Harvard College Observatory Harvard College Observatory The Harvard College Observatory (HCO) is an institution managing a complex of buildings and multiple instruments used for astronomical research by the Harvard University Department of Astronomy. It is located in Cambridge, Massachusetts, USA, and was founded in 1839. With the Smithsonian Astrophysical Observatory, it forms part of the Harvard–Smithsonian Center for Astrophysics. HCO houses a collection of approximately 500,000 astronomical plates taken between the mid-1880s and 1989 (with a gap from 1953–68). This 100-year coverage is a unique resource for studying temporal variations in the universe. The Digital Access to a Sky Century @ Harvard project
Harvard University nearly 80 individual libraries holding over 18 million volumes. According to the American Library Association, this makes it the largest academic library in the United States, and one of the largest in the world. Houghton Library, the Arthur and Elizabeth Schlesinger Library on the History of Women in America, and the Harvard University Archives consist principally of rare and unique materials. America's oldest collection of maps, gazetteers, and atlases both old and new is stored in Pusey Library and open to the public. The largest collection of East-Asian language material outside of East Asia is held in the Harvard-Yenching Library.