The nearest planet "that we can detect".. What says that planets can only form around stars? Yes, its most likely since those are some of the biggest gravity

The nearest planet "that we can detect".. What says that planets can only form around stars? Yes, its most likely since those are some of the biggest gravity sources, but if you have a failed star system, or accumulation of mater out in deep space, no reason it can't aggregate and form its own starless planet