VLTI

Angular resolution describes the resolving power of a telescope. Angular resolution - Definition of terms. Resolving power is the ability of a microscope or telescope to measure the angular separation of images that are close together. Resolution is the minimum distance between distinguishable objects, in microscopy. These terms also apply to other angle and position measuring devices. Resolution, more generally, is the precision of any instrument to measure a continuous variable ...

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• Angular resolution - Definition of terms
• Angular resolution - Explanation
• Angular resolution - Telescope case
• Angular resolution - Microscope case

Read more here: » Angular resolution: Encyclopedia - Angular resolution

The CHARA Array is an astronomical optical interferometer operated by The Center for High Angular Resolution Astronomy (CHARA) at Georgia State University. CHARA is the World's highest angular resolution telescope at infrared wavelengths. The array will eventually have six 1-metre diameter telescopes, making it one of the most powerful imaging interferometers in the world. CHARA array - Related pages. Similar imaging interferometers include COAST, NPOI and more recently VLTI/AMB ...

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• CHARA array - Related pages

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Red dwarfs in general are far too weak to be observable with the naked eye, and Proxima Centauri is no exception. It has an apparent magnitude of 11 while its absolute magnitude is a very weak 15.5. Seen from Alpha Centauri A or B, Proxima would be a 4.5 magnitude star. Based on the parallax of 772.33 ± 2.42 milliarcseconds measured by Hipparcos, Proxima Centauri is roughly 4.22 light years from Earth, or 270,000 times more distant than the Sun. Its closest neighbours are Alpha Centauri A and B (at 0.21 light years), t ...

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Proxima Centauri, Proxima Centauri - Characteristics, Proxima Centauri - Traveling to Proxima Centauri, Proxima Centauri - In fiction and games

Read more here: » Proxima Centauri: Encyclopedia II - Proxima Centauri - Characteristics

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

The resolving power of a lens is ultimately limited by diffraction effects. The lens' aperture is a "hole" that is analogous to a two-dimensional version of the single-slit experiment; light passing through it interferes with itself, creating a ring-shaped diffraction pattern, known as the Airy pattern, that blurs the image. An empirical diffraction limit is given by the Rayleigh criterion: where θ is the angular resolution, λ is the wavelength o ...

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Angular resolution, Angular resolution - Definition of terms, Angular resolution - Explanation, Angular resolution - Telescope case, Angular resolution - Microscope case

Read more here: » Angular resolution: Encyclopedia II - Angular resolution - Explanation

Point-like sources separated by an angle smaller than the angular resolution cannot be resolved. A single optical telescope has an angular resolution less than one arcsecond, but astronomical seeing and other atmospheric effects make attaining this very hard. The highest angular resolutions can be achieved by interferometry: the VLTI is intended to achieve an effective angular resolution of 0.001 arcsecond. The angular resolution of a telescope can usually be approximated by R = λ/D where λ is the wavelen ...

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Angular resolution, Angular resolution - Definition of terms, Angular resolution - Explanation, Angular resolution - Telescope case, Angular resolution - Microscope case

Read more here: » Angular resolution: Encyclopedia II - Angular resolution - Telescope case

The resolution D depends on the angular aperture α: . Here α is the collecting angle of the lens, which depends on the width of objective lens and its distance from the specimen. n is the refractive index of the medium in which the lens operates. λ is the wavelength of light illuminating or emanating from (in the case of fluorescence microscopy) the sample. Due to the limitations of the values α, λ, and n, the resolution limit of a light mic ...

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Angular resolution, Angular resolution - Definition of terms, Angular resolution - Explanation, Angular resolution - Telescope case, Angular resolution - Microscope case

Read more here: » Angular resolution: Encyclopedia II - Angular resolution - Microscope case

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