Mount Laguna Observatory

Dome of the Smith (24") Telescope at MLO
Alternative names	Mount Laguna Observatory 1m
Organization	San Diego State University
Observatory code	U83
Location	Mount Laguna, California
Coordinates	32°50′33″N 116°25′41″W / 32.8424°N 116.4280°W / 32.8424; -116.4280
Altitude	1,859 meters (6,099 ft)
Established	1968 (1968)
Website	MLO Facilities
Telescopes
Illinois Telescope 1.1 m reflector Smith Telescope 0.6 m reflector Buller Visitors' Telescope 0.5 m reflector Claud Telescope 1.25 m reflector EvryScope Multiple Aperture Survey
Location of Mount Laguna Observatory
Related media on Commons
[edit on Wikidata]

Mount Laguna Observatory (MLO) is an astronomical observatory owned and operated by San Diego State University (SDSU).^[1] The telescope was operated in partnership with the University of Illinois at Urbana-Champaign (UIUC) until 2000. MLO is located approximately 75 kilometers (47 mi) east of downtown San Diego, California (USA) on the eastern edge of the Cleveland National Forest in the Laguna Mountains on the SDSU Astronomy Campus near the hamlet of Mount Laguna. MLO was dedicated on June 19, 1968, seven years after SDSU's Department of Astronomy^[2] 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.^[3] Currently SDSU is working with University of Kansas (KU), and UNC Chapel Hill on various projects. MLO also engages with the public through a series of scientific outreach efforts such as the summer visitors program (SVP). SVP's take place on select dates throughout the summer months (May - August, starting typically on Memorial Day weekend) and include scientific demonstrations in the museum / gift shop, an introductory lecture on astronomy, and a stargazing session using a myriad of telescopes such as the 0.52 m (20 in) Reginald Buller 21-inch Visitors' Telescope. The SVP is predominantly run by graduate students within the SDSU Astronomy Master's program.

Telescopes

• The 1.06 m (42 in) MLO 40-inch Telescope is a Cassegrain reflector built by Astro Mechanics in 1966. It was originally fitted with a 1.02 m (40 in) primary mirror which has since been replaced. It is known informally as the Illinois telescope because it was located at UIUC's Prairie Observatory until 1981.^[4]
• The 0.6 m (24 in) 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.^[5][6]
• The 0.52 m (20 in) 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.^[7]
• The EvryScope is a Multiple aperture (24x) .062 m (2.4 in) survey telescope taking Appx. 8000 square degree fields every two minutes. It is a collaboration between SDSU and UNC.^[8]

Future telescopes

• The 1.25 m (49 in) 50-inch Phillips Claud Telescope.^[9] Originally planned in 2009, installation of the telescope began in late 2013.^[10] As of November 2016^[update], the telescope installation had not been completed.^[11]

Former telescopes

• A 0.4 m (16 in) telescope built by Boller and Chivens was the first telescope at the observatory, and was replaced by the Claud telescope.^[12]
• A 0.4 m (16 in) telescope built by Nishimura and used by visitors was moved to the UCSD campus in 1988. It was replaced by the Buller telescope.^[13]
• The 1.0 m (39 in) Ultra-Light Technology for Research in Astronomy (ULTRA) telescope was a test bed for lightweight carbon-fiber mirrors. It was located in the 0.4 m Boller and Chivens building from 2006 until 2008. Before it was installed, the original dome was replaced with a larger one, and the mount upgraded.^[12] The project was collaboration of SDSU, KU, Dartmouth College, and Composite Mirror Applications, Inc. (CMA) of Tucson, Arizona.^[14]