From my latest at Sky & Telescope:
Recent radio observations support the idea that brown dwarfs form like full-fledged stars do.
Brown dwarfs, which bridge the gap between stars and planets, have been an exciting target for astronomers since their discovery in the mid-1990s. Since that time, we’ve observed and classified hundreds of these objects, but the details of how they form still remain an active area of research. The answer to a simple question, “Do brown dwarfs form in a method similar to stars, or do they form more like planets?” has eluded astronomers for decades.
– See more at: Sky & Telescope