Gemini Observatory

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For Other uses of Gemini, see Gemini.

Gemini Observatory

Organization

Gemini Consortium and AURA

Location

Mauna Kea, Hawai'i
Cerro Pachón, Chile

Coordinates

19°49′25.7016″N, 155°28′08.616″W
30°14′26.700″S, 70°44′12.096″W

Altitude

4213 m
2722 m

Established

2000

Website
Gemini Observatory

Telescopes
Gemini North	8.1 m Cassegrain reflector
Gemini South	8.1 m Cassegrain reflector

The Gemini Observatory is an astronomical observatory consisting of two 8-metre telescopes at different sites. The Northern Operations Center is located in Hilo, Hawaii, and the Southern Operations Center is in La Serena, Chile. The Gemini telescopes were built and are operated by a consortium consisting of the United States, United Kingdom, Canada, Chile, Brazil, Argentina, and Australia. This partnership is managed by the Association of Universities for Research in Astronomy (AURA). The United Kingdom had dropped out of the partnership in late 2007, only to be re-instated again two and a half months later.

One telescope (Gemini North, also called the Frederick C. Gillett telescope) is located on Hawaii's Mauna Kea. Its location makes for excellent viewing conditions due to the superb atmospheric conditions on top of the over 4200 m (13,800 ft) high dormant volcano. It saw first light in 1999 and began scientific operations in 2000.

The other (Gemini South) is located at over 2700 m (9000 ft) elevation on a mountain in the Chilean Andes called Cerro Pachón. Very dry air and negligible cloud cover make this another prime telescope location (shared by several other observatories, including the SOAR Telescope and Cerro Tololo Inter-American Observatory). Gemini South saw first light in 2000.

The Gemini Observatory's international headquarters is located in Hilo, Hawaii at the University of Hawaii at Hilo University Park. The Gemini South base-facility is located on the Cerro Tololo Inter-American Observatory (CTIO) campus in La Serena Chile.

Together, the twin Gemini telescopes provide almost complete coverage of both the northern and southern skies (Gemini North presently cannot point north of declination +79 degrees; Gemini South cannot point south of declination -89 degrees). They are currently among the largest and most advanced optical/infrared telescopes available to astronomers. Both employ a range of advanced technologies to deliver the highest quality images, including laser guide stars, adaptive optics and multi-object spectroscopy. In addition, the two telescopes allow very high-quality infrared observations due to the advanced protected silver coating of their mirrors and advanced ventilation systems. Thanks to a high degree of networking, the Gemini telescopes can be operated remotely, and observations can be run when atmospheric conditions suit them best, reducing unnecessary travel by astronomers.

It is estimated that the two telescopes cost approximately $184 million to construct, and a night on each Gemini telescope is worth about $40,000.

The history of the Gemini Observatory featured prominently in Giant Telescopes, a 2004 book by science historian W. Patrick McCray [1]. It details the technical and political challenges faced by scientists and engineers working to construct Gemini and other modern observatories.

In November 2007 it was announced that the UK's STFC had proposed that, to save £4 million annually, it would aim to leave the telescope's operating consortium.

At a consortium in January 2008, the conclusion was made that the UK would officially withdraw from the Gemini Partnership and the Gemini Observatory Agreement effective December 12, 2007.

As the reason for the UK breaking its part of the agreement seemed to be entirely financial, there had been public outcry, including the "Save Astronomy" movement [2] which is asking citizens to speak up against the astronomy budget cuts.

The UK rethought their decision to withdraw from Gemini, and requested reinstatement into the agreement, and as of February 27, 2008, were officially welcomed back. They will seek to sell some of their telescope time to bring in the much-needed funds to continue their commitment to the agreement.

The two 8 meter mirror blanks, each weighing over 24 tons, were fabricated from Corning's Ultra Low Expansion glass. Each blank was constructed by the fusing together of and subsequent sagging of a series of smaller hexagonal pieces. This work was performed at Corning's Canton Plant facility located in upstate New York. The blanks were then transported via ship to REOSC, located south of Paris, France for final grinding and polishing.