Granted, there is not enough dust in the ice cores to support this theory... but it is plausible and it does not require any positive feedbacks. (mc-computing.com)
He believes there wasn't quite enough dust around the star for the clearing - out process to make total sense. (discovermagazine.com)
When enough dust ends up in the same region, gravity can pull it together, creating the seeds of matter needed to build a new sun. (sciencenewsforstudents.org)