Reference no: EM131127926

The H-R Diagram-

Question 1: The table below summarizes the relationship between spectral type, temperature, and color for stars.  Note the surface temperature of the stars in the table increases. 

Question 2: Complete the following table related to stellar luminosities.  All units are expressed in terms of the sun, or in solar units.  Remember that luminosity is proportional to radius squared and temperature to the fourth power.

Question 3:  Check the appropriate region of the H-R diagram corresponding to each description below. 

Question 4: Check the appropriate region of the H-R diagram corresponding to each description below.

Question 5: The equation below describes the luminosity of a star in terms of its radius and temperature.  Use this relationship between luminosity, radius, and temperature to explain why each of the four types of stars in the previous question is found at its respective location on the H-R diagram.

Question 6: Investigate the sizes of stars along the main sequence.  What are the relative sizes of stars near the top of the main sequence, the middle, and the bottom?   

Question 7:  What can you conclude about the masses of stars as you go from the bottom to the top of the main sequence?

Question 8: Use the results from the previous 5 questions to construct a "conceptual" H-R Diagram.  Use the Arrow drawing tool in Shapes under the Insert tab to draw arrows showing the direction in which variables are increasing.  Use the Scribble drawing tool or insert a text box (use 'Draw Text Box') to label each of the arrows. 

a) Draw and label (with an L) an arrow on the y axis showing the direction of increasing luminosity of the stars. (This has been completed for you.)

b) Draw and label (with a T) an arrow on the x-axis showing the direction of increasing surface temperature of the stars.

c) Draw and label (with an R) an arrow showing the direction of increasing radius on the diagram.  (hint:  this must be perpendicular to the isoradius lines.)

d) Draw and label (with an M) an arrow showing the direction of increasing mass for main sequence stars on the diagram.  (Note that this arrow only applies to main sequence stars, but that is about 90% of all stars.)

Question 9: Describe the characteristics of stars that are found in the instability strip.  You should cover their range of temperatures, colors, luminosities, and sizes. (Comparing them to the sun is useful.) What name do we have for variable stars near the bottom of the instability strip?  What name do we have for variable stars near the top of the instability strip?

Question 10: Describe the characteristics of the nearest stars (compare them to the sun). 

Question 11:  Do you think this type of star (like the nearest) is rare or very common among all of the stars in our galaxy?  Explain your reasoning.  Are any assumptions involved in your reasoning?           

Question 12: Use the tools of the H-R Diagram to support the views of one of the three students.  Why are most of the stars we see as the brightest in the night sky really that bright?   (Hint:  You may find the options labeled both the nearest and brightest stars and the overlap useful.)

Question 13: Do you think that these bright stars are very common (make up a large percentage of all stars in general)? Explain your reasoning.

Attachment:- H-R Diagram.rar