Different stages of the cycle gives off different wavelengths of light because more types elements are being made as you go farther down the cycle. So looking at the wavelengths that the light gives off can determine what stage a star is currently in
Observations are used in order to collect data and record a variety of interesting or useful key points about the subject or specimen in observation. These observations, if made well, can be recorded and used to supplement a hypothesis.
Dna is the way to answer this questions
