Molecular cloud in protostar formation.

Protostar Quiz

• What is a protostar?

• Which environments do protostars typically form in? Be specific.

• When will gravity cause a protostar to collapse in on itself?

• Which three factors are important in determining Jeans Mass?

• Why do protostars stay relatively cool before collapsing?

• What does it mean when a protostar has become opaque?

• What is the process called in which protostars form into main sequence stars?

• Why do protostars heat up when their molecular cloud contracts?

• Which law is responsible for the increasing temperature in a contracting molecular cloud?

• When matter is absorbed by a protostar, what is formed?

• Name two reasons why protostars are difficult to detect.

• Why do stars generally form in clusters?

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Questions:  White Dwarfs

 http://imagine.gsfc.nasa.gov/docs/science/know_l2/dwarfs.html

http://whitedwarf.org/education/ask/

http://en.wikipedia.org/wiki/White_dwarf

• What is a white dwarf?

• What does a white dwarf look like?

• Who discovered the first white dwarf?

• How does a star become a white dwarf?

• What is Chandrasekhar’s limit?

• Why is there an upper limit to the mass of a white dwarf star?

• What is the difference between a red dwarf and a white dwarf?

• Why are white dwarfs very dim even though they are as hot as 10,000 K?

• What happens to a white dwarf as time passes?

• Why does increasing a white dwarf’s mass make it shrink?

• What is a typical white dwarf’s density?

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                                                                                                   by Sam Narby

Main Sequence Stars Question Sheet                                                                 Period 2

http://imagine.gsfc.nasa.gov/docs/science/know_l2/stars.html
http://www.astro.umd.edu/education/astro/stev/main_seq.html

http://www.astro.uiuc.edu/~kaler/sow/star_intro.html#classes

1. What is an important property that characterizes a Main Sequence Star?



2. If there is no hydrostatic equilibrium in a Main Sequence Star, what will happen?

3. Name two ways energy is carried by a Main Sequence star.



4. What is opacity and how does it relate to radiation?

5. What happens when opacity is too high?



6. Where are Main Sequence Stars on the Hertzsprung-Russell diagram?

7. What is the variable that makes a Main Sequence Star lower or higher on the diagram?



8. A Main Sequence Star is burning hydrogen into _________.

9. What percent of a star’s life is spent in the Main Sequence stage?

10. Name 3 stars that are currently in the Main Sequence Stage.