The Subaru Telescope is located on the summit of Mt. Mauna Kea in Hawaii. Canon's optical and precision technologies are utilized in this optical infrared telescope, which is used every night to search for the secrets of the birth of the universe.
Canon Technology Supporting New Discoveries in Space
The Subaru Telescope, operated by the National Astronomical Observatory of Japan, is located on the summit of Mt. Mauna Kea in Hawaii. The most notable feature of the Subaru Telescope is that it is the only 8-meter-class telescope equipped with a prime-focus camera. The lens unit used in the prime-focus camera was developed by Canon. Thanks to the excellent resolving power offered by the corrective optic system, the Subaru Telescope has been producing numerous astonishing results, including the discovery of a galaxy (IOK-1) located approximately 12.88 billion light years from Earth.
The Subaru Telescope's prime focus can be used to observe a wide field of view of 0.5 degrees, which is almost the same as the diameter of the moon and 25 times wider than the field of view of the Cassegrain focus (field of view: 0.1 degrees). Comprising seven large elements in five groups, the prime-focus lens unit created by Canon has an aperture of 520 mm and weighs 170 kg, making it the largest lens unit constructed by the company while also achieving an unprecedentedly compact and lightweight design for a prime-focus camera.
Furthermore, the lens unit is capable of correcting for atmospheric dispersion*1 with a high degree of accuracy. This is achieved through Canon's original system, which uses two lenses made of materials with different dispersion characteristics, positioned at right angles to the optical axis to correct for atmospheric dispersion.
- *1 Atmospheric dispersion
A phenomenon in which the light from stars appears blurred due to the differences in refractive indices of the atmosphere by wavelength when light reaches the Earth's atmosphere.
Canon Technology Supporting the Search for the Unknown in Space
It is believed that dark matter, which accounts for roughly 23% of the universe, holds the key to the birth of the universe, and that dark energy, which accounts for roughly 73% of the universe, will determine its future. Therefore, understanding the true nature of these as yet unknown elements is one of the most important issues in the fields of astronomy and physics.
The National Astronomical Observatory of Japan is working together with Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) in its search to discover the true nature of dark matter and dark energy. The project calls for the Subaru Telescope to be fitted with a new prime-focus camera to enhance its field of view from the current 0.5 degrees to 1.5 degrees, enabling the observation of multiple galaxies in a short space of time, including distant and dark galaxies, as well as precise measurements of the dimensions of these galaxies. Also, by using the gravitational lens*2 effect, the project will attempt to create a 3-D map of dark matter, and to investigate the true nature of dark matter and dark energy.
In order to support the realization of this project, Canon is working to develop a corrective optical system for a new prime-focus camera to increase the field of view to 1.5 degrees. The optical system comprises seven large elements including five large-aperture, high-precision aspherical lens elements, the largest of which with an aperture exceeding 850 mm. This was made possible by Canon's advanced processing and measurement technologies, including the super-smooth polishing of aspherical surfaces, which combines the company's technologies and know-how accumulated over many years of development for the optical systems used in semiconductor lithography equipment, and large aspherical surface measuring, which becomes increasingly difficult with larger lens apertures.
Design of the Subaru Telescope
- *2 Gravitational lens
A phenomenon whereby the light from stars, galaxies and other astronomical bodies appears bent and distorted by the gravitational pull of astronomical bodies on the light path, and where multiple images can be observed.
