The theoretical images of a protoplanetary disk at 3 mm (left map) and 160 micron (right map). The angle between the axis of the disk and an observer is 75 degree.  The images are produced as a result of protoplanetary disk simulations with a hydrodynamical and radiative transfer models. To the right from the center one can see a dense fragment which is going to form a protoplanet. The disk is transparent in 3 mm so this fragment appears as a bright spot in the left map.  The optical depth of the disk is significant in 160 micron so the fragment manifests itself as a dark region on the right map.
<a href="//commons.wikimedia.org/w/index.php?title=User:Pavyar&amp;action=edit&amp;redlink=1" class="new" title="User:Pavyar (page does not exist)">Yaroslav Pavlyuchenkov</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>