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Expres Magazin
The EXtreme PREcision Spectrograph (EXPRES) is an optical fiber fed echelle instrument designed and built at the Yale Exoplanet Laboratory to be installed on the 4.3-meter Lowell Discovery Telescope operated by Lowell Observatory. It has a goal to achieve 10 cm/s radial velocity precision. It uses a laser frequency comb In optics, a frequency comb is a laser source whose spectrum consists of a series of discrete, equally spaced frequency lines. Frequency combs can be generated by a number of mechanisms, including periodic modulation (in amplitude and/or phase) of a ... (LFC) to calibrate the primary wavelength for EXPRES. EXPRES: A Next Generation RV Spectrograph in the Search for Earth-like Worlds See also * ESPRESSO spectrograph * HARPS3 References Astronomical instruments Telescope instruments Exoplanet search projects Spectrographs {{astrobiology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Fiber
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss; in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer. Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are also used for a variety of other applications, some of them being fiber optic sensors and fiber lasers. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echelle Grating
An echelle grating (from French ''échelle'', meaning "ladder") is a type of diffraction grating characterised by a relatively low groove density, but a groove shape which is optimized for use at high incidence angles and therefore in high diffraction orders. Higher diffraction orders allow for increased dispersion (spacing) of spectral features at the detector, enabling increased differentiation of these features. Echelle gratings are, like other types of diffraction gratings, used in spectrometers and similar instruments. They are most useful in cross-dispersed high resolution spectrographs, such as HARPS, PARAS, and numerous other astronomical instruments. History The concept of a coarsely-ruled grating used at grazing angles was discovered by Albert Michelson in 1898, where he referred to it as an "echelon". However, it was not until 1923 that echelle spectrometers began to take on their characteristic form, in which the high-resolution grating is used in tandem with a cro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lowell Discovery Telescope
The Lowell Discovery Telescope (LDT), formerly the Discovery Channel Telescope (DCT), is a aperture telescope owned and operated by Lowell Observatory. The LDT was built at a dark sky site in the Coconino National Forest near Happy Jack, Arizona. Happy Jack is located at an elevation of and is approximately south-south-east of Flagstaff. The project was initially a partnership between Discovery Communications and Lowell Observatory. The research partnerships have been extended to include Boston University, The University of Maryland, The University of Toledo, and Northern Arizona University. The telescope cost $53 million. It significantly augments Lowell Observatory's observational capability and enables pioneering studies in a number of important research areas. With its 4-meter class primary mirror, the Lowell Discovery Telescope is the fifth largest telescope in the continental United States (). Final construction of the telescope was completed by February 2012 and firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lowell Observatory
Lowell Observatory is an astronomical observatory in Flagstaff, Arizona, United States. Lowell Observatory was established in 1894, placing it among the oldest observatories in the United States, and was designated a National Historic Landmark in 1965. and In 2011, the Observatory was named one of "The World's 100 Most Important Places" by Time Magazine. It was at the Lowell Observatory that the dwarf planet Pluto was discovered in 1930 by Clyde Tombaugh. The observatory was founded by astronomer Percival Lowell of Boston's Lowell family and is overseen by a sole trustee, a position historically handed down through the family. The first trustee was Lowell's third cousin Guy Lowell (1916–1927). Percival's nephew Roger Putnam served from 1927 to 1967, followed by Roger's son Michael (1967–1987), Michael's brother William Lowell Putnam III (1987–2013), and current trustee W. Lowell Putnam. Multiple astronauts attended the Lowell Observatory in 1963 while the moon was being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Comb
In optics, a frequency comb is a laser source whose spectrum consists of a series of discrete, equally spaced frequency lines. Frequency combs can be generated by a number of mechanisms, including periodic modulation (in amplitude and/or phase) of a continuous-wave laser, four-wave mixing in nonlinear media, or stabilization of the pulse train generated by a mode-locked laser. Much work has been devoted to this last mechanism, which was developed around the turn of the 21st century and ultimately led to one half of the Nobel Prize in Physics being shared by John L. Hall and Theodor W. Hänsch in 2005. The frequency domain representation of a perfect frequency comb is a series of delta functions spaced according to : f_n = f_0 + n\,f_r, where n is an integer, f_r is the comb tooth spacing (equal to the mode-locked laser's repetition rate or, alternatively, the modulation frequency), and f_0 is the carrier offset frequency, which is less than f_r. Combs spanning an octave in freq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ESPRESSO
Espresso (, ) is a coffee-brewing method of Italian origin, in which a small amount of nearly boiling water (about ) is forced under of pressure through finely-ground coffee beans. Espresso can be made with a wide variety of coffee beans and roast degrees. Espresso is the most common way of making coffee in southern Europe, especially in Italy, France, Spain, and Portugal. It is also popular in Switzerland, Croatia, Bosnia and Herzegovina, Bulgaria, Greece, South Africa, the United Kingdom, the United States, Canada, Australia and New Zealand. Espresso is generally thicker than coffee brewed by other methods, with a viscosity similar to that of warm honey. This is due to the higher concentration of suspended and dissolved solids, and the ''crema'' on top (a foam with a creamy consistency). As a result of the pressurized brewing process, the flavors and chemicals in a typical cup of espresso are very concentrated. Espresso has more caffeine per unit volume than most coffee be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isaac Newton Telescope
The Isaac Newton Telescope or INT is a 2.54 m (100 in) optical telescope run by the Isaac Newton Group of Telescopes at Roque de los Muchachos Observatory on La Palma in the Canary Islands since 1984. Originally the INT was situated at Herstmonceux Castle in Sussex, England, which was the site of the Royal Greenwich Observatory after it moved away from Greenwich due to light pollution. It was inaugurated in 1967 by Queen Elizabeth II. Herstmonceux suffered from poor weather, and the advent of mass air travel made it plausible for UK astronomers to run an overseas observatory. In 1979, the INT was shipped to La Palma, where it has remained ever since. It saw its second first light in 1984, with a video camera. A major change was the mirror was now made of the new type Zerodur glass, as compared to the old mirror's Pyrex glass. Today, it is used mostly with the Wide Field Camera (WFC), a four CCD instrument with a field of view of 0.56×0.56 square degrees which was commis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Instruments
Astronomical instruments include: *Alidade * Armillary sphere *Astrarium * Astrolabe *Astronomical clock *the Antikythera mechanism, an astronomical clock *Blink comparator *Bolometer *the Canterbury Astrolabe Quadrant *Celatone *Celestial sphere *Charge-coupled device *Computers *CMOS sensor *Coronagraph *Cosmolabe *Dioptra *Equatorial ring *Equatorium * Gnomon * Inclinometer * Interferometer * Kamal *Meridian circle * Microchannel plate detector *Mural instrument *Nebra sky disk *Nocturnal * Octant *Optical spectrometer, a.k.a., Spectrograph *Orrery *Photographic plate *Photometer *Planisphere *the Prague astronomical clock * Quadrant *Reticle *Radio plate *Retroreflector * Scaphe * Sextant * Starshade *Space telescope *Spectrometers *Sundial *Telescope *Torquetum * Triquetrum *Zenith telescope See also *Astronomy *Outline of astronomy *Surveying instrument *Measurement instrument {{DEFAULTSORT:Astronomical instruments Instruments Instrument may refer to: Science and te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescope Instruments
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects, the word ''telescope'' now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors. The first known practical telescopes were refracting telescopes with glass lenses and were invented in the Netherlands at the beginning of the 17th century. They were used for both terrestrial applications and astronomy. The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope. In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. Etymology The word ''telescope'' was coi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanet Search Projects
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. About 1 in 5 Sun-like starsFor the purpose of this 1 in 5 statistic, "Sun-like" means G-type star. Data for Sun-like stars was not available so this statistic is an extrapolation from data about K-type stars. have an "Earth-sized"For the purpose of this 1 in 5 statistic, Earth-sized means 1–2 Earth radii. planet in the habitable zone. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
