Ria Misra explains:

A new study puts the unified model of black holes, a.k.a the doughnut model, on trial and concludes that black holes are (disappointingly) perhaps not all shaped like a box of glazed donuts flung into the air. So what are they shaped like?

Black holes appear to have several different kinds of shapes. The unified model posits that the reasoning behind this is not that they are shaped differently, but that the perspective we're seeing them from shifts.

To put it another way, it's like if you looked at a doughnut (glazed, because presumably the jelly ones were already mysterious enough) from above versus viewing it straight on or from the side. How you see the doughnut may shift, but its essential shape remains exactly the same.

A new study out of JPL that will be published in a forthcoming article in Astrophysical Journal, though, looked at a survey of data from over 170,000 black holes and concluded that, even if black holes do indeed have a doughnut-shaped structure, that's still not quite enough to explain the shapes they're seeing.

To understand why, NASA suggests that you imagine flinging a box of glazed doughnuts into the air. Presumably, the distribution of the angles that you see those doughnuts from should be random. The distribution of how scientists were seeing shapes of black holes, however, were not random. Instead they were seeing that some shapes clumping together.

So what are black holes shaped like? We're still not quite sure. But perhaps we're a little closer.