The Lowell Discovery Telescope (LDT), formerly the Discovery Channel Telescope (DCT), is a aperture telescope owned and operated by

Lowell Observatory Lowell Observatory is an astronomical observatory in Flagstaff, Arizona, United States. Lowell Observatory was established in 1894, placing it among the oldest observatories in the United States, and was designated a National Historic Landmark ...

. The LDT was built at a dark sky site in the

Coconino National Forest The Coconino National Forest is a 1.856-million acre (751,000 ha) United States National Forest located in northern Arizona in the vicinity of Flagstaff. Originally established in 1898 as the "San Francisco Mountains National Forest Reserve", th ...

near

Happy Jack, Arizona Happy Jack is an Unincorporated area, unincorporated community and campground located in the Mogollon Rim, Mogollon Rim Region of Coconino County, Arizona, Coconino County, Arizona, United States. The Lowell Discovery Telescope is located there. ...

. Happy Jack is located at an elevation of and is approximately south-south-east of Flagstaff. The project was initially a partnership between

Discovery Communications Discovery, Inc. was an American multinational mass media factual television conglomerate based in New York City. Established in 1985, the company operated a group of factual and lifestyle television brands, such as the namesake Discovery Chann ...

and Lowell Observatory. The research partnerships have been extended to include

Boston University Boston University (BU) is a private research university in Boston, Massachusetts. The university is nonsectarian, but has a historical affiliation with the United Methodist Church. It was founded in 1839 by Methodists with its original campu ...

The University of Maryland The University of Maryland, College Park (University of Maryland, UMD, or simply Maryland) is a public land-grant research university in College Park, Maryland. Founded in 1856, UMD is the flagship institution of the University System of Mar ...

, The University of Toledo, and

Northern Arizona University Northern Arizona University (NAU) is a public research university based in Flagstaff, Arizona. It was founded in 1899 as the final public university established in the Arizona Territory, 13 years before Arizona was admitted as the 48th state. ...

. The telescope cost $53 million. It significantly augments Lowell Observatory's observational capability and enables pioneering studies in a number of important research areas. With its 4-meter class primary mirror, the Lowell Discovery Telescope is the fifth largest telescope in the continental United States (). Final construction of the telescope was completed by February 2012 and first light images were taken in April 2012.

Telescope

The LDT was designed by Alan Dodson and uses a Ritchey–Chrétien design. The 6700-pound

primary mirror A primary mirror (or primary) is the principal light-gathering surface (the objective) of a reflecting telescope. Description The primary mirror of a reflecting telescope is a spherical or parabolic shaped disks of polished reflective metal ...

measures in diameter yet only about in thickness. This finely figured, thin meniscus mirror, held in shape by a 156-element active optics system, regularly delivers sub-arcsecond seeing. The mirror was ground and polished into its

hyperbolic Hyperbolic is an adjective describing something that resembles or pertains to a hyperbola (a curve), to hyperbole (an overstatement or exaggeration), or to hyperbolic geometry. The following phenomena are described as ''hyperbolic'' because they ...

shape at the Optical Engineering and Fabrication Facility of the

University of Arizona College of Optical Sciences The University of Arizona College of Optical Sciences, considered the largest institute for optics education in the United States, is dedicated to research and education in optics with an emphasis on optical engineering. The college offers more ...

(in

Tucson, Arizona , "(at the) base of the black ill , nicknames = "The Old Pueblo", "Optics Valley", "America's biggest small town" , image_map = , mapsize = 260px , map_caption = Interactive map ...

). The telescope is one of the most powerful in the world, thanks to a unique housing that can accommodate up to five instruments at the Ritchey-Chrétien focus. The LDT can switch between any of these instruments in about a minute, making it uniquely suited for time-domain programs as well as opportunity targets such as gamma ray bursts and supernovae.

Construction

Lowell Observatory and Discovery Communications formed a partnership to build the Discovery Channel Telescope in February 2003. A special-use permit for construction and operation of the telescope at the Happy Jack site was received from the

United States Forest Service The United States Forest Service (USFS) is an agency of the U.S. Department of Agriculture that administers the nation's 154 national forests and 20 national grasslands. The Forest Service manages of land. Major divisions of the agency inc ...

in November 2004 and improvement of an existing road to the site commenced immediately. The

blank was completed by Corning in late 2005. Construction of the , telescope enclosure and an auxiliary support building began in mid-September 2005. Final figuring and polishing of the mirror, which weighs about , was completed by the

University of Arizona The University of Arizona (Arizona, U of A, UArizona, or UA) is a public land-grant research university in Tucson, Arizona. Founded in 1885 by the 13th Arizona Territorial Legislature, it was the first university in the Arizona Territory. T ...

's College of Optical Sciences. This process took about three years. The mirror was delivered to the site in June 2010, subsequently aluminized, and mounted on the telescope in August 2011. The telescope saw first light in 2012 and it was fully operational that year. The telescopes mirror was only expected to be 4.2 m, but it turned out that a mirror could be used.

Research

According to Director Jeffrey Hall, the telescope's original intent was for the study of comets, exoplanets, star formation in the Milky Way and other outer solar system projects. Other research includes observing the

Kuiper belt The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...

, and exploring distant stars and galaxies. The telescope will make space exploration easier, more effective, and efficient for existing programs as well. Initial Project Leaders include Dr. Jeffrey Hall, Director, Lowell Observatory; Dr. Stephen Levine, Commissioning Scientist; Bill DeGroff, Project Manager; Dr. Edward Dunham, Instrument Manager; and Ralph Nye, Director of Technical Services.

P/2016 BA14 (PanSTARRS) is a near-Earth object and periodic comet of the Jupiter family, that was radar imaged at distance of 2.2 million miles (3.5 million km, or 9 lunar distances) during a flyby of Earth in 2016. This enabled the size of the nucleus ...

was identified as a comet using observations from the Discovery Channel Telescope. When the comet approached Earth within 2.2 million miles (about 9 lunar distances), the size of the nucleus to be calculated was 250 meters (820 feet) in diameter. The object was discovered by a

PanSTARRS The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1; obs. code: F51 and Pan-STARRS2 obs. code: F52) located at Haleakala Observatory, Hawaii, US, consists of astronomical cameras, telescopes and a computing facility that is ...

telescope, but not identified as a comet at that time. In 2017, the LDT achieved 282 nights out of the year (365 days) of scheduled observations for science.

Comparisons

References

External links