# Custer Observatory > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Custer_Observatory > Markdown URL: https://mediated.wiki/source/Custer_Observatory.md > Source: https://en.wikipedia.org/wiki/Custer_Observatory > Source revision: 1343384340 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) **Custer Observatory** is an astronomical [observatory](/source/Observatory) located in [Southold, New York](/source/Southold_(CDP),_New_York). It is owned and operated by the Custer Institute. Facing Peconic Bay and Shelter Island, Custer's location is host to some of the darkest skies on [Long Island](/source/Long_Island) as a result of the comparatively lower levels of light pollution in the area.[1] ## History The Custer Institute is [Long Island](/source/Long_Island)'s oldest [public observatory](/source/Public_observatory), and was founded in 1927 by [Charles Wesley Elmer](/source/Charles_Elmer) (co-founder of the [Perkin-Elmer Optical Company](/source/PerkinElmer)) and fellow amateur astronomers. The name was adopted to honor the hospitality of Mrs. Elmer, the grand-niece of [General George Armstrong Custer](/source/General_George_Armstrong_Custer). In 1942, the Custer Institute was incorporated as a non-profit educational corporation in the [State of New York.](/source/New_York_(state)) In 1938, the group purchased the land the institute presently occupies. The initial construction of the observatory was completed in the spring of 1939. A 100-seat lecture hall was added in 1945. A three-story tower, library and observatory dome were built in 1947. A shed housing three sliding-roof observatories was built for the institute in 1954. ## Telescopes Over the years, Custer has acquired a large collection of telescopes of all sizes and descriptions. Most recently,[when?] Custer acquired a 10" refracting telescope. Custer's telescope is the largest of its type in the United States. This telescope is in the main observatory dome. Custer's 10” refracting telescope was manufactured in [England](/source/England). The telescope's dialyte lenses make it apochromatic, providing enhanced views of the [Solar System](/source/Solar_System) and deep space objects. The folded light path construction uses mirrors to reduce the telescope's size, allowing the long f/12 focal length telescope to fit in Custer's dome. The telescope is attached to a computer-controlled Fornax 152 equatorial mount, permitting easy aiming and object tracking. The entire assembly can be raised/lowered on the Pier-Tech pier to accommodate most users’ heights for comfortable viewing. Previously, the dome was home to a 25-inch (f/5) reflector. To bring the eyepiece of this telescope to a level that does not require observers to climb a high ladder, the optics on this telescope were modified by Justine Haupt, an engineer at [Brookhaven National Lab](/source/Brookhaven_National_Laboratory). ## Custer Library The Custer Library contains a number of astronomy and science books dating from the 19th century to the present. It also houses the institute's videotape and 35mm astronomical slide collections. It contains *[National Geographic](/source/National_Geographic_Magazine)*, *[Sky & Telescope](/source/Sky_%26_Telescope)*, *Astronomy*, and *[Scientific American](/source/Scientific_American)* magazines dating back numerous decades. Membership to the Custer Institute grants access to their library. ## Custer Exhibit Room The Custer Institute Exhibit Room contains the following in its collection: - Henry Fitz, early Custer member and famous telescope mirror maker's Grinding Table. (This table is similar to the one on display at the Smithsonian in Washington, DC.) - [James Short's](/source/James_Short_(mathematician)) circa 1750 [Gregorian telescope](/source/Gregorian_telescope) variation designed to read the separation of [binary stars](/source/Binary_star). One of only three known to exist. - Various 18th and 19th centuries vintage spectrometers and sextants, along with other astronomical devices. - The Custer Rock Collection including [geodes](/source/Geode) and numerous Fossilized Rocks. - The Custer Meteorite Collection, which includes a [Shergottite](/source/Mars_meteorite) from Mars. - Numerous astronomical, [sunspot](/source/Sunspot), and [aurora](/source/Aurora_(astronomy)) pictures taken by past and present members. - The Custer Civil War Bullet Collection ## See also - [List of observatories](/source/List_of_observatories) ## References 1. See the light pollution map [\[1\]](http://cleardarksky.com/lp/CstrInsNYlp.html?Mn=astronomical) on ClearSkyChart.com. Note that there is still quite a bit of light pollution compared to northern New York and other parts of the Northeast. 1. ["Custer Observatory Homepage"](http://www.custerobservatory.org/). *Custer Index | Web page designed by David van Popering*. Retrieved August 19, 2009. 1. ["Montauk Observatory Project"](http://www.montaukobservatory.com/). Retrieved August 19, 2007. ## External links - [Custer Observatory Website](http://www.custerobservatory.org/) - [Custer Institute Clear Sky Clock](http://cleardarksky.com/c/CstrInsNYkey.html?1) Forecasts of observing conditions. --- Adapted from the Wikipedia article [Custer Observatory](https://en.wikipedia.org/wiki/Custer_Observatory) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Custer_Observatory?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.