Cepheid variable stars are important to astronomy because

Use the graph below to describe the 4 basic life cycle steps of a low mass star by selecting the color of each region marked on the H-R Diagram. (The black diagonal line is considered one of the answer choices)      

Use the graph below to describe the 4 basic life cycle steps of a low mass star by selecting the color of each region marked on the H-R Diagram. (The black diagonal line is considered one of the answer choices)      

Use the graph below to describe the 4 basic life cycle steps of a high mass star by selecting the color of each region marked on the H-R Diagram. (The black diagonal line is considered one of the answer choices)    

Which of the following stars will live the longest on the main sequence?

Stellar spectra were originally classified using what lines?

Use the following table to answer the question. Star Apparent Magnitude (m) Absolute Magnitude (M) m-M Spectral Type 1 -1.46 1.46 0 F0 2 -0.72 -2.5 1.78 A1 3 0.12 -8.1 8.22 B8 4 0.41 -7.2 7.61 M2 5 -0.27 4.4 -4.67 G2   Which star is the coolest?

The main cause of the differences seen between the various types of stellar spectra is the difference in __________ from star to star.

All G-type stars have approximately the same

After the H-shell burning phase is going, what is the next main source of energy production for a star?