Here's something kind of interesting:
A group of Japanese astrophysicists think that it's possible for planets to form not only in stellar accretion disks, but in black-hole accretion disks as well, including the super-massive black holes at the center of galaxies, which may play host to really huge planetary systems. Since the inner reaches of these accretion disks would be extremely energetic, it's hypothesized that these proposed planets might be distant, parsecs out from the black hole. And it's speculated that a single super-massive black hole might have lots of these planets.
They say: "Planetary systems are ubiquitous -- more than four thousand exoplanets have been discovered thus far. However, proplanetary disks around stars may not be the only site for planet formation in the universe. Here we propose a new site of "planet" formation: the circumnuclear disk around supermassive plack holes (SMBHs)."
But they also say...
"Observing planets around SMBHs should be challenging. The standard techniques to detect exoplanets around stars, i.e., Doppler spectroscopy, transit photometry, gravitational micro-lensing, or direct imaging are hopeless. Photometry by a hard X-ray interferometer in space might be a possible solution, but the occultation of the accretion disk by the "planets" would be hard to distinguish from the intrinsic time variability of AGNs. The other, indirect way is detecting spectral changes in the mm-wave length due to opacity variation associated with the dust growth as used in protoplanetary disk."
https://phys.org/news/2019-11-planets-bl...zarre.html
The abstract
https://arxiv.org/abs/1909.06748
The paper:
https://arxiv.org/pdf/1909.06748.pdf
Listen up, Science Fiction writers! Imagine an alien civilization with THAT rising in the sky every morning, bathing your alien skin and your beautiful tentacles with the healthy warmth of hard radiation.
A group of Japanese astrophysicists think that it's possible for planets to form not only in stellar accretion disks, but in black-hole accretion disks as well, including the super-massive black holes at the center of galaxies, which may play host to really huge planetary systems. Since the inner reaches of these accretion disks would be extremely energetic, it's hypothesized that these proposed planets might be distant, parsecs out from the black hole. And it's speculated that a single super-massive black hole might have lots of these planets.
They say: "Planetary systems are ubiquitous -- more than four thousand exoplanets have been discovered thus far. However, proplanetary disks around stars may not be the only site for planet formation in the universe. Here we propose a new site of "planet" formation: the circumnuclear disk around supermassive plack holes (SMBHs)."
But they also say...
"Observing planets around SMBHs should be challenging. The standard techniques to detect exoplanets around stars, i.e., Doppler spectroscopy, transit photometry, gravitational micro-lensing, or direct imaging are hopeless. Photometry by a hard X-ray interferometer in space might be a possible solution, but the occultation of the accretion disk by the "planets" would be hard to distinguish from the intrinsic time variability of AGNs. The other, indirect way is detecting spectral changes in the mm-wave length due to opacity variation associated with the dust growth as used in protoplanetary disk."
https://phys.org/news/2019-11-planets-bl...zarre.html
The abstract
https://arxiv.org/abs/1909.06748
The paper:
https://arxiv.org/pdf/1909.06748.pdf
Listen up, Science Fiction writers! Imagine an alien civilization with THAT rising in the sky every morning, bathing your alien skin and your beautiful tentacles with the healthy warmth of hard radiation.