About the Subaru Telescope

Director of the observatory


Director, Dr. Michitoshi Yoshida

photo: Director, Dr. Michitoshi Yoshida

Looking at the stars often bring us a sense of unlimited wonder and curiosity. Humankind lives in the very universe that created it.  It is perhaps this fundamental truth that we unconsciously think about when we look up at the sky.

In 1999, the Subaru Telescope saw first light, opening its eye to the universe. In the following year, the open use program started, allowing astronomers throughout the world to access the telescope. Subaru’s high-resolution observation became possible by various revolutionary technologies: an extremely smooth primary mirror; adaptive optics with 261 robotic fingers to maintain unprecedented  mirror surface accuracy; and a cylindrical enclosure design to reduce air turbulence. The Subaru Telescope has the strength and rigidity necessary to support an instrument at prime focus, allowing a very wide field of view. Thanks to these innovative technologies and careful designs, the Subaru Telescope has a significantly larger field of view compared to other large telescopes, while maintaining high resolution. In particular, one of our main instruments, Hyper Suprime-Cam (HSC) wide-field imaging camera takes advantage of these unique features of the Subaru Telescope. The high efficiency for sky surveys provided by HSC observations have facilitated a wide range of research areas. These include the exploration of the outer solar system; galaxy formation and evolution; and cosmology.

In order to complement the imaging capability of HSC, the next generation multi-fiber spectrograph, Prime Focus Spectrograph (PFS) is currently under development and will soon start its operation. This innovative instrument will enable us to take spectra of 2,400 astronomical objects simultaneously. There are other instruments that make use of Subaru’s high resolution capability. Using adaptive optics technology, the Subaru Telescope has been playing an active role in the study of exoplanets as well as the process of stellar and planetary formation.

Humankind has a feeling of longing when looking up at the night sky. Astronomers aim to unravel the feeling by solving mystery of the universe using scientific methods.  The National Astronomical Observatory of Japan built the Subaru Telescope to continue the exploration of the universe, inheriting the dreams of human beings throughout time. By developing new instruments and continual innovation, we strive to maintain Subaru Telescope’s status as the world-leading optical-infrared telescope.