astronoy discussion#1

#1 Parallax is used as a tool to determine distances to stars. Describe how stellar parallax works. Also discuss what limits the effective range of the technique and the maximum distance that can be accurately measured. Do you believe the concept of parallax is unique to astronomy or is it used in other technical disciplines? Provide examples.( this is discussion, only two paragraph will be fine) and for this discussion , i need two different answer.

#2

1.

    

The Sun’s atmosphere has three layers. What are they called and what is their temperature?

     

                             

    

2.   Stars are identified with a spectral type. What are the spectral types from hottest to coolest?

                                    

      Which of the following spectral types is hottest:B0, B4

                                    

3.    
What is the structure of the H-R diagram? What does it tell us?

                                     

4.    
What star types are found in the “Instability Strip” of the H-R diagram? Describe their behavior.

      
                             

 

5.    
What determines if a Cepheid variable is a Type I or Type II?