It appeared to validate the hypothesis by the German philosopher Immanuel Kant, 230 years ago, that our solar system was born when planets condensed from nebular material in the plane of such a disk. (hubblesite.org)
The percentages denote the amount of nebular light passing through the disk. (carnegiescience.edu)
H13CO + (J = 1 - 0) emission reveals peaks in both IRS 1 - 3 and IRS 9 regions, none of which are coincident with visible nebular emission, suggesting the presence of dense cloud nearby. (arxiv.org)