|Altitude||60 meters (200 feet)|
Sproul Observatory is an astronomical observatory owned and operated by Swarthmore College. It is located in Swarthmore, Pennsylvania, United States, and is named after William Cameron Sproul, the 27th Governor of Pennsylvania, who graduated from Swarthmore in 1891.
- John A. Miller 1923-1938
- Peter van de Kamp 1937-1972
- Wulff-Dieter Heintz 1973-1982
- Sarah L. Lippincott 1982-
Planetary discovery controversies
Under the direction of Peter van de Kamp this observatory made numerous claims of planetary systems and discoveries based on astrometry using the photographic plates made with the 24 in (61 cm) refractor telescope. These plates were found to have a systematic error that was misinterpreted as the effect of a planetary system on the parent star. This error was identified as early as 1973 and confirmed by the observatory in the 1980s.
- "Astronomy at Swarthmore College". Retrieved 2008-04-12.
- John L. Hershey (June 1973). "Astrometric analysis of the field of AC +65 6955 from plates taken with the Sproul 24-inch refractor". Astronomical Journal 78 (5): 421–425. Bibcode:1973AJ.....78..421H. doi:10.1086/111436.
- Lippincott, S. L. (1982). "A Mistake in the Wobble". Science News 122: 51. Bibcode:1982SciN..122...51L. doi:10.2307/3967230.
- Sproul Observatory
- Swarthmore College Bulletin, March 2001, pp 30-33, Barnard's Wobble
- The Cunningham Building: Swarthmore's Other Observatory