Akeno Giant Air Shower Array

At Akeno Observatory in Yamanashi Prefecture, Japan, the Akeno Giant Air Shower Array once spread more than a hundred particle detectors across the countryside to catch traces of the highest-energy cosmic rays ever measured.

About the Akeno Giant Air Shower Array

Known as AGASA, the array consisted of 111 scintillation detectors and 27 muon detectors spread over roughly 100 square kilometres, operated by the Institute for Cosmic Ray Research (ICRR) at the University of Tokyo. It was designed to study the origin of ultra-high-energy cosmic rays, some of the most energetic particles known to reach Earth.

History

AGASA was deployed between 1987 and 1991 and remained in operation until it was decommissioned in 2004.

Telescopes & research

Akeno Observatory, at roughly 900 metres elevation, continues to be used by ICRR for cosmic-ray and gamma-ray research, including studies of galactic cosmic-ray variation and observations connected to sources such as gamma-ray bursts and active galactic nuclei.

Location & getting there

The site is in the town of Akeno (now part of Hokuto), Yamanashi Prefecture, Japan, in the hills west of Tokyo.

Visiting the Akeno Giant Air Shower Array

This is a specialised scientific research facility rather than a public attraction, and the original AGASA array is no longer in place. If you're interested in the site, check with the Institute for Cosmic Ray Research directly before planning any visit.

See your named star from here

Cosmic-ray research and star naming both depend on precisely knowing where something sits in the sky. Every star in our star catalogue carries the same kind of celestial coordinates that facilities like Akeno use to trace particles back to their origin - if you've named a star, that's the data behind it.