Ōizumi Observatory

Ōizumi Observatory is a private astronomical observatory in Ōizumi, Gunma Prefecture, Japan, run by amateur astronomer Takao Kobayashi. Despite its modest size, it ranks among the most prolific minor-planet-hunting observatories anywhere.

About Ōizumi Observatory

The observatory, assigned Minor Planet Center observatory code 411, sits at around 38 metres above sea level in a relatively undisturbed corner of Gunma Prefecture, chosen to keep light pollution to a minimum. It is best known as the working observatory of Takao Kobayashi, whose systematic asteroid surveys have made Ōizumi one of the most productive amateur observatories in the world.

Telescopes & research

Kobayashi has used a 10-inch (250 mm) telescope at Ōizumi to search for minor planets since the early 1990s. Minor Planet Center records credit him with well over a thousand discoveries - some catalogues put the figure above 2,400 - including the periodic comet P/1997 B1 (Kobayashi). His work has been recognised in turn: asteroid 3500 Kobayashi is named in his honour.

Location & getting there

Ōizumi lies in Gunma Prefecture on Japan's main island of Honshu, part of the wider Kanto region north-west of Tokyo. The observatory's low elevation and quiet surroundings were deliberately chosen to limit interference from nearby city lights.

Visiting Ōizumi Observatory

As a privately run research observatory rather than a public attraction, Ōizumi does not offer regular public tours. If you would like to visit, check for current contact details and any scheduled open events before travelling.

See your named star from here

A dedicated minor-planet hunter like Ōizumi is proof of how much can be seen with a modest telescope pointed at the right coordinates. If you've named a star for someone, browse the star catalogue to find exactly where to look.