Narrabri Stellar Intensity Interferometer

The Narrabri Stellar Intensity Interferometer is a facility with a circular track where two light detectors are positioned. These detectors can be placed between 10 and 188 meters apart to take measurements of star angular size.

The facility was founded in 1963 by the University of Sydney School of Physics and operated until 1974. During this period it made possible the measurement of 32 different stars using previously untested methods.

The facility was an important sign of scientific collaboration between Australia and Britain during the 1960s. Visitors can still see traces of this international research partnership at the observatory grounds today.

The site is located in a remote area of Narrabri Observatory in New South Wales and requires planning ahead for a visit. It is wise to check access rules in advance and allow adequate time to explore the facility.

The instrument was the first to successfully measure star diameters using visible light through intensity interferometry. This approach made it possible to observe stars in a new way without building the larger telescopes available at the time.

Location: New South Wales

GPS coordinates: -30.20920,149.75100

Latest update: December 14, 2025 13:05