Bisei Observatory - Japan's First Light Pollution Prevention Ordinance Protecting Okayama's Starry Sky

Overview

Bisei Observatory is a public astronomical observatory located on a hill at approximately 450 meters elevation in Bisei Town, Ibara City, Okayama Prefecture. Bisei Town is known as the first municipality in Japan to enact a light pollution prevention ordinance (the Bisei Town Light Pollution Prevention Ordinance for Protecting Beautiful Starry Skies) in 1989, and the entire town is committed to preserving the night sky environment.

Equipped with a 101-centimeter reflector telescope, you can enjoy full-scale celestial observations under a beautiful starry sky preserved through community-wide efforts.

Observation Environment

The light pollution prevention ordinance in Bisei Town promotes the extinguishing of unnecessary outdoor lighting after 22:00 throughout the town. As a result of this initiative, even in the town center, the darkness is maintained such that the Milky Way is visible to the naked eye.

The area around the observatory has even better conditions, with a Bortle scale class of approximately 2. The results of over 30 years of light pollution suppression since the ordinance came into effect are evident in the darkness of the night sky.

Additionally, Okayama Prefecture, true to its nickname "the Prefecture of Clear Skies," boasts one of Japan's highest clear-sky rates, making it easy to obtain weather conditions suitable for celestial observations throughout the year.

Facilities and Usage Information

The 101-centimeter reflector telescope is open to the public during nighttime hours on Friday, Saturday, Sunday, and Monday. Professional staff provide guided tours with explanations of seasonal celestial objects, so beginners can feel assured. During the daytime, solar observations and visits to the exhibition room are possible.

In front of the observatory is a grass plaza where you can enjoy naked-eye stargazing while lying down. It's recommended to bring a leisure sheet.

Access

About 40 minutes by car from Kasaoka IC on the Sanyo Expressway, and about 1 hour from central Okayama. As bus service is limited, a car visit is essential.

Observation Tips

While Okayama has a high clear-sky rate, there may be extended cloudy periods during the rainy season or when the autumn rain front is present. Check the weather forecast before your visit. Bisei Town is a relatively warm region, but due to its 450-meter elevation, winter nights can be cold. Don't forget warm clothing.