A team of astronomers at the Event Horizon Telescope (EHT) collaboration, which utilizes a global network of radio telescopes to scour the skies, has just snapped a brand new image of a black hole. The EHT’s image is the result of gathering polarized light coming from swirling plasma around the black hole, and offers a brand new view of the feasting beast. A view that makes it seem like the immense gravitational well is indeed the cosmic Eye of Sauron.
The EHT recently announced the new picture, which features the black hole at the center of the galaxy, M87. If that name sounds familiar, it’s because this is the same black hole astronomers ever directly imaged, back in 2019.
Since then, astronomers working at EHT have been keeping an eye on the supermassive object. Reporting on its characteristics, including its odd wobbliness. But this new image appears far crisper than anything before it. And also stringier. Almost as if you’re looking head-on at a spool of fiery yarn.
Unlike the light in other images of this black hole, this one consists of polarized light waves. That is, light waves who’s vibrating electric charges are occurring on a single plane. Unpolarized light waves, by comparison, have vibrating electric charges that move in a variety of directions. I.e. if light waves have a single direction of oscillation, they’re in a state of polarization.
Swirling plasma around the black hole—which is moving at 99% the speed of light—emits the polarized light. The plasma also generates electromagnetic fields, and depending on the strength of those fields, causes different polarized light emission patterns to emerge, as the former affects the latter. If the electromagnetic fields the plasma creates are weak, for example, they occur in a circular pattern; if they’re strong, they look like the spokes of a wheel.
This particular black hole has electromagnetic fields of medium strength, and, as a result, emits a swirling pattern of polarized light. In turn, the polarized light waves we collect here on Earth have a spiraling pattern, and, again, look like Sauron’s cosmic eye. Consisting of yarn.
Aside from the novel look at black holes, these types of pictures will help enlighten black holes as a whole. EHT collaboration member, Andrew Chael, even says in the collaboration’s press release that these images are “key to understanding how the magnetic field allows the black hole to ‘eat’ matter and launch powerful jets.” Although, sadly, we’ll probably never know if it can scour Middle-earth for hobbits.