The galaxies in the universe are not equally spaced. They are spread out in filaments with the most massive clusters at the intersection between these filaments. This is the so-called cosmic web, where strands of galaxies alternate with regions that host only a few of them.
The dipole repeller is one of the underdense regions of the universe, hence, a void. Future telescopes, either in radio or infrared might be powerful enough to catch a glimpse of the small dim galaxies that might inhabit this particular void and by doing so, we'll be able to refine our view of the cosmic web around the Milky Way.
"Observatories of the future will be better, but already we should have adequate facilities. It is just a problem of 'so many galaxies … so little time,'" co-author Brent Tully, told IFLScience.
"There are billions of galaxies in the observable universe. In terms of uniform coverage around the entire sky, we have only looked seriously at about 40,000," he added. "As the name implies, voids are rather empty, but not entirely so. The few galaxies within voids are usually small ones, which makes them all the more difficult to study. But not impossible – give us time."