Nishi-Harima Astronomical Observatory is located in Sayo Town, Sayo District, Hyogo Prefecture. Surrounded by nature and blessed with dark skies ideal for stargazing, it is a destination where visitors can discover the wonders of the universe. The facility was operated as a public observatory until March 2012. In April 2012, it was transferred to the Institute of Natural and Environmental Sciences at the University of Hyogo, and since April 2014, it has operated as the University of Hyogo Nishi-Harima Astronomical Observatory.
The observatory holds astronomical observation sessions every night, giving visitors opportunities to observe celestial objects through powerful telescopes. Guests can also stay overnight at accommodation facilities within the grounds, making it possible to enjoy the night sky well into the early hours of the morning.
Throughout the year, the observatory hosts astronomy lectures and special events. Visitors can also explore exhibitions featuring meteorites and other astronomy-related materials. The facility combines public outreach with university education and scientific research, offering experiences for everyone from first-time stargazers to astronomy enthusiasts.
The observatory complex includes observation domes and buildings, exhibitions about space and astronomy, outdoor displays, educational facilities for schools, lifelong learning facilities, and research laboratories.
Public activities include guided facility tours, stargazing sessions, astronomy lectures, and events designed to deepen understanding of the universe. The observatory also supports university-level education and provides researchers with access to its facilities and instruments.
One of the observatory’s most important facilities is the South Observatory Building, home to Nayuta, a large reflecting telescope with an effective aperture of 2,000 millimeters. When it achieved first light in October 2004, it was the largest telescope in Japan and, at the time, the largest telescope available for public use anywhere in the world.
General public use and scientific research with Nayuta began in November 2004. In February 2016, its two-meter primary mirror was refreshed through a recoating process, helping maintain its observing performance.
Effective aperture: 2,000 mm.
Primary mirror diameter: 2,050 mm.
Primary mirror focal ratio: f/1.5.
Optical design: Ritchey–Chrétien.
Primary mirror material: ULE glass, a type of glass with an extremely low coefficient of thermal expansion.
Observing range: Visible light to near-infrared, including the K band.
Mount: Altazimuth mount with a friction-drive system and fully automated control.
The telescope is equipped with a range of instruments for different kinds of astronomical research. These include the high-sensitivity color camera HIVISCAS and the visible-light spectrograph MALLS at the Nasmyth foci, as well as the visible-light imaging instrument MINT, the three-color simultaneous near-infrared camera NIC, and the visible-light target observation system VTOS at the Cassegrain focus.
The North Observatory Building houses a 60-centimeter reflecting telescope with a Cassegrain optical design and a combined focal length of 7,200 millimeters. A 350-millimeter Schmidt–Cassegrain telescope is mounted alongside it.
Star Plaza provides additional opportunities for observing the sky, with a 15-centimeter refracting telescope, large 10-centimeter binoculars, and a solar telescope known as Kirakira Tonbo.
Two satellite observatories are available for rental, allowing visitors and groups to enjoy more independent observing experiences. Satellite A has a three-meter dome and a 26-centimeter reflecting telescope made by Mikage Optical Instruments. Satellite B has a 2.5-meter dome and an 18-centimeter reflecting telescope manufactured by Takahashi Seisakusho.
The rest area includes a Family Dome equipped with a 30-centimeter, f/5 Newtonian reflecting telescope, the Magellan WHITEY DOB. These facilities provide additional ways to explore the night sky in a relaxed setting.
The observatory also has equipment for radio astronomy and solar observation. This includes a 12-GHz solar radio burst telescope adapted from a satellite broadcast antenna, along with riometers operating at 38 MHz and 22 MHz.
A variety of telescopes are also available for loan, supporting educational activities and personal observing experiences.
As part of the University of Hyogo, Nishi-Harima Astronomical Observatory contributes to university education and scientific research. Its observing facilities are made available to researchers from universities and other institutions, supporting astronomical observation and related studies.
The observatory also works with schools to support science education and provides opportunities for the wider public to learn about astronomy. Through lectures, public observing sessions, exhibitions, and educational programs, it helps make the study of the universe accessible to people of different ages and backgrounds.
1990: The observatory opened to the public, with the North Observatory Building serving as its principal facility.
April 2001: Plans for a large telescope project began.
October 2004: The Nayuta telescope achieved first light.
November 2004: General public observing and scientific research using Nayuta began.
February 2016: The telescope’s two-meter primary mirror was recoated to restore its reflective surface.
Address: 407-2 Nishikawachi, Sayo Town, Sayo District, Hyogo Prefecture 679-5313, Japan.
By train and taxi: Take the JR Kishin Line or the Chizu Express Chizu Line to Sayo Station, then continue by taxi for approximately 15 minutes.
From Himeji: Access is possible by train via Harima-Shingu Station. An express bus service operated by Shinki Bus from Himeji Station was suspended on March 31, 2023, so visitors should plan an alternative route.
With its powerful Nayuta telescope, multiple observation facilities, and regular public stargazing sessions, Nishi-Harima Astronomical Observatory offers a memorable introduction to astronomy. Visitors can look beyond the familiar night sky, learn about ongoing scientific research, and experience the beauty of the universe in the natural surroundings of Sayo Town.