A few different effects mark the area, which astronomers have dubbed the "heliosheath depletion region" or a "magnetic highway." The number of charged particles from the Sun there is very low. Measurements of cosmic rays from other, non-Sun sources, are high. Together, the measurements suggest a new boundary region between the heliosphere—the bubble around the Sun, in which the Sun exerts its influence—and interstellar space. Astronomers had not previously guessed such a region existed.