This isn't an Einstein Ring, where gravitational lensing can make a star look like a donut. https://en.m.wikipedia.org/wiki/Einstein_ring https://en.m.wikipedi

This isn't an Einstein Ring, where gravitational lensing can make a star look like a donut. https://en.m.wikipedia.org/wiki/Einstein_ring https://en.m.wikipedia.org/wiki/Einstein_ring This is more like a ring galaxy, formation models of which usually involve a fast, dense galaxy smashing through the center of another, leaving behind a compact core and a turbulent, distant ring of active star formation. https://en.m.wikipedia.org/wiki/Ring_galaxy https://en.m.wikipedia.org/wiki/Ring_galaxy Ring galaxy is an analogy. Another might be a ring of low pressure around the rapidly rising column of a mushroom cloud. https://en.m.wikipedia.org/wiki/Mushroom_cloud https://en.m.wikipedia.org/wiki/Mushroom_cloud https://en.m.wikipedia.org/wiki/Vortex_ring https://en.m.wikipedia.org/wiki/Vortex_ring https://youtu.be/zzQGMvIFD9o&t=15s https://youtu.be/zzQGMvIFD9o&t=15s And alas, this phenomenon does not include any actual donuts... although if there's enough money at the end of the month, your next astronomy department colloquium might feature some, if you arrive early.