Supermassive Black Holes Could Host Millions of Exoplanets

• New research suggests that accretion disks surrounding supermassive black holes (SMBH) may serve as breeding grounds for tens of millions of giant planets.
• These environments rely on strong magnetization to maintain disk stability and suppress turbulence, enabling dust coagulation.
• The study, published in The Astrophysical Journal, proposes that planetesimals can form through the same streaming instability mechanisms observed in standard protoplanetary disks.

Planet and Star Formation

• Planets form in the cooler outer regions of active galactic nucleus (AGN) disks where dust can condense.
• These objects can reach masses ranging from Earth-sized to super-Jupiter scales.
• Through "crossover mass," these bodies can continue to accumulate gas, potentially evolving into stellar-mass objects or even intermediate-mass black holes (IMBH).

Nature of Dust Planets

• Unlike traditional planets, these are composed entirely of accumulated dust rather than layered materials.
• Researchers hypothesize they are "degenerate lava drops" with magma oceans and outgassed atmospheres, heated by the radioactive decay of elements like 26Al and 60Fe.

Dynamical Implications

• The massive nature of these objects causes them to migrate inward toward the SMBH due to dynamical interactions.
• This process provides a theoretical pathway for the birth of intermediate-mass black holes in the vicinity of larger galactic nuclei.