We Have Ploonets. We Have Moonmoons. Now Hold Onto Your Hats For... Blanets
It's easy to think of black holes as voracious destruction machines, slurping up everything in their immediate vicinity. But that's not always the case. The environments around active supermassive black holes are complex, and last year, a team of astronomers showed that there's a safe zone around each supermassive black hole in which thousands of planets could be orbiting.
Now, the team led by Keiichi Wada of Kagoshima University in Japan has given a new name to these black hole planets - "blanets", which is just delightful - and worked out how these blanets might form from the grains of dust swirling around the black hole.
"Here, we investigate the dust coagulation processes and physical conditions of the blanet formation," they wrote in a paper currently submitted to The Astrophysical Journal for peer review, and uploaded to the pre-print service arXiv.
"Our results suggest that blanets could be formed around relatively low-luminosity active galactic nuclei during their lifetime."
We know that stars can be captured in orbit around supermassive black holes - astronomers have been observing the complex dance of stars around Sagittarius A*, the supermassive black hole at the heart of the Milky Way, for decades.
It's also been hypothesised that exoplanets - both orbiting those captured stars, or rogue - can be captured by black holes, too.
But Wada's team proposes a new class of exoplanets, those that form directly around active supermassive black holes at the hearts of galaxies. Such an active black hole is surrounded by an accretion disc, a huge torus of dust and gas swirling around, its inner rim feeding into the black hole. ...
