Quasars

[Key Words] [General] [How Were Quasars Discovered]

Key Words

General
Quasars are compact objects very far away from our galaxy. They are several billion light-years away. They are so bright that they shine brighter than 100 galaxies combined. Through a telescope, quasars looked rather close because they are so bright. During the 1960s however, astronomers started to learn the truth about quasars.

Quasars are believed to have formed from the collision of two distant galaxies. When this happens, one galaxy creates a black hole with a mass of about 100 million suns inside of the other galaxy. Stars, gas, dust, and everything else begins to get pulled into the black hole. The temperature rises to hundreds of millions of degrease as it emits gigantic amounts of radiation.

Quasars let us look very far back in time. Because they are so far away, it takes a very long time for the light that they emit to get here on earth. Because it takes so long, the light that we see now was actually emitted billions of years ago. We do not see the quasar as it is now, but as it was when the light left its surface. Some of these quasars are so old that the light we see today is actually from the edge of time.

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How Were Quasars Discovered?
It was in the early 1960s when the astronomer Allan Sandage noticed that a certain star was displaying an unusual spectrum. The spectrum of the star did not match any of the normal elements you would find on a star such as hydrogen ad helium. It seemed to be of an unknown element. The spectrum also seemed to have a red-shift to it, indicating that the object was moving away.

In late 1962, Dutch astronomer Maarten Schmidt viewed a quasar through the 200-inch Hale telescope at Palomar Observatory. He identified it correctly as a normal star with a high red-shift. He was able to determine that it was about two billion light-years away. This amount of distance is huge, even compared to the distance between galaxies. He realized that at that distance, the object couldn't be the size of a star. He thought that it would need to be as big as a galaxy. He measured the diameter of the object and learned that although it was only the size of our solar system, it was producing as much energy as 1 trillion suns.

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[Key Words] [General] [How Were Quasars Discovered]