Only by using adaptive optics to produce very sharp images could we have found this companion. It is too faint and too close to its parent star to be seen otherwise.
If the halo had a normal, stellar population, we should have seen over 100 bright stars in our images. Much to our surprise, we only saw a handful of them.
This discovery implies that brown dwarf companions to average, sunlike stars exist at a separation comparable to the distance between the sun and the outer planets in our solar system.
This companion is probably too massive to have formed the way we believe that planets do, namely from a circumstellar disk of gas and dust when the star was young. This finding suggests that a diversity of processes act to populate the outer regions of other systems.
They're all excited to be here. Three girls and a boy.