Assertion: nebula's star | /r/LocatedNear | protoplanetary disk
Facets:
Source sentences:
text: The disk concentrates at the core to form a star, which may be surrounded by a protoplanetary disk.
text: The nebula is home to about 2,000 extremely young stars that are still surrounded by protoplanetary disks, rotating disks of dense gas and dust that surround newly formed stars.