ASTR 101 Lecture Notes - Lecture 17: Hubble Space Telescope, Red, Herstmonceux Castle

• School: Queen's University
• Department: Physics, Engineering Physics and Astronomy
• Course: ASTR 101
• Professor: David Alan Hanes

Document Summary

Theme 5 part 2 -- creating and understanding spectra. If you were to ask the average person what sort of object emits light, their answer would probably be something like a lamp, or a fire, the sun, the stars. The correct answer, though, is that all objects emit light of some sort -- but only those that are hot enough emit visible light. We"re going to consider the full spectrum of light. As we will discover, astronomers use all wavelengths, all colours of light, but not just to study familiar objects in different ways. It"s because some objects can only be detected at other wavelengths, so they"re essential for the full exploration of the universe. Here are a few quick examples: cool gas in dense clouds, the place where stars are being formed, gives off light at infrared and radio wavelengths not visible to the eye. Incidentally, one complication is that not all wavelengths of light reach the ground.