Brown Dwarfs and Super Planets

Red Giants, White Dwarfs, and Brown Dwarfs are all different kinds of stars. Brown dwarfs are actually not quite stars, but not quite planets, either. Brown dwarfs are somewhere in-between stars and planets. They are not big enough or heavy enough to shine the way most stars do. They are also much bigger than planets (even Jupiter, which is the biggest planet in our solar system). Brown dwarfs shine mainly in infrared light, instead of the visible light that is emitted by the stars we see with our eyes. The image at left is an artist's depiction of what a brown dwarf might look like.

Scientists believe that most of the matter in the Universe hasn't been discovered yet. They call this "dark matter" because they believe it exists, but is hard to see. Brown dwarfs might make up some of this "dark matter" because they are so hard to see with visible light telescopes. There may be many brown dwarfs out there that we have never seen. The Spitzer Space Telescope will be able to find plenty of brown dwarfs, and these might make up for some of the "dark matter" that scientists are looking for.

The Spitzer Space Telescope will also be able to look for "super planets," which can be seen by infrared eyes. Super planets are planets around other stars that are up to 100 times bigger than Jupiter (which is over 1000 times bigger than the whole Earth!). Scientists looking for other solar systems like ours around distant stars are very interested in finding these super planets. It is easier to find super planets, rather than smaller planets like Earth, because they are so big. Many scientists are really looking for the smaller planets, like Earth, but the presence of a super planet suggests that there might be other planets around the star, too. Hopefully the discovery of more super planets will lead to the discovery of some Earth-like planets around nearby stars.

      The relative size of the planets in our solar system (spacing not to scale).



What is the Spitzer Space Telescope? What is the Purpose of the Spitzer Space Telescope? What Will the Spitzer Space Telescope Do? Building the Spitzer Space Telescope