Quasars
Quasars remain something of a mystery in the annals of astronomy. They were first discovered through the invention of the radio telescope. First class people search by SSN While we have made many significant discoveries through the use of visible light telescopes over the centuries, that part of the electromagnetic spectrum is very small and only tells one part of the story. There is a wealth of cosmic information wrapped up in X-rays, infrared light, and radio waves. To capture information in the form of radio waves, large antennas that look like a satellite dish were built. The early use of radio telescopes led to the discovery of points in the sky that emitted a steady stream of radio waves. Turning their visible light telescopes to these radio wave sources, astronomers discovered tiny specks of light like a star. They became known as "quasi-stellar radio sources" or quasars for short. With advances like the Hubble Space Telescope, astronomers have determined that quasars are most likely the very bright centers of very distant and very old galaxies. No one is quite sure what makes these galactic centers very bright. The current theory is that at the center is a supermassive black hole, more than the mass of a billion stars. This black hole swallows gas and other matter. As it falls into the black hole, this matter heats up and gives off light. It is possible for a quasar to "shut off" due to a lack of material falling into the black hole or some alteration in the black hole. Quasars are very fascinating. By studying them, we can learn more about the effects of black holes and the early stages in the life of a galaxy. For more information on quasars, consult the following links:
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