Editing Lowell Observatory (section)

=== Lowell Discovery Telescope ===
{{main article|Lowell Discovery Telescope}}
Lowell Observatory owns and operates the Lowell Discovery Telescope (LDT, formerly the Discovery Channel Telescope) located near [[Happy Jack, Arizona]]. This 4.3-meter [[reflecting telescope]] is the fifth-largest telescope in the contiguous United States and one of the most powerful in the world, thanks to a unique instrument cube that can accommodate up to five instruments at the Ritchey-Chrétien focus, four via fold mirrors and another at the bore sight. The LDT can switch between any of these instruments in about a minute by placing or removing these fold mirrors in the optical path of the instrument cube, making it uniquely suited for time-domain programs as well as opportunity targets such as gamma ray bursts and supernovae.

The 6700-pound [[primary mirror]] measures {{convert|4.3|m|in|abbr=on}} in diameter yet only about {{convert|10|cm|in|abbr=on}} in thickness. This finely figured, thin meniscus mirror, held in shape by a 156-element active optics system, 120 lateral pistons and 36 lateral supports, regularly delivering sub-arcsecond seeing. The mirror was ground and polished into its [[Hyperbolic functions|hyperbolic]] shape at the Optical Fabrication and Engineering Facility of the College of Optical Sciences of the [[University of Arizona]] in [[Tucson, Arizona|Tucson]].

The LDT is housed in a 73-foot-tall, 62-foot-diameter metal dome located at an elevation of {{convert|7,800|ft}} and about {{convert|40|mi}} southeast of Flagstaff. Groundbreaking for the facility occurred on July 11, 2005.  A little over six years later, the first image from just the primary mirror was recorded, using a small test camera mounted where the secondary mirror would eventually go. The secondary mirror was installed in January 2012. To celebrate first light, Lowell hosted a gala celebration on July 21, 2012, featuring a keynote address by [[Neil Armstrong]]. This was his final public appearance before his death several weeks later.

The telescope is named for the [[Discovery Channel]] television network. Discovery founder and CEO [[John Hendricks]] has long been a member of Lowell Observatory's Advisory Board, and Discovery and John and his wife Maureen made gifts of $16 million toward the $53 million cost of the project. These were gifts, not purchases: Discovery has no ownership in the telescope, nor any direction of the research conducted with it. In return for their contributions, they received naming rights and first right of refusal for use of images in educational broadcasts. Research use proceeds as it would at any other professional telescope.

[[Boston University]], the [[University of Maryland]], the [[University of Toledo]], [[Northern Arizona University]], and [[Yale University]] have joined Lowell as partners with access to DCT.