False color image of two gas giant protoplanets that have formed quickly in a disk of gas and dust. Each of the two protoplanets (yellow-red blobs) contains several Jupiter-masses of gas and dust. They orbit at distances of about 5 and 10 times the Earth's distance from the Sun in this theoretical model, at the orbital distances of Jupiter and Saturn in our own solar system. The protoplanets sweep up all the gas close to their orbits, leaving behind empty gaps (black) in the disk (purple). A solar-type star lies unseen at the center of the disk. These protoplanets formed in about 1000 years by the fastest known mechanism, the disk instability mechanism. If this star had a close binary star companion, these protoplanets might well be ejected outward from these otherwise stable orbits.
Credit: A. Boss (Carnegie Institute of Washington)