Spiral patterns are a common site throughout the natural world, but in the cosmos we usually associate them with galaxies. But now it appears that young stars, still forming their dust disks into planets, may have spiral arms as well. Astronomers studying a previously known disk around the star SAO 206462 were surprised to see that the dust had been swept into an unmistakable spiral arm pattern.
SAO 206462 is a well studied system, as it is a young star with a prominent dust disk. Astronomers know that if their current ideas about where planets come from are correct, then we have caught this distant star in the process of forming a brand new solar system. Carol Grady and her colleagues in the SEEDS (Strategic Exploration of Exoplanets and Disks with Subaru) study have been using the Subaru telescope in Hawaii to study the disk in detail, hoping to spot gaps which would indicate the presence of protoplanets. Instead, they were very excited to see the prominent spiral arms. Since the pattern is not symmetrical, each arm is likely associated with its own infant world.
For more information, read NASA’s summary of this discovery.