Planets are thought to form in the circumstellar disks around young stars. Astronomers have simulated this with computer model, and have been able to replicate (to a pretty good extent) the formation of our solar system via the circumstellar disk around our sun when it was very young. Planet formation is evident around nearby young stars as well. The caveat is that we can not directly see the planet forming inside the disk. Instead, astronomers use infrared and radio data to infer the a gap in the disk, probably due to the formation of a planet. Recently, astronomers were able to catch a rare glimpse or what appear to be a circumstellar disk around a star that's been distorted due to the presence of a planet.
Now we can't see the planet directly, but the fact that the disk has a spiral shape and not a circular shape suggests that a planet has been gravitationally disturbing the disk material. The image was taken with the Subaru telescope, an optical and infrared 8.2m scope in Mauna Kea, HI. The light from the star has been intentionally blocked out in the image, so that we can see the disk glowing in infrared. The disk is bright in the infrared because it is colder than the star it surrounds. How are we able to see such a disk? It's a combination of the fact that the telescope is very large, it uses very high tech adaptive optics to remove atmospheric affects, and the star is relatively close to us (~450 ly away). Astronomers are not certain that these arms are due to planets, but modeling shows that planets do have the capability of causing such structure. More modeling observations will need to be done to confirm these ideas.
Image credit: NASA's Goddard Space Flight Center/NCSA
