Shortly after quasars were discovered, scientists began to observe the quasar, and they discover something very unusual. They saw spectral emission lines where some quasars were previously, but they could not identify exactly what it was. In the 1960s, after careful observation, scientists concluded that those emission lines were formed by the quasar itself. The quasar, as scientists proposed, had undergone a tremendously large redshift(process of shifting the wavelength of emitted light of celestial bodies toward the red end of the visible spectrum). The result of this process, was a quasar that is going at speeds of 93% of the speed of light. Scientists concluded that this is one reason why the universe is constantly expanding.

There are many theories in the field of astronomy that explains what quasars are and how they are formed. One theory that has been postulated but not yet clarified is the idea that quasars are actually "galaxies at an early stage of the evolution" ("Quasar" 1).This theory based on careful observations of the redshifts quasars undergo.
Another theory that has been connected with what quasars are is that they may represent the bright nuclei of distant galaxies. Carl Seyfert proved this theory to some extent in 1943, when he identified a spiral galaxy that had a small but extremely bright nucleus and abnormal spectral features. Since then, quasars like 3C 48 and 3C 273 have been identified to have this property, and scientists also have concluded that they may be even embedded into a galaxy. Though this theory has been proven to some extent, scientists still say it has not yet been clarified.
Others think that quasars are stars that are travelling really at speeds near the speed of light. Still others think that quasars are supermassive moving black holes. Once again though, none of the theories presented are concrete. The main theory behind quasars is that they are connected with a "companion" galaxy. This means that a quasar would gain its energy from its "companion." IRAS045052958, for example, is a quasar that used and still is using energy formed from a galaxy collision. One theory that is widely
One particular theory about Quasars that has been proven was made by Albert Einstein in his theory of relativity. Called the Einstein cross, this theory states that a quasar emits energy through a high mass galaxy and the galaxy, acting like a mirror or a lens, produces several images of the quasar, and since the quasar is directly behind the galaxy, the image formed from this process is perfectly symmetrical from a viewer's point of view (Moore 200). Pictures of this have been taken from the Hubble Telescope.
One theory that has been proven answered the of why quasars undergo a redshift. One theory that is quite believable is that the speed at which the quasars are going at will cause a redshift. This theory was based on the idea of the Doppler effect, which states that "the shift in frequency of acoustic or electromagnetic radiation emitted by a source moving relative to an observer as perceived by the observer: the shift is to higher frequencies when the source approaches and to lower frequencies when it recedes" ("Doppler" 1).