Each week, discover a new spectacular image obtained at CFHT . The distribution of matter in the Universe is highly structured.
Stars gather in galaxies.
Galaxies themselves are grouped in clusters. Clusters of galaxies are the largest structures in dynamical equilibrium in the Universe. They are composed of dark matter, hot gas and galaxies. Such systems act as very large cosmological laboratories. The Coma cluster is a prototypical rich cluster of galaxies, with over a thousand members known.