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Giant Magellan Telescope
The Giant Magellan Telescope (GMT) is a ground-based extremely large telescope under construction, as part of the US Extremely Large Telescope Program (US-ELTP), . It will consist of seven 8.4 m (27.6 ft) diameter primary segments, that will observe optical and near infrared (320–25000 nm) light, with the resolving power of a 24.5 m (80.4 ft) primary mirror and collecting area equivalent to a 22.0 m (72.2 ft) one, which is about 368 square meters. The telescope is expected to have a resolving power 10 times that of the Hubble Space Telescope and four times that of the James Webb Space Telescope, although it will be unable to image in the same infrared frequencies available to telescopes in space. , six mirrors have been cast and the construction of the summit facility has begun. A total of seven primary mirrors are planned, but it will begin operation with four. The US$1 billion project is US-led in partnership with Australia, Brazil, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extremely Large Telescope
The Extremely Large Telescope (ELT) is an astronomical observatory currently under construction. When completed, it is planned to be the world's largest optical/near-infrared extremely large telescope. Part of the European Southern Observatory (ESO) agency, it is located on top of Cerro Armazones in the Atacama Desert of northern Chile. The design consists of a reflecting telescope with a segmented primary mirror and a diameter secondary mirror, and will be supported by adaptive optics, eight laser guide star units and multiple large science instruments. The observatory aims to gather 100 million times more light than the human eye, 13 times more light than the largest optical telescopes existing in 2014, and be able to correct for atmospheric distortion. It has around 256 times the light gathering area of the Hubble Space Telescope and, according to the ELT's specifications, would provide images 16 times sharper than those from Hubble. The project was originally called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steward Mirror Lab
Steward may refer to: Positions or roles * Steward (office), a representative of a monarch * Steward (Methodism), a leader in a congregation and/or district * Steward, a person responsible for supplies of food to a college, club, or other institution * Communion steward, a position in the local church responsible for the distribution of the Eucharistic elements * Horse show steward * Steward, an official in horse, greyhound racing or car racing * Steward, another term for majordomo * Steward, an older term for a flight attendant * A member of the Steward's Department of a ship, responsible for preparation of food or caring for living quarters * Steward, United States Navy rate prior to 1975, now Culinary Specialist (US Navy) * Union steward, a labor union official, also known as a shop steward * Wine steward or sommelier * Steward, a person who assists with crowd control * Steward, a junior officer of a Masonic Lodge People * Steward (surname) * Steward Ceus (born 1987), foo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altazimuth Mount
An altazimuth mount or alt-azimuth mount is a simple two-axis mount for supporting and rotating an instrument about two perpendicular axes – one vertical and the other horizontal. Rotation about the vertical axis varies the azimuth (compass bearing) of the pointing direction of the instrument. Rotation about the horizontal axis varies the altitude angle (angle of elevation) of the pointing direction. These mounts are used, for example, with telescopes, cameras, radio antennas, heliostat mirrors, solar panels, and guns and similar weapons. Several names are given to this kind of mount, including altitude-azimuth, azimuth-elevation and various abbreviations thereof. A gun turret is essentially an alt-azimuth mount for a gun, and a standard camera tripod is an alt-azimuth mount as well. Astronomical telescope altazimuth mounts When used as an astronomical telescope mount, the biggest advantage of an alt-azimuth mount is the simplicity of its mechanical design. The primary disadv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Resolution
Optical resolution describes the ability of an imaging system to resolve detail, in the object that is being imaged. An imaging system may have many individual components, including one or more lenses, and/or recording and display components. Each of these contributes (given suitable design, and adequate alignment) to the optical resolution of the system; the environment in which the imaging is done often is a further important factor. Lateral resolution Resolution depends on the distance between two distinguishable radiating points. The sections below describe the theoretical estimates of resolution, but the real values may differ. The results below are based on mathematical models of Airy discs, which assumes an adequate level of contrast. In low-contrast systems, the resolution may be much lower than predicted by the theory outlined below. Real optical systems are complex, and practical difficulties often increase the distance between distinguishable point sources. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Astronomical Instrumentation
The ''Journal of Astronomical Instrumentation'' is a quarterly peer-reviewed scientific journal that covers astronomical instruments and its various components being proposed, developed, under construction, and in use. The journal focuses on astronomical instrumentation topics in all wavebands (radio wave to gamma ray) and includes the disciplines of heliophysics, space weather, lunar and planetary science, exoplanet exploration, and astroparticle observation (cosmic rays, cosmic neutrinos, etc.). It was established in 2012 and is published by World Scientific. The journal occasionally publishes thematic issues on specific topics or projects. Abstracting and indexing The journal is abstracted and indexed in: * Astrophysics Data System * EBSCO databases * Emerging Sources Citation Index * InfoTrac databases * INSPIRE-HEP * Scopus Scopus is Elsevier's abstract and citation database launched in 2004. Scopus covers nearly 36,377 titles (22,794 active titles and 13,583 inactive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptive Optics
Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of incoming wavefront distortions by deforming a mirror in order to compensate for the distortion. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, in microscopy, optical fabrication and in retinal imaging systems to reduce optical aberrations. Adaptive optics works by measuring the distortions in a wavefront and compensating for them with a device that corrects those errors such as a deformable mirror or a liquid crystal array. Adaptive optics should not be confused with active optics, which works on a longer timescale to correct the primary mirror geometry. Other methods can achieve resolving power exceeding the limit imposed by atmospheric distortion, such as speckle imaging, aperture synthesis, and lucky imaging, or by moving outside the atmosphere with space telescopes, such as the Hubble Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gregorian Telescope
The Gregorian telescope is a type of reflecting telescope designed by Scottish mathematician and astronomer James Gregory in the 17th century, and first built in 1673 by Robert Hooke. James Gregory was a contemporary of Isaac Newton. Both often worked simultaneously on similar projects. Gregory's design was published in 1663 and pre-dates the first practical reflecting telescope, the Newtonian telescope, built by Sir Isaac Newton in 1668."Isaac Newton: adventurer in thought", by Alfred Rupert Hallpage 67 However, Gregory's design was only a theoretical description, and he never actually constructed the telescope. It was not successfully built until five years after Newton's first reflecting telescope. History The Gregorian telescope is named after the James Gregory design, which appeared in his 1663 publication (The Advance of Optics). Similar theoretical designs have been found in the writings of Bonaventura Cavalieri ( (On Burning Mirrors), 1632) and Marin Mersenne (, 1636). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Ratio
In optics, the f-number of an optical system such as a camera lens is the ratio of the system's focal length to the diameter of the entrance pupil ("clear aperture").Smith, Warren ''Modern Optical Engineering'', 4th Ed., 2007 McGraw-Hill Professional, p. 183. It is also known as the focal ratio, f-ratio, or f-stop, and is very important in photography. It is a dimensionless number that is a quantitative measure of lens speed; increasing the f-number is referred to as ''stopping down''. The f-number is commonly indicated using a lower-case hooked f with the format ''N'', where ''N'' is the f-number. The f-number is the reciprocal of the relative aperture (the aperture diameter divided by focal length). Notation The f-number is given by: N = \frac \ where f is the focal length, and D is the diameter of the entrance pupil (''effective aperture''). It is customary to write f-numbers preceded by "", which forms a mathematical expression of the entrance pupil diameter i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohara Corporation
is a Japanese global glass manufacturing company. The company is headquartered in Sagamihara with subsidiaries in a number of countries, including Japan, the United States, Germany, Hong Kong, Malaysia, Taiwan, and China, with Ohara Corporation being the U.S. subsidiary of the Ohara Group. Ohara manufactures glasses since 1935, the year of its founding. Their web site lists areas of specialization, including: * Optical Glass * Polished Substates * Fused Silica and Quartz * IR Materials and Optical Crystals * Low Expansion Glass * Glass Ceramics * Measurement Services Optical glass Among other things, Ohara is a major supplier of optical glass. Lens design programs will typically include glasses in the Ohara catalog among their stock material choices, along with, for example, glasses in the Schott catalog. On their website, Ohara describes a line of more than 130 environmentally safe glasses, produced without lead and arsenic. They produce more than 300 tons of optical glass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borosilicate Glass
Borosilicate glass is a type of glass with silica and boron trioxide as the main glass-forming constituents. Borosilicate glasses are known for having very low coefficients of thermal expansion (≈3 × 10−6 K−1 at 20 °C), making them more resistant to thermal shock than any other common glass. Such glass is subjected to less thermal stress and can withstand temperature differentials without fracturing of about . It is commonly used for the construction of reagent bottles and flasks as well as lighting, electronics, and cookware. Borosilicate glass is sold under various trade names, including Borosil, Duran, Pyrex, Glassco, Supertek, Suprax, Simax, Bellco, Marinex (Brazil), BSA 60, BSC 51 (by NIPRO), Heatex, Endural, Schott, Refmex, Kimax, Gemstone Well, and MG (India). Single ended self-starting lamps are insulated with a mica disc and contained in a borosilicate glass gas discharge tube (arc tube) and a metal cap. They include the sodium-vapor lamp tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotating Furnace
A rotating furnace is a device for making solid objects which have concave surfaces that are segments of axially symmetrical paraboloids. Usually, the objects are made of glass. The furnace makes use of the fact, which was known already to Newton, that the centrifugal-force-induced shape of the top surface of a spinning liquid is a concave paraboloid, identical to the shape of a reflecting telescope's primary focusing mirror. Paraboloids can be used in various ways, including (after being silvered) as primary mirrors in reflecting telescopes and solar cookers. Design The furnace includes a mechanism that rotates an open-topped container at constant speed around a vertical axis. A quantity of glass sufficient to make the mirror is placed in the container, heated until it is completely molten, and then allowed to cool while continuing to rotate until it has completely solidified. When the glass is solid, the rotation is stopped and the paraboloidal shape of its top surface is pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
