View source for Mount Laguna Observatory

{{Infobox observatory
 | name            = Mount Laguna Observatory
 | image           = [[File:MLO-1-npaci.jpg|292px]]
 | caption         = Dome of the Smith (24") Telescope at MLO
 | logo            = {{Infobox mapframe|wikidata=yes|height=292|width=292|zoom=16|marker=monument|coord={{Coord|32.8424|N|116.4280|W}}}}
 | logo_caption    = Dynamic map of SDSU Astronomy campus
 | map_type        = USA California San Diego County
 | map_size        = 292px
 | map_caption     = Observatory location within [[San Diego County, California|San Diego County]]
 | organization    = [[San Diego State University]]
 | code            = 
 | location        = [[Mount Laguna, California]]
 | coords          = {{Coord|32.8424|N|116.4280|W|type:landmark|display=inline,title}}
 | altitude        = {{Convert|1859|m|ft|sp=us}}
 | weather         = 
 | established     = {{Start date and age|1968|p=yes}}
 | telescope1_name = Illinois Telescope
 | telescope1_type = {{Convert|1.1|m|in|abbr=on|sp=us}}&nbsp;reflector
 | telescope2_name = Smith Telescope
 | telescope2_type = {{Convert|0.6|m|in|abbr=on|sp=us}}&nbsp;reflector
 | telescope3_name = Buller Visitors' Telescope
 | telescope3_type = {{Convert|0.5|m|in|abbr=on|sp=us}}&nbsp;reflector
 | telescope4_name = Claud Telescope
 | telescope4_type = {{Convert|1.25|m|in|abbr=on|sp=us}}&nbsp;reflector
 | telescope5_name = EvryScope
 | telescope5_type = Multiple Aperture Survey
 | website         = {{URL|https://astronomy.sdsu.edu/mount-laguna-observatory-facilities/|MLO Facilities}}
}}
'''Mount Laguna Observatory''' ('''MLO''') is an [[astronomy|astronomical]] [[observatory]] owned and operated by [[San Diego State University]] (SDSU).<ref>{{Cite web|url=https://www.sdsu.edu/index.aspx|title=Home|website=[[San Diego State University]]}}</ref> MLO is located approximately {{Convert|75|km|mi|sp=us}} east of downtown [[San Diego]], California, on the eastern edge of [[Cleveland National Forest]], in the [[Laguna Mountains]] on the SDSU Astronomy Campus near the hamlet of [[Mount Laguna, California|Mount Laguna]]. 

MLO was dedicated on June 19, 1968, seven years after SDSU's Department of Astronomy<ref>{{Cite web|url=https://astronomy.sdsu.edu/|title=Department of Astronomy|date=February 2, 2023}}</ref> became an independent academic department of SDSU's College of Sciences. The dedication took place during the 1968 summer meeting of the [[Astronomical Society of the Pacific]].<ref name="1969SMTH" /> The telescope was operated in partnership with the [[University of Illinois at Urbana-Champaign]] (UIUC) until 2000. Currently, SDSU is working with the [[University of Kansas]] (KU) and the [[University of North Carolina at Chapel Hill]] on various projects. 

== Telescopes ==
* The {{Convert|1.06|m|in|abbr=on}} MLO 40-inch telescope is a [[Cassegrain reflector]] built by Astro Mechanics in 1966. It was originally fitted with a {{Convert|1.02|m|in|abbr=on}} [[primary mirror]] which has since been replaced. It is known informally as the Illinois telescope because it was located at UIUC's [[University of Illinois Observatory#Modern Department|Prairie Observatory]] until 1981.<ref name="40IN" />
* The {{Convert|0.6|m|in|abbr=on}} Clifford Smith 24-inch telescope is a Cassegrain reflector. It was built by the SDSU Department of Astronomy and used at the main campus from 1961 to 1966. In 1971, it was installed at MLO after modifications.<ref name="24IN" /><ref name="24IN-TOUR" />
* The {{Convert|0.52|m|in|abbr=on}} Reginald Buller 21-inch Visitors' telescope was built in 1950 by J.W. Fecker, Inc. It was donated to SDSU by Reginald Buller and dedicated at MLO in 1988. It is used primarily by students for direct viewing, and for outreach.<ref name="21IN" />
* The EvryScope is a multiple aperture (24x) {{Convert|.062|m|in|abbr=on}} survey telescope taking approximately {{#formatnum:8000}} square degree fields every two minutes. It is a collaboration between SDSU and [[University of North Carolina at Chapel Hill|UNC]].<ref>{{Cite web|url=https://evryscope.astro.unc.edu/|title=50 GPix, 20% of the sky every second|date=2022-12-06|website=50 GPix, 20% of the sky every second|df=mdy-all}}</ref>

=== Future telescopes ===
* The {{Convert|1.25|m|in|abbr=on}} 50-inch Phillips Claud telescope.<ref>{{Cite magazine|author=<!--Staff writer(s); no by-line.-->|date=2014-11-26|title=New Eye in the Sky|url=https://www.sandiegometro.com/2014/11/daily-business-report-nov-26-2014/|magazine=SD Metro|access-date=2023-01-03|df=mdy-all}}</ref> Originally planned in 2009, installation of the telescope began in late 2013.<ref>{{Cite news|last=Quintero|first=Ashley|date=2015-02-23|title=SDSU telescope to yield new insight|url=https://thedailyaztec.com/63698/news/sdsu-telescope-to-yield-new-insight/|work=[[The Daily Aztec]]|institution=[[San Diego State University]]|access-date=2023-01-03|df=mdy-all}}</ref> {{As of|November 2016}}, the telescope installation had not been completed.<ref>{{Cite news|last=Yribarren|first=Carly|date=2016-11-22|title=Shooting for the Stars|url=https://newscenter.sdsu.edu/sdsu_newscenter/news_story.aspx?sid=76454|work=[[The Daily Aztec]]|institution=[[San Diego State University]]|access-date=2023-01-03|df=mdy-all}}</ref>

=== Former telescopes ===
* A {{Convert|0.4|m|in|abbr=on}} telescope built by [[Boller and Chivens]] was the first telescope at the observatory, and was replaced by the Claud telescope.<ref name="50IN" />
* A {{Convert|0.4|m|in|abbr=on}} telescope built by Nishimura and used by visitors was moved to the UCSD campus in 1988. It was replaced by the Buller telescope.<ref name="1989RPRT" />
* The {{Convert|1.0|m|in|abbr=on}} Ultra-Light Technology for Research in Astronomy (ULTRA) telescope was a test bed for lightweight [[Carbon fibers|carbon fiber]] mirrors. It was located in the 0.4&nbsp;m Boller and Chivens building from 2006–2008.  Before it was installed, the original dome was replaced with a larger one, and the mount upgraded.<ref name="50IN" /> The project was collaboration of SDSU, KU, [[Dartmouth College]], and Composite Mirror Applications, Inc. (CMA) of [[Tucson, Arizona]].<ref name="KU-MLO" />

== See also ==
* [[Palomar Observatory]]
* [[List of astronomical observatories]]

== References ==
{{Reflist|refs=
<ref name=1969SMTH>{{Cite journal |doi=10.1086/128742 |title=The Mount Laguna Observatory of San Diego College |date=1969 |last1=Smith |first1=C. E. |last2=Nelson |first2=Burt |journal=Publications of the Astronomical Society of the Pacific |volume=81 |issue=478 |pages=74 |bibcode = 1969PASP...81...74S |jstor=40674695|doi-access=free }}</ref>

<ref name=40IN>{{Cite web |title=MLO 40-inch Telescope |url=http://mintaka.sdsu.edu/MLO/FACILITIES/40_in_scope.html |publisher=San Diego State University Department of Astronomy |access-date=2010-01-11 |url-status=dead |archive-url=https://web.archive.org/web/20100625174949/http://mintaka.sdsu.edu/MLO/FACILITIES/40_in_scope.html |archive-date=2010-06-25 }}</ref>

<ref name=24IN>{{Cite web |title=Smith 24-inch Telescope |url=http://mintaka.sdsu.edu/MLO/FACILITIES/24_in_scope.html |publisher=San Diego State University Department of Astronomy |access-date=2010-01-11 |url-status=dead |archive-url=https://web.archive.org/web/20100625175738/http://mintaka.sdsu.edu/MLO/FACILITIES/24_in_scope.html |archive-date=2010-06-25 }}</ref>

<ref name=24IN-TOUR>{{Cite web |title=The Clifford Smith 24-inch Telescope |url=http://mintaka.sdsu.edu/tour/24_inside.html |publisher=San Diego State University Department of Astronomy |access-date=2010-01-11}}</ref>

<ref name=21IN>{{Cite web |title=Buller 21-inch Telescope |url=http://mintaka.sdsu.edu/MLO/FACILITIES/21_in_scope.html |publisher=San Diego State University Department of Astronomy |access-date=2010-01-11 |url-status=dead |archive-url=https://web.archive.org/web/20100625180052/http://mintaka.sdsu.edu/MLO/FACILITIES/21_in_scope.html |archive-date=2010-06-25 }}</ref>

<ref name=50IN>{{Cite web |title=The 50-inch Phillips Claud Telescope |url=http://mintaka.sdsu.edu/facilities/50_in_scope.html |publisher=San Diego State University Department of Astronomy |access-date=2010-01-11 |url-status=dead |archive-url=https://web.archive.org/web/20100630052829/http://mintaka.sdsu.edu/facilities/50_in_scope.html |archive-date=2010-06-30 }}</ref>

<!-- <ref name=50IN2>{{Cite web |title=Daily Aztec Article on Claud Telescope |date=8 July 2013 |url=http://www.thedailyaztec.com/2013/07/telescope-sdsu-phillipsclaud/ |publisher=SDSU Daily Aztec |access-date=2013-07-13}}</ref> -->

<ref name=1989RPRT>{{Cite journal |bibcode=1989BAAS...21..565. |title=Annual Reports of Astronomical Observatories and Departments: San Diego State University, Astronomy Department and Mount Laguna Observatory |volume=21 |date=1989 |pages=565 |journal=Bulletin of the American Astronomical Society }}</ref>

<ref name=KU-MLO>{{Cite web |title=MLO Telescope Project - Physics and Astronomy |url=http://www.physics.ku.edu/~physics/astronomy/mlotelescope.shtml |publisher=University of Kansas Department of Physics & Astronomy |access-date=2012-01-11 |url-status=dead |archive-url=https://web.archive.org/web/20120102181924/http://www.physics.ku.edu/~physics/astronomy/mlotelescope.shtml |archive-date=2012-01-02 }}</ref>
}}

== External links ==
* [https://astronomy.sdsu.edu Department of Astronomy] at San Diego State University
* [https://mlo.sdsu.edu Current conditions at MLO] Note: May be using a Self-Signed SSL certificate
* [https://cleardarksky.com/c/MtLagOBCAkey.html Mount Laguna Observatory Clear Sky Clock] Forecasts of observing conditions.
* [http://evryscope.astro.unc.edu/ EvryScope Project at UNC]

{{San Diego State University}}
{{California State University}}
{{University of Kansas}}
{{University of North Carolina at Chapel Hill}}
{{University of Illinois at Urbana-Champaign campus}}
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[[Category:Astronomical observatories in California]]
[[Category:Astronomy institutes and departments]]
[[Category:Buildings and structures in San Diego County, California]]
[[Category:California State University]]
[[Category:San Diego State University buildings and structures]]
[[Category:University of Illinois Urbana-Champaign]]
[[Category:University of Kansas]]
[[Category:University of North Carolina at Chapel Hill buildings]]
[[Category:1968 establishments in California]]
[[Category:Cleveland National Forest]]