Information: - The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution headquartered in Cambridge, Massachusetts, where it is joined with the Harvard College Observatory (HCO) to form the HarvardSmithsonian Center for Astrophysics (CfA). - 1252 Celestia , provisional designation 1933 DG , is a stony main - belt asteroid discovered on February 19 , 1933 , by American astronomer Fred Whipple at Oak Ridge Observatory operated by the Harvard - Smithsonian Center for Astrophysics at Massachusetts , United States . The S - type asteroid measures about 17 kilometers in diameter , rotates once every 10.6 hours and is heavily tilted towards the ecliptic by almost 34 degrees . It was named after the mother of the discoverer , Celestia MacFarland Whipple . - The Oak Ridge Observatory, also known as the George R. Agassiz Station, is located at 42 Pinnacle Road, Harvard, Massachusetts. It was operated by the Harvard-Smithsonian Center for Astrophysics as a facility of the Smithsonian Astrophysical Observatory (SAO) until August 19, 2005. Given the information above, choose from the list below the object entity that exhibits the relation 'site of astronomical discovery' with the subject '1252 celestia'. Choices: - harvard college observatory - oak ridge observatory
The answer to this question is:
harvard college observatory