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Mount Laguna Observatory

Astronomical observatory

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Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionJul 15, 2026
Entity authorityQ5650505
Source-derived summary

Mount Laguna Observatory (MLO) is an astronomical observatory owned and operated by San Diego State University (SDSU). MLO is located approximately 75 kilometers (47 mi) 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.

MLO was dedicated on June 19, 1968, seven years after SDSU's Department of Astronomy 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. 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 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.

The 0.6 m (24 in) Clifford Smith 24-inch telescope is a Cassegrain reflector.

Editorial summary

Begin with the source’s own compact description: “Mount Laguna Observatory” is astronomical observatory. The dossier treats that line as a proposition to test through Mount, Laguna and Observatory, not as a finished interpretation.

Editorial reviewA concise reference frame for defining the subject, testing terminology and identifying the institution closest to the evidence. The current lead gives the account dated anchors—1968, 2000, 1966, 1981—that can be checked directly. The selected authority fields contribute no independent date. For this dossier, Mount, Laguna and Observatory is the immediate research focus.
Editorial analysis

Why this record matters

The phrase “astronomical observatory” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.

Evidence profile

Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Jul 15, 2026. The linked authority identifier is Q5650505. Authority coordinates are 32.842, -116.428. 1 of 2 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1968, 2000, 1966 and 1981.

Critical limits

The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.

How to read it

Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.

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  • Subject orientation
  • Search vocabulary
  • Locating named sources
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The closest primary source, responsible institution and strongest cited specialist reference.

Three-step research path

  1. Establish the record: confirm the title “Mount Laguna Observatory”, its source revision and the description used here.
  2. Expand the search: follow Mount Laguna Observatory primary sources, Mount Laguna Observatory archive and Mount research across catalogues and specialist indexes.
  3. Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.

Questions for further research

  1. Which source most directly establishes the central claim about “Mount Laguna Observatory”?
  2. Which institution is responsible for the underlying evidence?
  3. Which cited source is closest to the event, object or claim?
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Source & attribution

This entry incorporates text from Mount Laguna Observatory” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.