Mount Lemmon Observatory Telescopes and Instrumentation
Perched high in the Santa Catalina Mountains, the Mount Lemmon Optical Astronomy Observatory (LOAO) houses a diverse array of instruments designed for everything from planetary defense to public outreach. With eight operating telescopes, the facility blends high-precision research with accessibility, allowing both professional astronomers and amateur enthusiasts to peer into the depths of space.
Key Facts
- Eight active telescopes currently operate at the observatory.
- The Schulman Telescope is the world's largest telescope dedicated to remote internet control for astrophotographers.
- The facility contributes to the Catalina Sky Survey (CSS), focusing on the discovery and tracking of near-Earth objects.
- Instruments range in size from 0.5 meters to 1.52 meters in aperture.
- The observatory supports critical NASA missions, including TESS exoplanet characterization.
Primary Research and Survey Telescopes
The 1.52m Steward Observatory Telescope
The 1.52 m (60 in) Steward Observatory Telescope is a Cassegrain reflector—a design that uses a convex secondary mirror to fold the light path. This instrument is a cornerstone of the Mount Lemmon Survey (MLS), which operates as part of the Catalina Sky Survey (CSS). Originally built in the late 1960s and first installed at Catalina Station on Mount Bigelow, it moved to Mount Lemmon in 1972 and was re-housed in its current location in 1975. To improve performance, its original metal primary mirror was replaced in 1977 with a glass mirror made of Cer-Vit, a specialized glass-ceramic material known for its thermal stability. Notably, this telescope discovered the asteroid 2011 AG5, which reached a value of 1 on the Torino Scale.
The 1.52m UMN-MLOF Telescope
Operating since 1970, the 1.52 m (60 in) University of Minnesota Mount Lemmon Observing Facility (UMN-MLOF) telescope is a Dall-Kirkham design optimized for optical and near-infrared observations. Similar in design to the Steward telescope, it also underwent a mirror upgrade in 1974, replacing its original metal mirror with Cer-Vit. The University of California, San Diego (UCSD) served as an original operating partner alongside the University of Minnesota.
The 1.02m CSS Reflecting Telescope
The 1.02 m (40 in) Catalina Sky Survey (CSS) telescope utilizes an unusual Pressman-Camichel design. Its primary mission is to provide automated follow-up observations of newly discovered near-Earth objects. Originally located at Catalina Station, it was moved to Mount Lemmon in 1975, refurbished in 2008, and placed in a new dome in 2009 to integrate fully into CSS operations.
Specialized and Robotic Instruments
The 1.0m KASI Robotic Telescope
Installed in 2003, the 1.0 m (39 in) KASI telescope is the only instrument at the observatory operated by the Korea Astronomy and Space Science Institute (KASI), bringing an international dimension to the facility's research capabilities.
The 0.81m Schulman Telescope
The 0.81 m (32 in) Schulman Telescope is a Ritchey-Chrétien reflector—a design that eliminates coma for a wider field of view—built by RC Optical Systems and installed in September 2010. Operated by the Mount Lemmon SkyCenter, it holds the distinction of being Arizona's largest dedicated public observatory. It was specifically designed for remote internet control, making it the world's largest telescope dedicated to this purpose for amateur and professional astrophotographers.
The University of Louisville Manner Telescope
Also a Ritchey-Chrétien reflector built by RC Optical Systems, the 0.6 m (24 in) Manner Telescope is operated remotely. It specializes in high-precision photometry—the measurement of the intensity of an astronomical object's light—to confirm and characterize exoplanet candidates for NASA's TESS mission.
Additional Observatory Assets
The observatory maintains several other instruments to support its diverse mission:
- 0.7 m (28 in) Reflector: Installed in 1963 at Catalina Station and moved to Mount Lemmon in 1972.
- 0.6 m (24 in) Ritchey-Chrétien: Built by RC Optical Systems and operated by the Mount Lemmon SkyCenter.
- 0.5 m (20 in) John Jamieson Telescope: Donated to the University of Arizona in 1999 and dedicated in 2005, this instrument is optimized for near-infrared observing and operated by the Mount Lemmon SkyCenter.
Telescope Summary Table
| Telescope Name | Aperture | Design Type | Primary Use/Operator |
|---|---|---|---|
| Steward Observatory | 1.52 m | Cassegrain Reflector | Mount Lemmon Survey / CSS |
| UMN-MLOF | 1.52 m | Dall-Kirkham | Optical/Near-Infrared |
| CSS Telescope | 1.02 m | Pressman-Camichel | Near-Earth Object Follow-up |
| KASI | 1.0 m | Robotic | Korea Astronomy and Space Science Institute |
| Schulman | 0.81 m | Ritchey-Chrétien | Public/Remote Astrophotography |
| Manner | 0.6 m | Ritchey-Chrétien | NASA TESS / Photometry |
| John Jamieson | 0.5 m | Reflector | Near-Infrared / SkyCenter |
Frequently Asked Questions
What is the purpose of the Catalina Sky Survey (CSS)?
The CSS uses telescopes like the 1.52m Steward and the 1.02m reflecting telescope to discover and provide automated follow-up observations of near-Earth objects.
What makes the Schulman Telescope unique?
The Schulman Telescope is the world's largest telescope specifically designed for remote control over the internet, allowing astrophotographers worldwide to use it.
What is Cer-Vit and why was it used?
Cer-Vit is a glass-ceramic material used to replace original metal mirrors in the Steward and UMN-MLOF telescopes because the metal mirrors performed poorly.
How does the Manner Telescope support NASA?
The Manner Telescope performs high-precision photometry to confirm and characterize exoplanet candidates identified by NASA's TESS mission.
Which telescope discovered asteroid 2011 AG5?
The 1.52 m Steward Observatory Telescope discovered 2011 AG5, an asteroid that achieved a 1 on the Torino Scale.