Gemini North telescope

The International Gemini Observatory consists of twin 8.1-meter diameter optical/infrared telescopes located on two of the best observing sites on the planet. The North telescope is located on Hawaii‘s Maunakea as part of the international community of observatories built to take advantage of the superb atmospheric conditions on this long-dormant volcano which rises about 4214 meters (13,825 feet) into the dry, stable air of the Pacific. Both of the Gemini telescopes have been designed to excel in a wide variety of optical and infrared capabilities. By incorporating technologies such as laser guide star adaptive optics and multi-object spectroscopy, astronomers in the Gemini partnership explore the universe in unprecedented depth and detail. The Gemini Observatory's international headquarters is located in Hilo, Hawai‘i at the University of Hawaii Hilo's University Park.

Gemini’s twin telescopes are optimized for observing in the mid-infrared with silver-coated mirrors, an extremely light structure for the secondary, and a light baffle (used when observing in the optical) which can be closed for observing in the infrared. The mirrors are f/1.8, 8.1 m diameter, 20 cm thick meniscus, and weighs 22,200 kg. Each was made from 55 blocks of low expansion (ULE-581) glass fused together at 1700 degrees C and slumped at Corning's Canton, New York facility. Each mirror blank was then shipped to REOSC Optique in Paris, France, for polishing of its reflecting surface to that of a concave hyperboloid. The measured surface accuracy is 15.6 nm (rms).

The Gemini telescopes have a suite of 4 optical and infrared, imagers and spectrographs, mounted on the back of the telescopes at the same time (as well as the acquisition and guidance instruments). This means that switching from one instrument to another takes a matter of minutes to complete before being capable of taking data on the next science target.

The Gemini North telescope is one of several telescopes near the summit (or in the summit area) of Maunakea, which is considered spiritual by a portion of the native Hawaiian community. 

Gemini is also unique among other 8-10 meter class observatories in that the telescopes can be (and usually are in the case of Gemini North) operated fully remotely from our base facilities.

Since 2002 Gemini North has also been known as the Frederick C. Gillett Gemini North telescope. 

Travel information for Gemini North is available here.

For scientists: More details can be found on the science telescope page.