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Astronomical Optical Interferometry
In optical astronomy, interferometry is used to combine signals from two or more telescopes to obtain measurements with higher resolution than could be obtained with either telescopes individually. This technique is the basis for astronomical interferometer arrays, which can make measurements of very small astronomical objects if the telescopes are spread out over a wide area. If a large number of telescopes are used a picture can be produced which has Angular resolution, resolution similar to a single telescope with the diameter of the combined spread of telescopes. These include radio telescope arrays such as Very Large Array, VLA, VLBI, Submillimeter Array, SMA, Low-Frequency Array (LOFAR), LOFAR and Square Kilometre Array, SKA, and more recently Optical interferometry#Astronomical optical interferometry, astronomical optical interferometer arrays such as Cambridge Optical Aperture Synthesis Telescope (COAST), COAST, Navy Prototype Optical Interferometer, NPOI and Infrared Opt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Astronomy
Visible-light astronomy encompasses a wide variety of observations via telescopes that are sensitive in the range of visible light (optical telescopes). Visible-light astronomy is part of optical astronomy, and differs from astronomies based on invisible types of light in the electromagnetic radiation spectrum, such as radio waves, infrared waves, ultraviolet waves, X-ray waves and gamma-ray waves. Visible light ranges from 380 to 750 nanometers in wavelength. Visible-light astronomy has existed as long as people have been looking up at the night sky, although it has since improved in its observational capabilities since the invention of the telescope, which is commonly credited to Hans Lippershey, a German-Dutch spectacle-maker, although Galileo played a large role in the development and creation of telescopes. Visible-light astronomy continues to get better in the modern day, with projects such as the James Webb Space Telescope. Since visible-light astronomy is restricted t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CHARA Array
The CHARA (Center for High Angular Resolution Astronomy) array is an optical interferometer, located on Mount Wilson, California. The array consists of six telescopes operating as an astronomical interferometer. Construction was completed in 2003. CHARA is owned by Georgia State University (GSU). Functionality CHARA’s six telescopes each have a one-meter diameter mirror to reflect light. They are spread across Mount Wilson to increase the angular resolution of the array. Each of the six telescopes provides a different image, to combine it into one image the light from each telescope is transported through vacuum tubes and fed into a single beam, where they are matched up to within one micron. This process is called interferometry, and allows the array to have the same resolving power as a telescope with a 330-meter mirror, and an angular resolution of 200 micro-arcseconds. History In 1984 CHARA was founded, and with financial support from the National Science Foundation ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavendish Astrophysics Group
The Cavendish Astrophysics Group (formerly the Radio Astronomy Group) is based at the Cavendish Laboratory at the University of Cambridge. The group operates all of the telescopes at the Mullard Radio Astronomy Observatory except for the 32m MERLIN telescope, which is operated by Jodrell Bank. The group is the second largest of three astronomy departments in the University of Cambridge. Instruments under development by the group * The Atacama Large Millimeter Array (ALMA) - several modules of this international project * The Magdalena Ridge Observatory Interferometer (MRO Interferometer) * The SKA Instruments in service * The Arcminute Microkelvin Imager (AMI) * A Heterodyne Array Receiver for B-band (HARP-B) at the James Clerk Maxwell Telescope * The Planck Surveyor Previous instruments * The CLOVER telescope * The Very Small Array * The 5 km Ryle Telescope * The Cambridge Optical Aperture Synthesis Telescope (COAST) * The Cosmic Anisotropy Telescope * The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palomar Testbed Interferometer
The Palomar Testbed Interferometer (PTI) was a near infrared, long-baseline stellar interferometer located at Palomar Observatory in north San Diego County, California, United States. It was built by Caltech and the Jet Propulsion Laboratory and was intended to serve as a testbed for developing interferometric techniques to be used at the Keck Interferometer. It began operations in 1995 and achieved routine operations in 1998, producing more than 50 refereed papers in a variety of scientific journals covering topics from high precision astrometry to stellar masses, stellar diameters and shapes. PTI concluded operations in 2008 and has since been dismantled. PTI was notable for being equipped with a "dual-star" system, making it possible to simultaneously observe pairs of stars; this cancels some of the atmospheric effects of astronomical seeing and makes very high precision measurements possible. A groundbreaking study with the Palomar Testbed Interferometer revealed that the st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betelgeuse
Betelgeuse is a red supergiant of spectral type M1-2 and one of the largest stars visible to the naked eye. It is usually the tenth-brightest star in the night sky and, after Rigel, the second-brightest in the constellation of Orion. It is a distinctly reddish, semiregular variable star whose apparent magnitude, varying between +0.0 and +1.6, has the widest range displayed by any first-magnitude star. At near-infrared wavelengths, Betelgeuse is the brightest star in the night sky. Its Bayer designation is α Orionis, Latinised to Alpha Orionis and abbreviated Alpha Ori or α Ori. If it were at the center of our Solar System, its surface would lie beyond the asteroid belt and it would engulf the orbits of Mercury, Venus, Earth, and Mars. Nevertheless, there are several even larger stars in the Milky Way, including supergiants like Mu Cephei and the peculiar hypergiant, VY Canis Majoris. Calculations of Betelgeuse's mass range from slightly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antoine Émile Henry Labeyrie
Antoine Émile Henry Labeyrie (born 12 May 1943) is a French astronomer, who held the Observational astrophysics chair at the Collège de France between 1991 and 2014, where he is currently professor emeritus. He is working with the Hypertelescope Lise association, which aims to develop an extremely large astronomical interferometer with spherical geometry that might theoretically show features on Earth-like worlds around other suns, as its president. He is a member of the French Academy of Sciences in the Sciences of the Universe (''sciences de l'univers'') section. Between 1995 and 1999 he was director of the Haute-Provence Observatory. Labeyrie graduated from the "grande école" SupOptique (École supérieure d'optique). He invented speckle interferometry, and works with astronomical interferometers. Labeyrie concentrated particularly on the use of "diluted optics" beam combination or "densified pupils" of a similar type but larger scale than those Michelson used for meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Wilson Observatory
The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles. The observatory contains two historically important telescopes: the Hooker telescope, which was the largest aperture telescope in the world from its completion in 1917 to 1949, and the 60-inch telescope which was the largest operational telescope in the world when it was completed in 1908. It also contains the Snow solar telescope completed in 1905, the 60 foot (18 m) solar tower completed in 1908, the 150 foot (46 m) solar tower completed in 1912, and the CHARA array, built by Georgia State University, which became fully operational in 2004 and was the largest optical interferometer in the world at its completion. Due to the inversion layer that traps warm air and smog over Los Angeles, Mount Wilson has steadier air than any other location in Nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lens (optics)
A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), usually arranged along a common axis. Lenses are made from materials such as glass or plastic, and are ground and polished or molded to a desired shape. A lens can focus light to form an image, unlike a prism, which refracts light without focusing. Devices that similarly focus or disperse waves and radiation other than visible light are also called lenses, such as microwave lenses, electron lenses, acoustic lenses, or explosive lenses. Lenses are used in various imaging devices like telescopes, binoculars and cameras. They are also used as visual aids in glasses to correct defects of vision such as myopia and hypermetropia. History The word '' lens'' comes from '' lēns'', the Latin name of the lentil (a seed of a len ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Spatial Interferometer
The Infrared Spatial Interferometer (ISI) is an astronomical interferometer array of three telescopes operating in the mid- infrared. The telescopes are fully mobile and their current site on Mount Wilson allows for placements as far as apart, giving the resolution of a telescope of that diameter. The signals are converted to radio frequencies through heterodyne circuits and then combined electronically using techniques copied from radio astronomy. ISI is run by the University of California, Berkeley Space Sciences Laboratory. The longest () baseline provides a resolution of 0.003 arcsecond at a wavelength of 11 micrometres. On 9 July 2003, ISI recorded the first closure phase aperture synthesis Aperture synthesis or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection. At each separation and ... measurements in the mid in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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