Two thirds of all stars are thought to be part of binary, or more, systems, but I don't think it is known how frequently one is ejected, becoming rogue.
Originally Posted by Gamefreak89
My suspicion is there are many planets, pieces of, and failed stars out there floating around. As I understand it, supernovae could certainly eject some planets and companion stars from their systems. It has even been hypothesized our own system suffered such an encounter, early in its history, which could stand to reason if a nearby supernova prompted the formation of our solar system.
And space is really not that empty. It's quite full of gas and dust, hence the shockwave seen in your link.
The bigger stuff we wouldn't see, unless it's emitting heat and moving fast.
Where the telescope ends, the microscope begins. Which of the two has the greater view?