1. Good Day Sunshine

Observing the Sun

Astronomers could not obtain scientific understanding of the Sun until they developed techniques to observe the Sun indirectly with telescopes. Important new insights were obtained each time that a new part of the electromagnetic spectrum was observed in this way. Indeed, solar astronomy is primarily an observational science, that has both led to, and been driven by, revolutionary scientific discoveries. Early indirect observations of the Sun, using optical telescopes at visible wavelengths, allowed scientific study of the Sun to begin, showing that our star is a dynamic changing body. The development of optical spectroscopy permitted investigation of the magnetic fields, atmospheric motions, and composition of the Sun, as well as a new understanding of the internal structure of the atom and the chemistry of the cosmos. Radio telescopes provided a unique, high-resolution perspective of the changing, million-degree solar atmosphere, powerful explosions on the Sun, and violent activity that characterizes much of the Universe. The development of artificial satellites and other spacecraft then allowed scientists to study the Sun above the Earthís atmosphere, permitting a full and continuous view of the Sunís ultraviolet and X-ray radiation, and direct sampling of energetic particles and magnetic fields flowing from it.

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Copyright 2010, Professor Kenneth R. Lang, Tufts University