Scientists made the discovery first by pinpointing their target through infrared images from the Canada-France-Hawaii Telescope, and later using the Very Large Telescope to deduce that the object was both too small to be a star as well as hot and young enough (752F and under 120 million years old) to fit the behavior of a planet orphaned early into its existence.
ENGADGET: University of Montreal detects an orbitless planet, shows that stars don't have an iron grip (video)