Observing Stars Our view of the sky at night is possible because of the emission and reflection of light. 'Light' is the better-known term for the electromagnetic spectrum, which includes waves in the visible, ultra-violet, infra-red, microwave, radio, X-ray and gamma-ray regions. The scale of the spectrum is so large that no region is distinct, several overlap each other. Each of these regions in the electromagnetic spectrum represent transverse waves, travelling as electrical and magnetic …showed first 75 words of 2736 total…

…showed last 75 words of 2736 total…e can learn how stars evolve from our observations, however we can only view a tiny part of history. Star populations are mapped on the Hertzsprung-Russell diagram, basically a graph of luminosity against surface temperature: From it we can examine the life sequences of a star, deduce a star's absolute magnitude, and then their spectral class according to their surface temperature and other properties. We can identify what stage in its life a star it.