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Built in 1914, Van Vleck Observatory belongs to Wesleyan University. It is named after John M. Van Vleck, former head of the Department of Mathematics and Astronomy at Wesleyan from 1853 until 1912. There are three telescopes on-site in addition to several portable telescopes, used for a variety of purposes from research and teaching to public outreach. The observatory's telescopes include a 20-inch Alvan Clark refractor telescope, installed in the observatory in 1922; a 24-inch Perkin Reflector, acquired in 1971; and a 2.4-meter radio telescope constructed by Wesleyan students in 2013.

  • Van Vleck Observatory
History of Van Vleck Observatory
Wesleyan University was founded in 1831, and astronomy was among the earliest subjects taught. Professor John Van Vleck belonged to the Department of Mathematics and Astronomy from 1853 until 1912, following in the footsteps of Augustus Smith, a professor of mathematics and astronomy who also served as President of Wesleyan from 1852 to 1857.

The university acquired telescopes during its first few decades, including a 6-inch refractor telescope purchased in 1836. Early observatories were not always very sophisticated, however. Wesleyan's first "observatory" constituted a simple shed. Its second one, built on Foss Hill in 1868, became known as Observatory Hall. Around this time, Van Vleck acquired a 12-inch refractor telescope from Alvan Clark Company to replace the 6-inch one.

In 1903, Van Vleck's brother Joseph Van Vleck and other family members began collecting funds to build a new observatory. They reached their goal, and construction began on the new observatory in 1914, two years after the death of Prof. John Van Vleck.

Frederick Slocum was appointed Professor of Astronomy and Director of the Observatory, which opened in 1915 and was dedicated the next year. A 20-inch Alvan Clark refractor telescope arrived soon afterward in 1922. Slocum retained his position as observatory director from 1914 until 1944. 

Over the decades, Van Vleck Observatory has continued to serve the needs of Wesleyan students and facilitate research. The observatory has acquired new and more powerful telescopes and updated its technological capabilities (e.g. by automating the 24-inch Perkin Reflector). 

Telescopes housed at the Van Vleck Observatory
The observatory's telescopes include:
- 2.4-meter radio telescope: Built by Wesleyan students in 2013, this telescope continues to provide learning opportunities on campus. 
- 24-inch Perkin research telescope: This scope was built by Boller and Chivens (of Perkin-Elmer Corporation) in 1966 for Richard Perkin, whose family donated it to Wesleyan in 1971. It's a large reflector telescope with its primary mirror measuring 24 inches in diameter and its focal length reaching 27 feet. The telescope has been upgraded and automated since its donation. It is used for research and teaching at the university.
- 20-inch Alvan Clark refractor telescope: This telescope is considerably older than the previous two on this list. It was intended to be placed in the Van Vleck Observatory upon the building's dedication in 1916, but WWI prevented the timely import of glass pieces that had been ordered from Germany for the telescope's lenses. The glass did eventually arrive, and the telescope joined the observatory in 1922. 
- 16-inch Meade LX200GPS Schmidt-Cassegrain: This telescope provides learning opportunities to Wesleyan students.
- 10-inch portable Meade Schmidt-Cassegrain: Donated by Catherine Fiducia, this portable but powerful telescope joined the observatory in 1995. It is often brought to public observation events in and around Middletown.

Understanding telescopes
There are multiple broad categories of telescopes. Broadly speaking, the three main categories are: reflector, refractor, and catadioptric. Naturally, there is substantial variation among telescopes in each category, but some general characteristics hold true.

Refractor telescopes: Refractors were the first kind of telescope invented. Using a glass lens to collect light, they produce sharp images of relatively bright celestial objects and are excellent for lunar and planetary observation. The 20-inch Alvan Clark is an example of a refractor telescope.

Reflector telescopes: Reflectors use mirrors (instead of lenses) to focus light. Generally speaking, they are ideal for viewing dim and deep-space celestial bodies: galaxies, nebulae, star clusters. The 24-inch Perkin telescope is an example of a reflector. The 24-inch measurement refers to its aperture, the size of its primary mirror. The larger the aperture, the more light a telescope can collect, and the more powerful the telescope is. 

Catadioptric (compound) telescopes: These compound telescopes use both mirrors and lenses to produce images. 

"History." Wesleyan University Astronomy Department. Accessed January 13, 2019. 

"Research and Teaching Telescopes." Wesleyan University Astronomy Department. Accessed January 13, 2019.

"Van Vleck Observatory (1916)." Historic Buildings of Connecticut. July 06, 2018. Accessed January 13, 2019. 

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