MMT Observatory
Encyclopedia
The MMT Observatory is an astronomical observatory on the site of Fred Lawrence Whipple Observatory
(IAU observatory code 696). The Whipple observatory complex is located on Mount Hopkins
, Arizona
, USA (55 km south of Tucson
) in the Santa Rita Mountains
. The observatory is run by the University of Arizona
and the Smithsonian Institution
, and has a visitor center in nearby Amado, Arizona
.
The MMTO is the home of the MMT (formerly Multiple Mirror Telescope), which currently has a primary mirror
6.5 m in diameter
. The name originally comes from the fact that the light gathering for the telescope
was done by six smaller mirrors before the current primary mirror was installed. The current mirror is notable because it is of a special lightweight honeycomb design made by the University of Arizona
's Steward Observatory
Mirror Laboratory.
The MMT is also notable because of its interesting building, which does not look in the least like the typical observatory dome. The building's unique shape is in order to completely roll back the walls and roof around the telescope, thus allowing it to cool down very quickly in order to improve the seeing
.
, a co-rotating building and an altitude-azimuth mount.
With the exception of the Bolshoi Teleskop Azimutalnyi (BTA-6)
and William Herschel's 40-foot telescope
, major optical telescopes prior to the MMT used equatorial mount
s. The MMT heralded a change in telescope design; all major optical telescopes since the MMT have been built with alt-azimuth mounts. Several technologies pioneered at the MMT contributed to the success of the subsequent generation of large telescopes. These included: high dynamic-range servos for the alt-azimuth mount; highly accurate pointing that eliminated the need for sky charts; co-alignment and co-phasing of multiple telescopes; improvements to optical performance by attention to the
thermal environment of the facility; contributions to vacuum coatings deposition, optics cleaning, and maintenance; and early experiments in co-phased adaptive optics.
, of the University of Arizona, who cast mirrors with a honeycomb structure in the interior of a rotating oven. This made it possible to replace the six mirrors with a single 6.5-meter one. The original building and part of the structure could be reused. The new mirror was cast and polished in the Steward Observatory Mirror Laboratory at the University of Arizona. It was the first 6.5-meter mirror cast at SOML.
The new MMT was rededicated on 20 May 2000. http://cfa-www.harvard.edu/cfa/ep/almanac/0700.htm
In late 2002, a novel deformable
secondary mirror
was added to the telescope. http://uanews.org/node/7538 While other adaptive optics
designs do their corrections with additional mirrors, minimizing the number of warm surfaces in the light path produces better results in infrared
wavelengths. The MMT AO system contributed to the design of the Large Binocular Telescope
, which achieved record breaking Strehl ratio
s with its AO system in 2010.
From 2004 to 2010, approximately 8% of MMT observing time was made accessible to the entire astronomical community via the US National Science Foundation
's Telescope System Instrumentation Program (TSIP), administered by the National Optical Astronomy Observatory
(NOAO). http://www.noao.edu/system/tsip/summary.php
Fred Lawrence Whipple Observatory
The Fred Lawrence Whipple Observatory is an astronomical observatory owned and operated by the Smithsonian Astrophysical Observatory and is their largest field installation outside of their main site in Cambridge, MA...
(IAU observatory code 696). The Whipple observatory complex is located on Mount Hopkins
Mount Hopkins (Arizona)
Mount Hopkins is a mountain in Santa Cruz County, Arizona part of the Santa Rita Mountains range. Fred Lawrence Whipple Observatory is located on it. It is within the Coronado National Forest and was named after Gilbert Hopkins who was killed nearby in 1865 during the Battle of Fort Buchanan....
, Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, USA (55 km south of Tucson
Tucson, Arizona
Tucson is a city in and the county seat of Pima County, Arizona, United States. The city is located 118 miles southeast of Phoenix and 60 miles north of the U.S.-Mexico border. The 2010 United States Census puts the city's population at 520,116 with a metropolitan area population at 1,020,200...
) in the Santa Rita Mountains
Santa Rita Mountains
The Santa Rita Mountains, located about 65 km southeast of Tucson, Arizona, extend 42 km from north to south, then trending southeast. They merge again southeastwards into the Patagonia Mountains, trending northwest by southeast...
. The observatory is run by the University of Arizona
University of Arizona
The University of Arizona is a land-grant and space-grant public institution of higher education and research located in Tucson, Arizona, United States. The University of Arizona was the first university in the state of Arizona, founded in 1885...
and the Smithsonian Institution
Smithsonian Institution
The Smithsonian Institution is an educational and research institute and associated museum complex, administered and funded by the government of the United States and by funds from its endowment, contributions, and profits from its retail operations, concessions, licensing activities, and magazines...
, and has a visitor center in nearby Amado, Arizona
Amado, Arizona
Amado is a census-designated place in Santa Cruz County, Arizona, United States. The population was 275 at the 2000 census.-Geography:Amado is located at ....
.
The MMTO is the home of the MMT (formerly Multiple Mirror Telescope), which currently has a primary mirror
Primary mirror
A primary mirror is the principal light-gathering surface of a reflecting telescope.-Description:The primary mirror of a reflecting telescope is a spherical or parabolic shaped disks of polished reflective metal , or in later telescopes, glass or other material coated with a reflective layer...
6.5 m in diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
. The name originally comes from the fact that the light gathering for the telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
was done by six smaller mirrors before the current primary mirror was installed. The current mirror is notable because it is of a special lightweight honeycomb design made by the University of Arizona
University of Arizona
The University of Arizona is a land-grant and space-grant public institution of higher education and research located in Tucson, Arizona, United States. The University of Arizona was the first university in the state of Arizona, founded in 1885...
's Steward Observatory
Steward Observatory
The University of Arizona's Steward Observatorys main office is located on the University's campus and is closely tied to the Department of Astronomy. Established in 1916 by its first director, Andrew Ellicott Douglass, and a $60,000 bequest made by Lavinia Steward in memory of her late husband...
Mirror Laboratory.
The MMT is also notable because of its interesting building, which does not look in the least like the typical observatory dome. The building's unique shape is in order to completely roll back the walls and roof around the telescope, thus allowing it to cool down very quickly in order to improve the seeing
Astronomical seeing
Astronomical seeing refers to the blurring and twinkling of astronomical objects such as stars caused by turbulent mixing in the Earth's atmosphere varying the optical refractive index...
.
Multiple Mirror Telescope (1979-1998)
The MMT operated between 1979 and 1998 with 6 mirrors, each with a diameter of 1.8 meters, providing the equivalent gathering area of a 4.5-meter telescope, making it the third largest optical telescope in the world at the time of its dedication. It featured ambitious design innovations including its unusual optical design proposed by Aden MeinelAden Meinel
Aden B. Meinel was an American astronomer. He retired in 1993 as a Distinguished Scientist at the Jet Propulsion Laboratory. He also held the rank of Professor Emeritus at the University of Arizona College of Optical Sciences...
, a co-rotating building and an altitude-azimuth mount.
With the exception of the Bolshoi Teleskop Azimutalnyi (BTA-6)
BTA-6
The BTA-6 is a 6 m aperture optical telescope at the Special Astrophysical Observatory located in the Zelenchuksky District on the north side of the Caucasus Mountains in southern Russia...
and William Herschel's 40-foot telescope
40-foot telescope
William Herschel's 40-foot telescope, also known as the Great Forty-Foot telescope, was a reflecting telescope constructed between 1785 and 1789 at Observatory House in Slough, England. It used a 120 cm diameter primary mirror with a 12 m long focal length . It was the largest telescope in...
, major optical telescopes prior to the MMT used equatorial mount
Equatorial mount
An equatorial mount is a mount for instruments that follows the rotation of the sky by having one rotational axis parallel to the Earth's axis of rotation. This type of mount is used for astronomical telescopes and cameras...
s. The MMT heralded a change in telescope design; all major optical telescopes since the MMT have been built with alt-azimuth mounts. Several technologies pioneered at the MMT contributed to the success of the subsequent generation of large telescopes. These included: high dynamic-range servos for the alt-azimuth mount; highly accurate pointing that eliminated the need for sky charts; co-alignment and co-phasing of multiple telescopes; improvements to optical performance by attention to the
thermal environment of the facility; contributions to vacuum coatings deposition, optics cleaning, and maintenance; and early experiments in co-phased adaptive optics.
MMT (1998-present)
One of the reasons for its original multiple mirror design was the difficulty of casting large mirrors. One solution to this problem was found by Roger Angel of Steward ObservatorySteward Observatory
The University of Arizona's Steward Observatorys main office is located on the University's campus and is closely tied to the Department of Astronomy. Established in 1916 by its first director, Andrew Ellicott Douglass, and a $60,000 bequest made by Lavinia Steward in memory of her late husband...
, of the University of Arizona, who cast mirrors with a honeycomb structure in the interior of a rotating oven. This made it possible to replace the six mirrors with a single 6.5-meter one. The original building and part of the structure could be reused. The new mirror was cast and polished in the Steward Observatory Mirror Laboratory at the University of Arizona. It was the first 6.5-meter mirror cast at SOML.
The new MMT was rededicated on 20 May 2000. http://cfa-www.harvard.edu/cfa/ep/almanac/0700.htm
In late 2002, a novel deformable
Deformable mirror
Deformable mirror represents the most convenient tool for wavefront control and correction of optical aberrations. Deformable mirrors are used in combination with wavefront sensors and real-time control systems in adaptive optics...
secondary mirror
Secondary mirror
A secondary mirror is the second deflecting or focusing mirror element in a reflecting telescope. Light gathered by the primary mirror is directed towards a focal point typically past the location of the secondary. Secondary mirrors in the form of an optically flat diagonal mirror are used to...
was added to the telescope. http://uanews.org/node/7538 While other adaptive optics
Adaptive optics
Adaptive optics is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, and in retinal imaging systems to reduce the...
designs do their corrections with additional mirrors, minimizing the number of warm surfaces in the light path produces better results in infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
wavelengths. The MMT AO system contributed to the design of the Large Binocular Telescope
Large Binocular Telescope
Large Binocular Telescope is an optical telescope for astronomy located on Mount Graham in the Pinaleno Mountains of southeastern Arizona, and is a part of the Mount Graham International Observatory...
, which achieved record breaking Strehl ratio
Strehl ratio
The Strehl ratio, named after the German physicist and mathematician Karl Strehl , is a measure for the optical quality of telescopes and other imaging instruments...
s with its AO system in 2010.
From 2004 to 2010, approximately 8% of MMT observing time was made accessible to the entire astronomical community via the US National Science Foundation
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
's Telescope System Instrumentation Program (TSIP), administered by the National Optical Astronomy Observatory
National Optical Astronomy Observatory
The National Optical Astronomy Observatory is the United States national observatory for ground based nighttime ultraviolet-optical-infrared astronomy. The National Science Foundation funds NOAO to provide forefront astronomical research facilities for US astronomers...
(NOAO). http://www.noao.edu/system/tsip/summary.php