Astro Glossary

Boötes, the Herdsman

Brown Dwarf

A “failed” star, which is more massive than a planet but not massive enough to ignite nuclear fusion reactions at its core and shine as a true star.

Bubbles, Sheets and Voids

Superclusters of galaxies are arranged in structures that look like sheets or walls, surrounded by voids and filaments in the large-scale structure of the universe. Together, walls, voids, and filaments cause the large-scale structure of the universe to resemble foam bubbles. Sometimes walls, such as one dubbed the Great Wall, are the result of the intersection of several filaments.