Protoplanetary Disk Artist’s Rendition of Brown Dwarf StarSelf-luminous object held together by its own self-gravity. Often refers to those objects which generate energy from nuclear reactions occurring at their cores, but may also be applied to stellar remnants such as neutron stars. surrounded by Swirling Protoplanetary Disc. Image Credit: NASA/JPL-Caltech Flattened and rotating disk of dense gas and dust/solids orbiting a young star from which planets can eventually form. Prominence Protostar