Earth-Mass Planets Can Form around Brown Dwarfs

Brown dwarfs are objects that formed in the same way as stars and they have masses between 0.01 to 0.08 times the mass of the Sun. However, brown dwarfs are not massive enough to sustain hydrogen fusion in their cores. Just like young stars, young brown dwarfs can also be surrounded by dusty disks. From a sample of 29 well-characterized brown dwarfs and very low mass stars with masses ranging from 0.03 to 0.2 times the mass of the Sun, Daemgen et al. (2016) found that more than half of them have disk mass greater than one Jupiter-mass. The dust in the disks is estimated to have temperatures in the range between 7 to 15 K. Jupiter-mass disks around brown dwarfs have the potential to form Earth-mass planets. This shows that brown dwarfs can harbour sufficient material in their disks to form Earth-mass planets.

Reference:
Daemgen et al. (2016), "Brown dwarf disks with Herschel: Linking far-infrared and (sub)-mm fluxes", arXiv:1607.07458 [astro-ph.SR]