On November 1st, 2019 a paper was recently published in Science on A noninteracting low-mass black hole–giant star binary system named J05215658(which is totally the best name ever!) which presented the results of finding the first naked black hole using a predictable methodology. I'm not on this paper, nor did I take any data the paper used. However, I have operated the Tillinghast telescope which was used to take some of the data in the paper and also know one of the authors on the paper. They spent years working on it, with all the authors having to keep tight lips because it was such a cool discovery.





However, it fell kind of flat when it came to news coverage, with some articles kind of missing the point as to why it was such a cool discovery. This is honestly a real bummer (especially considering the huge amount of effort that went into it) and because I feel it deserves more love and attention than it got, I have decided to shed some light on the topic myself.





What a Naked Black Holes is

First off, what is a black hole in general? I won't go into a ton of detail, but it's basically a bunch of mass that has been compressed beyond what is known as the "Schwarzschild Radius". When that happens, gravity from the black hole becomes so intense that not even light can escape, hence the name black hole. Because light cannot escape, black holes literally become the blackest objects in existence and beyond theorized 'Hawking radiation' (which comes from a quantum mechanical effect) no amount of light will ever be emitted from them.

A computer simulation of a black hole which you can find on NASA's website. I've used this picture as it is a more accurate depiction of what was discovered. The reason I say it is an accurate depiction is because you can 'see' this black hole only because of the black hole it leaves in the image along with the inherent light distortion.

Image Credit: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI)





Now what makes the black hole that was discovered to be part of J05215658 so interesting? It isn't because it's the smallest known black hole to date, or because it's in a binary pair. It's important because it is very possible that it is a naked black hole and naked black holes are difficult to find, to say the least. A naked black hole isn't like what you see in the movie Interstellar or the recent photo of the accreting black hole, M87.





The image of the Super Massive black hole in the center of M87. This is NOT what a naked black hole looks like. A naked black hole has no accretion disk, is not interacting with it's companion, or literally doing anything that would cause light emission. Naked black holes are so boring that they become exciting.

Credits: Event Horizon Telescope collaboration et al.



Now, the only reason we were able to see M87 in the first place is because it has an 'accretion disk'. An accretion disk is generally when a bunch of gas and dust is spiraling into a black hole, the spiraling due to the friction between particles. All this friction causes the stuff spiraling in to heat up, causing an enormous amount of light to be emitted. Due to the enormous gravitational forces a black hole produces, the friction caused by its gravity within an accretion disk can paradoxically lead to black holes outshining nearly every other source within a galaxy.



This isn't the case with a naked black hole. A naked black hole is literally one of the more boring things you could take a picture of. It's not emitting anything, it doesn't have an accretion disk, it doesn't interact with any other stars. Below is an accurate artistic simulation of what a naked black hole would look like in an empty universe





This is an incredibly detailed, hand crafted, and accurate artistic depiction of what a naked black hole looks like in an empty universe. What is that you say, all you see is a bunch of blackness? Well buddy, I'll have you know, that this took me a whole thirty seconds in Microsoft Word to make, incredibly precise use of screen capture technology, and nimble fingers on my glass, capacitive trackpad. If you can't appreciate fine art I just don't know what to tell you >:(.