The Boötes Void (/boʊˈoʊtiːz/ boh-OH-teez) (colloquially referred to as the Great Nothing) is an approximately spherical region of space found in the vicinity of the constellation Boötes, containing only 60 galaxies instead of the 2,000 that should be expected from an area this large, hence its name. With a radius of 62 megaparsecs (nearly 330 million light-years across), it is one of the largest voids in the visible universe, and is referred to as a supervoid.

It was discovered in 1981 by Robert Kirshner as part of a survey of galactic redshifts. Its centre is located 700 million light-years from Earth, and at approximately right ascension 14 50 and declination 46°.

The Hercules Supercluster forms part of the near edge of the void.

Origins

There are no major apparent inconsistencies between the existence of the Boötes Void and the Lambda-CDM model of cosmological evolution. The Boötes Void is theorized to have formed from the merger of smaller voids, much like the way in which soap bubbles coalesce to form larger bubbles. This would account for the small number of galaxies that populate a roughly tube-shaped region running through the middle of the void.

Confusion with Barnard 68

The Boötes Void has been often associated with images of Barnard 68, a dark nebula that does not allow light to pass through; however, the images of Barnard 68 are much darker than those observed of the Boötes Void, as the nebula is much closer and there are fewer stars in front of it, as well as its being a physical mass that blocks light passing through.

See also

• List of largest voids
• Baryon acoustic oscillations