary Star Systems
5) What is an Apparent Binary? Visual Binary? Spectroscopic Binary? Eclipsing Binary?
6) Why are binary stars important in astronomy? What's special about eclipsing binaries?

The ISM and Star Formation
7) What is the interstellar medium? What are the four main types of nebulae?
8) Give 4 evidences for the Interstellar Medium. How does it affect star light as seen at Earth?
9) Where do we see evidence of stars forming? How do stars form? What starts it?
10) A star generates energy with fusion reactions in its core. How do proto-stars generate energy?
11) What are T Tauri stars? Where do we find proto-stars and T Tauri's on the HR Diagram?

Stellar Clusters
12) What do all stars in a stellar cluster have in common that makes them useful?
13) How is the HR diagram of a cluster used to age clusters? Track stellar evolution?
14) Mass is most important characteristic for predicting a stars life and evolution. Why?

Stellar Evolution
15) What is hydrostatic equilibrium? How does the star *regulate* itself with nuclear reactions?
16) How will the Sun evolve on the HR Diagram? What's happening in the core?
17) What are the final stages of a solar mass star? What's a white dwarf? Where did it come from?
18) What about high mass stars? Why can't they end as Planetary Nebula/White Dwarfs?
19) Why does fusion stop once reaching an Iron core? How do massive stars die?

Stellar Death & Remnants
20) White Dwarf: Are they 'evolving'? What is the 1.4 Solar Mass, Chandrasakhar Limit?
21) Neutron Stars: Density? How do we observe Neutron Stars? Are all Neutron stars seen as Pulsars?
22) What is required to see a Pulsar? What happens to old Pulsars? What happens to old pulsars?
23) What's special about the Crab Pulsar? What's special about the Hulse-Taylor pulsar?

ESSAY QUESTIONS The 5 point essay question will be one of the following:

1) Draw an HR Diagram with X and Y axes properly labeled with appropriate units. Show the location of: The Main Sequence, Red Giants, Red Supergiants and White Dwarfs. Finally, where does one find Pre-Main-Sequence stars on the HR Diagram?

2) Describe the evolution of our Sun starting with its formation from a molecular cloud to its death as a stellar remnant. Use all the appropriate names for the Sun at the various evolutionary stages (Hint: there are 5).

3) What was so special about 1987A? (two reasons). Why are supernovae important for increasing the amount of heavy elements in the universe? (two reasons). How might a low mass star go Supernova?