right|thumb|259x259px|A map of the Boötes Void
The Boötes Void ( ) (colloquially referred to as the Great Nothing) is a roughly spherical region of space in the vicinity of the constellation Boötes. It contains just 60 galaxies, which is significantly fewer than the approximately 2,000 galaxies expected for an area of comparable size. With a radius of 62 megaparsecs (nearly 200 million light-years), it is one of the largest known voids in the visible universe, and is often referred to as a "supervoid".
It was discovered in 1981 by astronomer Robert Kirshner as part of a survey of galactic redshift to map the large-scale structure of the universe. Its center is located 700 million light-years from Earth, It is hypothesized that the Boötes Void formed through the coalescence of smaller voids. This process may explain the presence of a limited number of galaxies within a roughly cylindrical region extending through the center of the void.
See also
- Baryon acoustic oscillations
- Black hole
- Cosmos