zone of avoidance

The zone of avoidance is a band around the sky in which very few extragalactic objects can be seen at visible wavelengths because of the heavy absorption of light by dust in the plane of the Milky Way. The zone of avoidance is by no means regular, varying width from about 38° in the direction of the center of our Galaxy (in Sagittarius) to about 12°. Additionally, there are a number of galactic windows in the zone that are relatively free of obscuring material and therefore offer a clear view of the outside universe.