The phrase "dusty disc" refers to a circular shape made up of tiny particles or dirt that has gathered on a surface, creating a layer of dust. Full definition
Meanwhile, whatever material doesn't become part of the star starts to form other dusty discs, which become planets. (science.howstuffworks.com)
This collection of new SPHERE images is just a sample of the wide variety of dusty discs being found around young stars. (sciencedaily.com)
Evidence for such a planet grew stronger in 2006, when astronomers reported finding what appeared to be a second, smaller dusty disc around the star that was tilted slightly with respect to the main disc. (newscientist.com)