  Astrophysicists distinguish between three different types of compact stars.
These are white dwarfs, neutron stars, and black holes. The former contain
matter in one of the densest forms found in the Universe. This feature,
together with the unprecedented progress in observational astronomy, makes such
stars superb astrophysical laboratories for a broad range of exciting physical
studies. This article studies the role of strangeness for compact star
phenomenology. Strangeness is carried by hyperons, mesons, H-dibaryons, and
strange quark matter, and may leave its mark in the masses, radii, cooling
behavior, surface composition and the spin evolution of compact stars.
