Unformatted text preview: during the formation of stars. Starburst galaxies were first identified by this incredible amount of infrared light. Infrared light is the portion of the electromagnetic spectrum with wavelengths slightly longer than optical light that takes the form of heat. 3) Light moves at a finite speed. Why is this fact important when observing galaxies? There are two reasons, one is a light year equals the distance light travels over the period of a year. This is roughly equal to 5,865,696,000,000 miles. If you are viewing a galaxy that is one light year away, you are seeing it as it was one year ago, two light years, two years ago, and so on. The second reason is it helps to determine how far away the galaxy is....
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- Spring '09
- Electromagnetic spectrum, 5,865,696,000,000 miles, bright blue galaxy, Starburst galaxies