Describe the three things that can trigger star formation

Astronomy Writing Assignment

or this assignment use the information in Chapter 13 to answer the following questions

1.  Describe the three things that can trigger star formation  

2.  Explain what happens in the protostar and pre-main-sequence stage--what does it start with?  What are some of the physical processes that are happening?  Include some information about the T-Tauri stage.

3.  Describe what happens in the zero-age main sequence stage.  Make sure to address what hydrostatic equilibrium is.  Include some information about how long stars of various sizes stay in this stage.  

4.  Describe what happens on the giant stage.  Include information about hydrogen shell fusion and helium fusion.  

Each answer should be about a paragraph in length.  Make sure to answer the questions in your own words--I'm not looking for a word-for-word explanation from the book or the bullet points at the end of the chapter.

Each answer is worth up to 5 points.  The characteristics of a 5 point answer are:  

*The question is answered correctly (1-2 sentences)

*There is extensive is an elaboration to support/illustrate the answer (3-4 sentences)

*The spelling and use of conventions (capitalization, punctuation) is correct.  Proper grammar is used (sentences flow well when read aloud).