A Black Hole Without a Horizon: What Next-Generation Telescopes Will See express
A bottomless well, but not quite. An ordinary black hole has a boundary, the event horizon, beyond which nothing returns. But what if you remove that boundary? That's exactly the kind of object, dubbed JMN-1, that astrophysicists modeled: a massive body born from stellar collapse, but without the impenetrable veil. Instead of a horizon, there's a naked singularity — a point where matter falls in and where the known laws of physics break down.
In the simulation, they aimed a stream of plasma at JMN-1, just like at the black hole in the center of galaxy M87. Around the singularity swirled a scorching disk threaded with magnetic fields, just like the ones astronomers see around real black holes. Matter didn't pile up outside or get flung away; it calmly made its way to the center. The accretion rate was about three millionths of the maximum possible — the same as predicted for a black hole of the same mass.
Today, this light is too dim for our instruments, but next-generation radio interferometers will be able to catch it. Then astronomers will have a reliable test: if something flickers at the center of the shadow, we're not looking at a black hole but at its bold lookalike without a horizon. So nature may have left us a clue on how to peer beyond the edge of our usual ideas — into that very well that turned out not to be bottomless.
The object JMN-1 gets its name from the initials of three physicists (Joshi, Malafarina, and Narayan) who came up with this exotic type of spacetime within standard general relativity.
The idea of a naked singularity is explored in William Sleator's novel "Singularity," where characters try to prevent such an object from appearing near Earth.