List of astronomical interferometers at visible and infrared wavelengths

The Very Large Telescope Project (VLT) consists of a system of four separate optical telescopes (the Antu telescope, the Kueyen telescope, the Melipal telescope, and the Yepun telescope) organized in an array formation. Each telescope has an 8.2 m aperture. The project is organized by the European Southern Observatory. VLT is located at the Paranal Observatory on Cerro Paranal, a 2,635 m high mountain in the Atacama desert in northern Chile. Very Large Telescope - General informa ...

Including:

• Very Large Telescope - General information
• Very Large Telescope - Interferometry and the VLTI

Read more here: » Very Large Telescope: Encyclopedia - Very Large Telescope

The VLT consists of a cluster of four large (8.2 meter diameter) telescopes, and an interferometer (VLTI) which is used to resolve fine features. The interferometer will include a set of 1.8 meter diameter telescopes dedicated to interferometric observations. The 8.2 meter telescopes have been named after the names of some astronomical objects in the local Mapuche language: Antu (The Sun), Kueyen ...

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Very Large Telescope, Very Large Telescope - General information, Very Large Telescope - Interferometry and the VLTI

Read more here: » Very Large Telescope: Encyclopedia II - Very Large Telescope - General information

Later, optical interferometry was used on the Mount Wilson Observatory's reflector telescope in order to measure the diameters of stars. This method was extended to measurements using separated telescopes by Johnson, Betz and Towns (1974) in the infrared and by Labeyrie (1975) in the visible. The red giant star Betelgeuse was among the first to have its diameter determined in this way. In the 1980s the aperture synthesis technique was extended to visible light and infrared astronomy by the Cavendish Astrophysics Group, providing the first ve ...

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Optical interferometry, Optical interferometry - Astronomical optical interferometry, Optical interferometry - For further information see, Optical interferometry - The Michelson-Morley experiment, Optical interferometry - Geodetic standard baseline measurements, Optical interferometry - Holography, Optical interferometry - Inertial navigation

Read more here: » Optical interferometry: Encyclopedia II - Optical interferometry - Astronomical optical interferometry

Most interferometry will be done using 1.8 meter Auxiliary Telescopes (ATs), which will be dedicated to full-time interferometric measurements. The first observations using a pair of ATs were conducted in February 2005, and additional ATs are expected to be installed soon. For interferometric observations on the brightest objects, there is little benefit in using 8 meter telescopes rather than 1.8 meter telescopes. In its interferometric operating mode, the light from the telescopes is reflected off mirrors and directed through tunnel ...

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Very Large Telescope, Very Large Telescope - General information, Very Large Telescope - Interferometry and the VLTI

Read more here: » Very Large Telescope: Encyclopedia II - Very Large Telescope - Interferometry and the VLTI

A famous use of white light interferometry is the precise measurement of geodetic standard baselines as invented by Yrjö Väisälä. Here, the light path is split in two, and one leg is "folded" between a mirror pair 1 m apart. The other leg bounces once off a mirror 6 m away. Only if the second path is precisely 6 times the first, will fringes be seen. Starting from a standard quartz gauge of 1 m length, it is possible to measure distances up to 864 m by repeated multiplication. Baselines thus established are used to calibrate geodetic distance measurement equipment on, leading to a m ...

See also:

Optical interferometry, Optical interferometry - Astronomical optical interferometry, Optical interferometry - For further information see, Optical interferometry - The Michelson-Morley experiment, Optical interferometry - Geodetic standard baseline measurements, Optical interferometry - Holography, Optical interferometry - Inertial navigation

Read more here: » Optical interferometry: Encyclopedia II - Optical interferometry - Geodetic standard baseline measurements

An interferometer works on the principle that two waves that coincide with the same phase will amplify each other while two waves that have opposite phases will cancel each other out. In the beginning, most interferometers used white light sources (e.g., Young's double slit experiment of 1805). Nowadays researchers often use monochromatic light sources like lasers, and even the wave character of matter can be exploited to build interferometers. One of the first examples of matter interferometers were electron interferometers, later fo ...

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Interferometry, Interferometry - Interferometer, Interferometry - Related lists

Read more here: » Interferometry: Encyclopedia II - Interferometry - Interferometer

George Ellery Hale received the 60 inch (1.5 m) blank mirror, cast by Saint Gobain in France, in 1896 as a gift from his father, William Hale. It was a glass disk 7 1/2 inches (191 mm) thick and weighing 1900 pounds (860 kg). However it was not until 1904 that Hale received funding from the Carnegie Institution to build an observatory. Grinding began in 1905 and took two years. The mounting and structure for the telescope was built in San Francisco and barely survived the 1906 earthquake. Transporting the pieces to the top of Mount Wilson wa ...

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Mount Wilson Observatory, Mount Wilson Observatory - 60 inch 1.5 m Hale telescope, Mount Wilson Observatory - 100 inch 2.5 m Hooker telescope, Mount Wilson Observatory - Solar telescopes, Mount Wilson Observatory - Interferometry

Read more here: » Mount Wilson Observatory: Encyclopedia II - Mount Wilson Observatory - 60 inch 1.5 m Hale telescope

Hale immediately set about creating a larger telescope. John D. Hooker provided crucial funding for it, along with Carnegie. The Saint Gobain factory was again chosen to cast a blank in 1906, which it completed in 1908, After considerable trouble over the blank (and potential replacements), the 100 inch (2.5 m) telescope was completed and saw "first light" on November 1, 1917. The mechanism incorporates a mercury float to provide smooth operation. The Hooker telescope was equipped in 1919 with a special attachment, an optical interfer ...

See also:

Mount Wilson Observatory, Mount Wilson Observatory - 60 inch 1.5 m Hale telescope, Mount Wilson Observatory - 100 inch 2.5 m Hooker telescope, Mount Wilson Observatory - Solar telescopes, Mount Wilson Observatory - Interferometry

Read more here: » Mount Wilson Observatory: Encyclopedia II - Mount Wilson Observatory - 100 inch 2.5 m Hooker telescope