There Are Infinite Rings Of Light Around Black Holes. Here's How We Could See Them

[Thoth101]

VictorMedvil you will like this article because it has your avatar in the article. :lol:

 

https://www.sciencealert.com/sending-telescopes-to-space-could-reveal-the-infinite-rings-around-a-black-hole

 

In that historic first image of M87* (above), we can see the accretion disc - that's the glowing orange-gold part. The black part in the center is the black hole's shadow. We can't actually see the photon sphere, since the ring is very fine, and the resolution isn't high enough to make it out, but it should sit around the edge of the black hole's shadow.

If we could see it, that ring would tell us very important things about the black hole. The size of the ring can tell us the mass, size and rotation of the black hole. We can determine these from the accretion disc, but the photon ring would allow us to constrain the data further, for a more precise measurement.

 

 

"Each subring consists of photons lensed toward the observer screen after having been collected by the photon shell from anywhere in the Universe," the researchers wrote in their paper.

"Hence, in an idealized setting with no absorption, each subring contains a separate, exponentially demagnified image of the entire Universe, with each subsequent subring capturing the visible Universe at an earlier time.

"Together, the set of subrings are akin to the frames of a movie, capturing the history of the visible Universe as seen from the black hole."