I'm a space/astronomy buff, so I looked it up online. Brown dwarfs are pretty unlikely to host even one planet in the habitable zone, because the HZ for brown dwarfs is narrow and extremely close to the star, likely causing extreme tidal heating. (Basically, what the Moon does to Earth except on a much greater scale).
There's also the problem that brown dwarves cool as they age, meaning the HZ would move inwards and cause any habitable worlds to freeze solid. They also emit extreme amounts of UV radiation that would sterilize any planets as they age. As a result, planets like Venus are likelier to be found around brown dwarves than Earthlike planets.
