Sproul Observatory was an

astronomical Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include ...

observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Th ...

owned and operated by

Swarthmore College Swarthmore College ( , ) is a Private college, private Liberal arts colleges in the United States, liberal arts college in Swarthmore, Pennsylvania, United States. Founded in 1864, with its first classes held in 1869, Swarthmore is one of the e ...

. It was located in Swarthmore,

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, and named after

William Cameron Sproul William Cameron Sproul (September 16, 1870 – March 21, 1928) was an American politician from Pennsylvania who served as a Republican member of the Pennsylvania State Senate from 1897 to 1919 and as the 27th governor of Pennsylvania from 1919 t ...

, the 27th Governor of Pennsylvania, who graduated from Swarthmore in 1891. The 24" telescope was moved from Sproul Observatory to

Bentonville, Arkansas Bentonville is a city in and the county seat of Benton County, Arkansas, United States. The city is centrally located in the county with Rogers, Arkansas, Rogers adjacent to the east. The city proper had a population of 54,164 at the 2020 Unite ...

in July 2017.

History

In 1907, William Cameron Sproul communicated to the Board of Managers of Swarthmore College his desire to donate funds for the purchase of equipment for an astronomical observatory. Sproul was a successful businessman who graduated from Swarthmore in 1891 and a trustee to the college. At the time of the gift, he was serving as Pennsylvania State Senator for the 9th District and went on to become the 27th Governor of Pennsylvania. The telescope was built in 1911 by the John A. Brashear Company in

Pittsburgh, Pennsylvania Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. It is the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania (after Philadelphia) and the List of Un ...

. When the telescope was installed at the observatory in 1913, it was the largest on the East Coast of the United States and one of the largest in the world. From 1986 to 2004, the computer science department was given office and lab space in the observatory building. In 2009, Swarthmore College added the Peter van de Kamp Observatory to the newly built Science Center. The new observatory contained a more technologically advanced 24" reflecting telescope and replaced the Sproul Observatory for education and public outreach purposes. In 2017, the telescope was dismantled and moved to the Eighth Street Market in

to be restored, upgraded and used for public outreach. It is now at the NWA Space and Science Center. The book collection of the Sproul Observatory was donated to an astronomy center in Magdalena, New Mexico. In 2017, Swarthmore unveiled plans to renovate Sproul Observatory which will transform the observatory into the James Hormel and Michael Nguyen Intercultural Center at Sproul Hall which will bring the Intercultural Center, Interfaith Center, Religious and Spiritual Life Center and the Office of International Student Services in one building.

Directors

# John A. Miller (1923–1938) # Peter van de Kamp (1937–1972) #

Wulff-Dieter Heintz Wulff-Dieter Heintz (3 June 1930 – 10 June 2006) was a German astronomer who worked the latter part of his career in the United States. He was Professor Emeritus of Astronomy at Swarthmore College. He specialised in the characterisation of bina ...

(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 A planetary system is a set of gravitationally bound non-stellar bodies in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consis ...

and discoveries based on

astrometry Astrometry is a branch of astronomy that involves precise measurements of the positions and movements of stars and other Astronomical object, celestial bodies. It provides the kinematics and physical origin of the Solar System and this galaxy, th ...

using the

photographic plates Photographic plates preceded photographic film, film as the primary medium for capturing images in photography. These plates, made of metal or Glass, glass and coated with a light-sensitive Photographic emulsion, emulsion, were integral to early ...

made with the

refractor telescope A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens (optics), lens as its objective (optics), objective to form an image (also referred to a dioptrics, dioptric telescope). The refracting telescope d ...

. These plates were found to have a

systematic error Observational error (or measurement error) is the difference between a measurement, measured value of a physical quantity, quantity and its unknown true value.Dodge, Y. (2003) ''The Oxford Dictionary of Statistical Terms'', OUP. Such errors are ...

that was misinterpreted as the effect of a

planetary system A planetary system is a set of gravity, gravitationally bound non-stellar Astronomical object, bodies in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although ...

on the parent star. This error was identified as early as 1973 and confirmed by the observatory in the 1980s.

References

External links

Sproul Observatory

Swarthmore College Bulletin, March 2001, pp 30–33, ''Barnard's Wobble''

{{Coord, 39.90308, -75.3553, type:landmark_source:GoogleMaps Satellite, display=title Astronomical observatories in Pennsylvania Swarthmore College Planetary systems 2017 disestablishments in Pennsylvania

History

Directors

Planetary discovery controversies

See also

References

External links