View source for UH88

{{short description|University of Hawai'i 88-inch telescope, at Mauna Kea Observatories}}
{{One source|date=July 2021}}
<!-- popups [[File:UH88 at sunset.jpg]] -->{{Infobox telescope|locmapin=USA Hawaii}}
The '''University of Hawaiʻi 88-inch (2.24-meter) telescope'''—called '''UH88''', '''UH2.2''', or simply '''88''' by members of the local astronomical community—is situated at the [[Mauna Kea Observatories]] and operated by the University's [[Institute for Astronomy (Hawaii)|Institute for Astronomy]]. It was constructed in 1968, and entered service in 1970, at which point it was known as "The Mauna Kea Observatory". It became one of the first professional telescopes to be controlled by a computer.<ref name=news/> The telescope was built with funding from NASA, to support [[Solar System]] missions, and is controlled by the [[University of Hawaiʻi]].<ref name=news/> The success of the telescope helped demonstrate the value of [[Mauna Kea]] for astronomical observations.<ref name=news/>

On December 4, 1984 it became the first telescope to make optical [[closure phase]] measurements on an astronomical source using an [[Aperture Masking Interferometry|aperture mask]]. 

UH88 is a [[Cassegrain reflector]] tube telescope with an f/10 [[focal ratio]], supported by a large open fork [[equatorial mount]]. It was the last telescope on Mauna Kea to use a tube design rather than an open truss, and is the largest in the complex to use an [[open fork mount]], with neighboring telescopes in the 3-meter class using [[English mount]] designs.

As the only research telescope controlled solely by the University, UH88 has long been the primary telescope used by its professors, postdoctoral scholars, and graduate students, and, as a result, the site of numerous discoveries. [[David C. Jewitt]] and [[Jane X. Luu]] discovered the first [[Kuiper belt]] object,<ref name=news/> [[15760 Albion]], using UH88, and a team led by Jewitt and [[Scott S. Sheppard]] discovered 45 of the known [[moons of Jupiter]], as well as moons of Saturn, Uranus and Neptune. 

The Institute for Astronomy also makes agreements with other organizations for portions of available observing time. Currently, the [[National Astronomical Observatory of Japan]] uses UH88 for some research projects for which its far larger and more expensive [[Subaru (telescope)|Subaru Observatory]], also on Mauna Kea, would be overkill. The [[Nearby Supernova Factory]] project, based at [[Lawrence Berkeley|Lawrence Berkeley National Laboratory]], also has its Supernova Integrated Field Spectrograph (SNIFS) instrument mounted on UH88.

In June 2011, the telescope and its weather station were struck by lightning, damaging many systems and disabling it, but the telescope was repaired by August 2011.<ref name=news>[http://www2.ifa.hawaii.edu/newsletters/article.cfm?a=549&n=45 UH IFA Newsletter No. 40 - 2011, UH 2.2-meter Telescope Recovers from Lightning Strike]</ref> Some of the systems at the observatory were 41 years old at the time of the damage and had to be [[reverse engineered]] to be fixed.<ref name=news/> The weather station is currently under development.

<gallery>
File:University of Hawaii Telescope. Mauna Kea Summit (503904) (21826273085).jpg|alt=The telescope building is pictured against a blue sky. The left side of the building is rectangular, while the right side is cylindrical and topped with the dome. The dome has a protrusion extending rightward. In the middle of this side of the building is the entrance. A black SUV is parked to the left of the entrance, and a white Jeep is parked on the horizon to the right of the building.|Telescope building
File:Hawaii - Big Island- UH 88-inch Telescope on Mauna Kea (14,000 ft) (6563839439).jpg|alt=On the left of the picture is a large medium brown cylinder oriented vertically; this is the telescope tube. The dark brown fork of the equatorial mount is in the foreground, connecting from its base at the bottom right to the side of the telescope tube. On the right, a person has reached the top of a staircase. At the top of the picture, an overexposed sky (appearing white) can be seen through the open observing slit.|A view inside the dome, showing the telescope and its equatorial mount
File:Hawaii - Big Island- UH 88-inch Telescope on Mauna Kea (14,000 ft) (6563853263).jpg|alt=A view looking up along the telescope tube. In the background, the open observing slit in the dome shows an overexposed sky. In the foreground, some electronic devices are mounted on the bottom end of the telescope tube, with messy cables. There are two orange boxes, two yellow racks of some kind, and a few other devices. On the side of the telescope tube directly in front of the camera is a narrow black cylinder; to its right, a set of weight plates is bolted to the telescope tube.|Hardware mounted on the bottom of the telescope tube
File:Hawaii - Big Island- UH 88-inch Telescope on Mauna Kea (14,000 ft) (6563844073).jpg|alt=A closeup of electronic devices mounted on the side of the telescope tube, a large brown cylinder. There is a lot of messy cabling, and there are some tubes with thermal insulation. One large piece of hardware, mounted to a circular feature on the side of the telescope tube, is covered with a thermal jacket as well. Written on the jacket with a marker are the names of color channels: "red", "green/photometric", and "blue". On the left and right sides of the picture, the dark brown arms of the equatorial mount fork extend from out of frame at the bottom corners up to the sides of the tube. Below the telescope tube and between the fork arms, the electronic gear shown in the previous picture is visible. Behind it, there is a view to the bottom of the dome, where various items are standing: a work cart, a stepladder, a pedestal fan, etc.|Hardware mounted on the side of the telescope tube
File:Hawaii - Big Island- UH 88-inch Telescope Control Room on Mauna Kea (14,000 ft) (6563855229).jpg|alt=An interior view of a curved, windowless room with desks along the sides. On the desks are computers and electronic instruments. In front of the desks are an oxygen bottle and an oscilloscope sitting next to an empty oscilloscope cart. Above the desks are shelves mounted to the walls, which hold more electronic instruments and a collection of binders. In the middle distance, three people (two seated and one standing) look at a computer screen which is hidden from our view by the curve of the room. In the background is an old Polycom video conferencing system with a large CRT TV on a cart, next to a bookshelf with magazine boxes, hard hats, and other items.|Control room
File:Hawaii - Big Island- UH 88-inch Telescope Control Room on Mauna Kea (14,000 ft) (6563864191).jpg|alt=A closeup of a handmade electronic control box on a control room desk. The box has a slanted front–top face equipped with a red rocker switch labeled "3 degree Override" and a large red button labeled "Emergency STOP". The horizontal top face of the box has two identical small black joysticks with rubber bellows, labeled with directions. Some of the labels are hidden and/or blurry, but the left joystick appears to be labeled "UP/DOWN/LEFT/RIGHT" and the right joystick appears to be labeled "S/N/E/W" (compass directions rotated 180° from the usual arrangement). The box's sides are blue and its face is gray. The labels were printed by a label maker, and have black text on a white background.|Control box, which appears to be for manually aiming the telescope
File:Hawaii - Big Island- UH 88-inch Telescope on Mauna Kea (14,000 ft) (6563825621).jpg|alt=A brass plaque with the negative space painted brown, in a brown wooden frame. The text on the plaque is transcribed on the picture's description page.|Commemorative plaque for the telescope
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==See also==
*[[List of largest optical telescopes in the 20th century]]

==References==
{{reflist}}
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[[Category:Astronomical observatories in Hawaii]]
[[Category:Buildings and structures in Hawaii County, Hawaii]]
[[Category:Reflecting telescopes]]