Image Caption: The Subaru Telescope at the Mauna Kea Observatory on Hawaii. Credit: Denys/Wikipedia (CC BY-SA 3.0)
The Subaru Telescope is a 26.9-foot (8.2m) telescope located at the Mauna Kea Observatory on the Big Island of Hawaii and operated by the National Astronomical Observatory of Japan (NAOJ). It had the largest primary mirror in the world until 2005.
This is a reflecting telescope with a large field of view–called a Ritchey-Chretien–which has a primary mirror and a secondary mirror to eliminate optical errors. Extra instruments can be mounted below the primary mirror on the sides of the telescope mount to direct light onto the primary mirror, providing an even wider field of view.
In 1984, the University of Tokyo studied the concept of developing a 24.6-foot (7.5m) telescope. In 1985, the study was given top priority to develop it, and in 1986 UTokyo signed an agreement with the University of Hawaii to have the telescope built in Hawaii. In April 1991, construction began and a public contest was created to give the telescope its official name, “Subaru Telescope.” The project was completed in 1998 and the first images were taken in January 1999.
There are 261 computer controlled actuators on the back of the primary mirror to correct distortion. Image quality is improved from the design of the building that houses the telescope, by minimizing air turbulence. The Subaru Telescope could be used with the naked eyed initially, but after the dedication of the telescope by Princess Sayako and a few nights of staff enjoying the views, it was replaced with more sensitive instruments.
These instruments include a Multi-Object Infrared Camera and Spectrograph to give a wide field of view and capable of capturing multiple images simultaneously; A cooled mid-infrared camera and spectrometer, to study interstellar dust; A faint object camera which can take up to 100 objects at the same time; An 80 mp wide-field visible light camera; A visible light spectrograph, an infrared spectrograph using fiber optics to take spectra of up to 400 objects at the same time; An infrared camera to search for planets around other stars, and a 900 mp ultra wide camera built onto the telescope in 2011, used to determine dark matter distribution. The lenses were manufactured by Canon.
During the construction of the telescope two fatal incidences occurred. On October 13, 1993, Paul F. Lawrence died when a fork lift rolled over on him. And on January 16, 1996, three other workers were fatally injured and 26 workers were hospitalized when a spark ignited some insulation and released noxious smoke. The workers killed were, Marvin Arruda, 52, Ricky Del Rosario, 38, and Warren K. “Kip” Kaleo, 36. The names of the four workers who were fatally injured during construction are written on a plaque and placed outside the base of the telescope dome every January in remembrance of them.
On July 2, 2011, the telescope operator in Hilo reported an anomaly on the top unit. It was discovered that coolant leaked over the primary mirror and onto other parts. Full operation of the telescope resumed on August 26.
Latest news and discoveries can be seen at the official Subaru Website.