Narrabri Stellar Intensity Interferometer
Encyclopedia
The Narrabri Stellar Intensity Interferometer (NSII) was the first astronomical instrument to measure the diameters of a large number of star
s at visible wavelengths. It was designed by (amongst others) Robert Hanbury Brown
, who received the Hughes Medal
in 1971 for this work. It was built by University of Sydney
School of Physics and was located near the town of Narrabri in north-central New South Wales
, Australia
. The design was based on an earlier optical intensity interferometer
built by Hanbury Brown and Richard Q. Twiss
at Jodrell Bank
in the UK
. The NSII operated from 1963 until 1974, and was used to measure the angular diameters of 32 stars.
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s at visible wavelengths. It was designed by (amongst others) Robert Hanbury Brown
Robert Hanbury Brown
Robert Hanbury Brown, AC FRS was a British astronomer and physicist born in Aruvankadu, India. He made notable contributions to the development of radar and he later conducted pioneering work in the field of radio astronomy...
, who received the Hughes Medal
Hughes Medal
The Hughes Medal is awarded by the Royal Society of London "in recognition of an original discovery in the physical sciences, particularly electricity and magnetism or their applications". Named after David E. Hughes, the medal is awarded with a gift of £1000. The medal was first awarded in 1902 to...
in 1971 for this work. It was built by University of Sydney
University of Sydney
The University of Sydney is a public university located in Sydney, New South Wales. The main campus spreads across the suburbs of Camperdown and Darlington on the southwestern outskirts of the Sydney CBD. Founded in 1850, it is the oldest university in Australia and Oceania...
School of Physics and was located near the town of Narrabri in north-central New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. The design was based on an earlier optical intensity interferometer
Intensity interferometer
An intensity interferometer is the name given to devices that use the Hanbury-Brown and Twiss effect. In astronomy, the most common use of such an astronomical interferometer is to determine the apparent angular diameter of a radio source or star...
built by Hanbury Brown and Richard Q. Twiss
Richard Q. Twiss
Richard Q. Twiss is famous for his work on the Hanbury-Brown and Twiss effect with Robert Hanbury Brown. This led to the development of the Hanbury Brown-Twiss intensity interferometer in the UK in 1954. Their work was controversial as it appeared to contradict the established beliefs about...
at Jodrell Bank
Jodrell Bank
The Jodrell Bank Observatory is a British observatory that hosts a number of radio telescopes, and is part of the Jodrell Bank Centre for Astrophysics at the University of Manchester...
in the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
. The NSII operated from 1963 until 1974, and was used to measure the angular diameters of 32 stars.