During this tracking, there were 12 significant time delays that could be candidates for unknown objects in space, based on the changes of these eight pulsars. Some of these candidates were relatively small, such as one that was about one-fifth the size of the sun.
Although the objects have been identified, it is still uncertain what exactly they are. There are several bodies in space that would make sense. They could potentially be runaway planets, dwarf stars, dark matter, or something else entirely.
“I’ve been warned not to call them planets, not to call them dark matter, just call them mass concentrations, because you can’t tell what they are just by looking at the radio. I can’t even guarantee that they’re dark. They could be brown dwarfs or some kind of white dwarf or something else.”