David Dunlap Observatory Catalogue
David Dunlap Observatory Catalogue, known as the DDO or A Catalogue of Dwarf Galaxies, is a catalogue of dwarf galaxies that was published in 1959 (and later expanded in 1966) by Sidney van den Bergh.
David Dunlap Observatory Catalogue, known as the DDO or A Catalogue of Dwarf Galaxies, is a catalogue of dwarf galaxies that was published in 1959 (and later expanded in 1966) by Sidney van den Bergh.