1.
Lowell Observatory
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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, in 2011, the Observatory was named one of The Worlds 100 Most Important Places by TIME. It was at the Lowell Observatory that the dwarf planet Pluto was discovered in 1930 by Clyde Tombaugh, the Observatorys original 61-centimeter Alvan Clark & Sons Telescope is still in use today for public education. It was founded by astronomer Percival Lowell of Bostons well-known Lowell family and is overseen by a sole trustee, the first trustee was Lowells third cousin Guy Lowell. Percivals nephew Roger Putnam served from 1927–1967, followed by Rogers son Michael, Michaels brother William Lowell Putnam III, the observatory operates several telescopes at three locations in the Flagstaff area. The telescope, built in 1896 for $20,000, was assembled in Boston by Alvan Clark & Sons, also located on the Mars Hill campus is the 33-centimeter Pluto Discovery Telescope, used by Clyde Tombaugh in 1930 to discover the dwarf planet Pluto. Lowell is a partner with the United States Naval Observatory and Naval Research Laboratory in the Navy Precision Optical Interferometer also located at that site, the Observatory also operates smaller research telescopes at its historic site on Mars Hill and in Australia and Chile. Past Anderson Mesa, on the peak of Happy Jack, Lowell Observatory has also built and is commissioning the 4. 28-meter Discovery Channel Telescope in partnership with Discovery Communications, Inc. Aside from the array of research and discoveries listed below. When Harold L. Johnson took over as the director in 1952, in 1953, the current 53 cm telescope was erected. Beginning in 1954, this telescope began monitoring the brightness of two planets, and comparing these measurements with a reference set of sunlike stars. Lowell Observatory is building a major new reflecting telescope in partnership with Discovery Communications, located near Happy Jack, the primary mirror of the Discovery Channel Telescope will be 4.28 m in diameter. It will be notable for its uncommon meniscus design for such a large mirror. This mirror was ground and polished into its parabolic shape at the Optical Fabrication, Lowell Observatorys astronomers conduct research on a wide range of solar system and astrophysical topics using ground-based, airborne, and space-based telescopes. In addition, the Observatory staff designs and builds custom instrumentation for use on Lowells telescopes, for example, Lowell staff built a sophisticated high-speed camera for use on the Stratospheric Observatory for Infrared Astronomy. SOFIA is a joint project of the United States and German space agencies, Lowell, Percival, Pickering, W. H. and the founding of the Lowell Observatory. National Historic Landmarks Program, Lowell Observatory+ Historic American Buildings Survey No, aZ-206, Lowell Observatory,1400 West Mars Hill Road, Flagstaff, Coconino County, AZ HABS No. AZ-206-A, Lowell Observatory, Slipher Building HABS No, aZ-206-B, Lowell Observatory, Clark Dome HABS No
2.
United States Naval Observatory
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The USNO operates the Master Clock, which provides precise time to the GPS satellite constellation run by the United States Air Force. The USNO performs radio VLBI-based positions of quasars with numerous global collaborators, aside from its scientific mission, a house located within the Naval Observatory complex serves as the official residence of the Vice President of the United States. President John Quincy Adams, who in 1825 signed the bill for the creation of an observatory just before leaving presidential office, had intended for it to be called the National Observatory. The names National Observatory and Naval Observatory were both used for 10 years, until a ruling was passed to use the latter. Adams had made protracted efforts to bring astronomy to a level at that time. He spent many nights at the observatory, watching and charting the stars, established by the order of the United States Secretary of the Navy John Branch on 6 December 1830 as the Depot of Charts and Instruments, the Observatory rose from humble beginnings. Placed under the command of Lieutenant Louis M. Goldsborough, with an budget of $330, its primary function was the restoration, repair. It was made into an observatory in 1842 via a federal law. Lieutenant James Melville Gilliss was put in charge of obtaining the instruments needed, lt. Gilliss visited the principal observatories of Europe with the mission to purchase telescopes and scientific devices and books. The observatorys primary mission was to care for the United States Navys marine chronometers, charts and it calibrated ships chronometers by timing the transit of stars across the meridian. These facilities were listed on the National Register of Historic Places in 2017, the first superintendent was Navy Commander Matthew Fontaine Maury. Maury had the worlds first vulcanized time ball, created to his specifications by Charles Goodyear for the U. S. Observatory and it was the first time ball in the United States, being placed into service in 1845, and the 12th in the world. Maury kept accurate time by the stars and planets, the time ball was dropped every day except Sunday precisely at the astronomically defined moment of Mean Solar Noon, enabling all ships and civilians to know the exact time. Time was also sold to the railroads and was used in conjunction with railroad chronometers to schedule American rail transport, early in the 20th century, the Arlington Time Signal broadcast this service to wireless receivers. In 1849 the Nautical Almanac Office was established in Cambridge, Massachusetts as a separate organization and it was moved to Washington, D. C. in 1866, colocating with the U. S. Naval Observatory in 1893. On September 20,1894, the NAO became a branch of USNO, the astronomical measurements taken of the transit of Venus by a number of countries since 1639 resulted in a progressively more accurate definition of the AU. Relying heavily on methods, the naval observers returned 350 photographic plates in 1874. This calculated distance was a significant improvement over several previous estimates, the telescope used for the discovery of the Moons of Mars was the 26-inch refractor, then located at Foggy Bottom
3.
Coconino County, Arizona
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Coconino County is a county located in the north central part of the U. S. state of Arizona. The population was 134,421 at the 2010 census, the county takes its name from Cohonino, a name applied to the Havasupai. It is the second-largest county by area in the contiguous United States, behind San Bernardino County, California, Coconino County comprises the Flagstaff, AZ Metropolitan Statistical Area. Coconino County contains Grand Canyon National Park, the Havasupai Nation, and parts of the Navajo Nation, Hualapai Nation, and Hopi Nation. It has a relatively large Native American population at nearly 30% of the total population, being mostly Navajo with smaller numbers of Havasupai, Hopi. The county was the setting for George Herrimans early-20th-century Krazy Kat comic strip, after the building of the Atlantic & Pacific Railroad in 1883 the region of northern Yavapai County began experiencing rapid growth. The people of the northern reaches had tired of the rigors of travelling all the way to Prescott for county business and they also believed that they were a significant enough entity that they should have their own county jurisdiction. Therefore, they decided in 1887 to petition for secession from Yavapai and they remained part of Yavapai, however, until 1891 when Coconino County was formed and its seat declared to be Flagstaff. According to the U. S. Census Bureau, the county has an area of 18,661 square miles. It is the largest county by area in Arizona and the second-largest county in the United States after San Bernardino County in California. It has more area than each of the following U. S. states, Connecticut, Delaware, Hawaii, Maryland, Massachusetts, New Hampshire, New Jersey, Rhode Island. The highest natural point in the county, as well as the state, is Humphreys Peak at 12,637 feet or 3,852 metres. The Barringer Meteor Crater is located in Coconino County, the Havasupai Reservation is the only one that lies entirely within the countys borders. As of the 2000 census, there were 116,320 people,40,448 households, the population density was 6 people per square mile. There were 53,443 housing units at a density of 3 per square mile. 10. 94% of the population were Hispanic or Latino of any race,18. 59% reported speaking Navajo at home, while 6. 58% speak Spanish. 22. 10% of all households were made up of individuals and 4. 50% had someone living alone who was 65 years of age or older, the average household size was 2.80 and the average family size was 3.36. In the county, the population was out with 28. 70% under the age of 18,14. 40% from 18 to 24,29. 20% from 25 to 44,20. 70% from 45 to 64
4.
Flagstaff, Arizona
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Flagstaff is a city in northern Arizona, in the southwestern United States. In 2015, the estimated population was 70,320. Flagstaffs combined metropolitan area has an population of 139,097. It is the county seat of Coconino County, the city is named after a ponderosa pine flagpole made by a scouting party from Boston to celebrate the United States Centennial on July 4,1876. Flagstaff lies near the edge of the Colorado Plateau, along the western side of the largest contiguous Ponderosa Pine forest in the continental United States. Flagstaff is located adjacent to Mount Elden, just south of the San Francisco Peaks, humphreys Peak, the highest point in Arizona at 12,633 feet, is located about 10 miles north of Flagstaff in Kachina Peaks Wilderness. Flagstaffs early economy was based on the lumber, railroad, Flagstaff has a strong tourism sector, due to its proximity to Grand Canyon National Park, Oak Creek Canyon, the Arizona Snowbowl, Meteor Crater, and historic Route 66. The city is also a center for medical device manufacturing, since Flagstaff is home to W. L. Gore, there exist several stories and legends regarding the origin of the citys name. It is said that, because of the flag that was raised, the first permanent settlement was in 1876, when Thomas F. McMillan built a cabin at the base of Mars Hill on the west side of town. During the 1880s, Flagstaff began to grow, opening its first post office, the early economy was based on timber, sheep, and cattle. By 1886, Flagstaff was the largest city on the line between Albuquerque and the west coast of the United States. A circa 1900 diary entry by journalist Sharlot Hall described the houses in the city at the time as a third rate mining camp, with unkempt air, in 1894, Massachusetts astronomer Percival Lowell hired A. E. Douglass to scout an ideal site for a new observatory. Douglass, impressed by Flagstaffs elevation, named it as a location for the now famous Lowell Observatory, saying, other things being equal. Two years later, the specially designed 24-inch Clark telescope that Lowell had ordered was installed, in 1930, Pluto was discovered using one of the observatorys telescopes. During the Apollo program in the 1960s, the Clark Telescope was used to map the moon for the lunar expeditions, in homage to the citys importance in the field of astronomy, asteroid 2118 Flagstaff is named for the city, and 6582 Flagsymphony for the Flagstaff Symphony Orchestra. The Northern Arizona Normal School was established in 1899, renamed Northern Arizona University in 1966, Flagstaffs cultural history received a significant boost on April 11,1899, when the Flagstaff Symphony made its concert debut at Babbitts Opera House. The orchestra continues today as the Flagstaff Symphony Orchestra, with its venue at the Ardrey Auditorium on the campus of Northern Arizona University. The city grew rapidly, primarily attributable to its location along the east–west transcontinental railroad line in the United States, in the 1880s, the railroads purchased land in the west from the federal government, which was then sold to individuals to help finance the railroad projects
5.
Geographic coordinate system
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A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are chosen such that one of the numbers represents a vertical position. A common choice of coordinates is latitude, longitude and elevation, to specify a location on a two-dimensional map requires a map projection. The invention of a coordinate system is generally credited to Eratosthenes of Cyrene. Ptolemy credited him with the adoption of longitude and latitude. Ptolemys 2nd-century Geography used the prime meridian but measured latitude from the equator instead. Mathematical cartography resumed in Europe following Maximus Planudes recovery of Ptolemys text a little before 1300, in 1884, the United States hosted the International Meridian Conference, attended by representatives from twenty-five nations. Twenty-two of them agreed to adopt the longitude of the Royal Observatory in Greenwich, the Dominican Republic voted against the motion, while France and Brazil abstained. France adopted Greenwich Mean Time in place of local determinations by the Paris Observatory in 1911, the latitude of a point on Earths surface is the angle between the equatorial plane and the straight line that passes through that point and through the center of the Earth. Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the equator, the north pole is 90° N, the south pole is 90° S. The 0° parallel of latitude is designated the equator, the plane of all geographic coordinate systems. The equator divides the globe into Northern and Southern Hemispheres, the longitude of a point on Earths surface is the angle east or west of a reference meridian to another meridian that passes through that point. All meridians are halves of great ellipses, which converge at the north and south poles, the prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side. The antipodal meridian of Greenwich is both 180°W and 180°E, the combination of these two components specifies the position of any location on the surface of Earth, without consideration of altitude or depth. The grid formed by lines of latitude and longitude is known as a graticule, the origin/zero point of this system is located in the Gulf of Guinea about 625 km south of Tema, Ghana. To completely specify a location of a feature on, in, or above Earth. Earth is not a sphere, but a shape approximating a biaxial ellipsoid. It is nearly spherical, but has an equatorial bulge making the radius at the equator about 0. 3% larger than the radius measured through the poles, the shorter axis approximately coincides with the axis of rotation
6.
Cassegrain reflector
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The Cassegrain reflector is a combination of a primary concave mirror and a secondary convex mirror, often used in optical telescopes and radio antennas. Alternatively, as in radio telescopes, the final focus may be in front of the primary. In an asymmetrical Cassegrain, the mirror may be tilted to avoid obscuration of the primary or to avoid the need for a hole in the primary mirror, the classic Cassegrain configuration uses a parabolic reflector as the primary while the secondary mirror is hyperbolic. Modern variants often have a primary for increased performance, or the primary and/or secondary are spherical or elliptical for ease of manufacturing. The Cassegrain reflector is named after a published reflecting telescope design that appeared in the April 25,1672 Journal des sçavans which has been attributed to Laurent Cassegrain. Similar designs using convex secondaries have been found in the Bonaventura Cavalieris 1632 writings describing burning mirrors, james Gregorys 1662 attempts to create a reflecting telescope included a Cassegrain configuration, judging by a convex secondary mirror found among his experiments. The Cassegrain design is used in catadioptric systems. The Classic Cassegrain has a primary mirror, and a hyperbolic secondary mirror that reflects the light back down through a hole in the primary. Folding the optics makes this a compact design, on smaller telescopes, and camera lenses, the secondary is often mounted on an optically flat, optically clear glass plate that closes the telescope tube. This support eliminates the diffraction effects caused by a straight-vaned support spider. The closed tube stays clean, and the primary is protected and it makes use of the special properties of parabolic and hyperbolic reflectors. A concave parabolic reflector will reflect all incoming light rays parallel to its axis of symmetry to a single point, a convex hyperbolic reflector has two foci and will reflect all light rays directed at one of its two foci towards its other focus. The parabolic mirror reflects parallel light rays entering the telescope to its focus, the hyperbolic mirror then reflects those light rays to its other focus, where the image is observed. The Ritchey-Chrétien is a specialized Cassegrain reflector which has two hyperbolic mirrors and it is free of coma and spherical aberration at a flat focal plane, making it well suited for wide field and photographic observations. It was invented by George Willis Ritchey and Henri Chrétien in the early 1910s and this design is very common in large professional research telescopes, including the Hubble Space Telescope, Keck Telescopes and VLT telescope, it is also found in high-grade amateur telescopes. Ingalls, the astronomy editor at the time. It uses a concave primary mirror and a convex spherical secondary. While this system is easier to polish than a classic Cassegrain or Ritchey-Chretien system, because this is less noticeable at longer focal ratios, Dall-Kirkhams are seldom faster than f/15
7.
Telescope
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A telescope is an optical instrument that aids in the observation of remote objects by collecting electromagnetic radiation. The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s and they found use in both terrestrial applications and astronomy. Within a few decades, the telescope was invented, which used mirrors to collect. In the 20th century many new types of telescopes were invented, including radio telescopes in the 1930s, 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 word telescope was coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galileis instruments presented at a banquet at the Accademia dei Lincei, in the Starry Messenger, Galileo had used the term perspicillum. The earliest recorded working telescopes were the telescopes that appeared in the Netherlands in 1608. Their development is credited to three individuals, Hans Lippershey and Zacharias Janssen, who were spectacle makers in Middelburg, Galileo heard about the Dutch telescope in June 1609, built his own within a month, and improved upon the design in the following year. Also in 1609, Thomas Harriot became the first person known to point a telescope skyward in order to make observations of a celestial object. The idea that the objective, or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope. The potential advantages of using parabolic mirrors—reduction of spherical aberration and no chromatic aberration—led to many proposed designs, in 1668, Isaac Newton built the first practical reflecting telescope, of a design which now bears his name, the Newtonian reflector. The invention of the lens in 1733 partially corrected color aberrations present in the simple lens and enabled the construction of shorter. The largest reflecting telescopes currently have objectives larger than 10 m, the 20th century also saw the development of telescopes that worked in a wide range of wavelengths from radio to gamma-rays. The first purpose built radio telescope went into operation in 1937, since then, a tremendous variety of complex astronomical instruments have been developed. The name telescope covers a range of instruments. Most detect electromagnetic radiation, but there are differences in how astronomers must go about collecting light in different frequency bands. The near-infrared can be collected much like light, however in the far-infrared and submillimetre range. For example, the James Clerk Maxwell Telescope observes from wavelengths from 3 μm to 2000 μm, on the other hand, the Spitzer Space Telescope, observing from about 3 μm to 180 μm uses a mirror. Also using reflecting optics, the Hubble Space Telescope with Wide Field Camera 3 can observe in the range from about 0.2 μm to 1.7 μm
8.
Reflecting telescope
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A reflecting telescope is an optical telescope which uses a single or combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century as an alternative to the telescope which. Although reflecting telescopes produce other types of aberrations, it is a design that allows for very large diameter objectives. Almost all of the telescopes used in astronomy research are reflectors. Reflecting telescopes come in many variations and may employ extra optical elements to improve image quality or place the image in a mechanically advantageous position. Since reflecting telescopes use mirrors, the design is referred to as a catoptric telescope. The idea that curved mirrors behave like lenses dates back at least to Alhazens 11th century treatise on optics, the potential advantages of using parabolic mirrors, primarily reduction of spherical aberration with no chromatic aberration, led to many proposed designs for reflecting telescopes. The most notable being James Gregory, who published a design for a ‘reflecting’ telescope in 1663. It would be ten years, before the experimental scientist Robert Hooke was able to build this type of telescope, Isaac Newton has been generally credited with building the first reflecting telescope in 1668. It used a spherically ground metal primary mirror and a diagonal mirror in an optical configuration that has come to be known as the Newtonian telescope. A curved primary mirror is the reflector telescopes basic optical element that creates an image at the focal plane, the distance from the mirror to the focal plane is called the focal length. The primary mirror in most modern telescopes is composed of a glass cylinder whose front surface has been ground to a spherical or parabolic shape. A thin layer of aluminum is deposited onto the mirror. Some telescopes use primary mirrors which are made differently, molten glass is rotated to make its surface paraboloidal, and is kept rotating while it cools and solidifies. The resulting mirror shape approximates a desired paraboloid shape that requires grinding and polishing to reach the exact figure needed. Reflecting telescopes, just like any other system, do not produce perfect images. The use of mirrors avoids chromatic aberration but they produce other types of aberrations, to avoid this problem most reflecting telescopes use parabolic shaped mirrors, a shape that can focus all the light to a common focus. Field curvature - The best image plane is in general curved and it is sometimes corrected by a field flattening lens
9.
Navy Precision Optical Interferometer
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The facility is located at Lowells Anderson Mesa Station on Anderson Mesa about 25 kilometers southeast of Flagstaff, Arizona. Until November 2011, the facility was known as the Navy Prototype Optical Interferometer, the NPOI project was initiated by the United States Naval Observatory in 1987. Lowell joined the project the year when the USNO decided to build the NPOI at Anderson Mesa. The first phase of construction was completed in 1994, which allowed the interferometer to see its first fringes, or light combined from multiple sources, the Navy began regular science operations in 1997. The NPOI has been upgraded and expanded since then, and has been operational for a decade. The workings of NPOI as an interferometer, are described at Scholarpedia. The NPOI is an astronomical interferometer laid out in a three-arm Y configuration, there are two types of stations that can be used in the NPOI. Astrometric stations, used to measure the positions of celestial objects very accurately, are fixed units placed 21 meters apart, with one on each arm and one at the center. Imaging stations can be moved to one of nine positions on each arm, light from either type of station is first directed into the feed system, which consists of long pipes which have been evacuated of all air. They lead to a switchyard of mirrors, where the light is directed into the six Long Delay Lines, the light is then sent into the Beam Combining Facility, where it enters the Fast Delay Lines. This third set of evacuated pipes contains mechanisms that move mirrors back and these compensate for the movement of the mirrors as they track an object across the sky, and for other effects. Finally, the leaves the pipes inside the BCF and goes to the Beam Combining Table. Both types of station have three elements, a siderostat, a Wide Angle Star Acquisition camera, and a Narrow Angle Tracking camera, the first is a precisely-ground flat mirror 50 cm in diameter. The WASA cameras control the aiming of the mirror at the celestial target, the reflected light from the siderostat is directed through a telescope which narrows the beam down to the diameter of the pipes, which is 12 cm. The light then hits the mirror of the NAT, which compensates for atmospheric effects and directs the light into the feed system. They were originally intended to be outrigger telescopes for the W. M. Keck Observatory in Hawaii, three telescopes are being prepared for near-immediate installation, while the fourth is currently at Mount Stromlo Observatory in Australia and will be incorporated at some point in the future. The new telescopes will help with faint object imaging and improved absolute astrometry, NOFS operates and leads the science for the Navy Precision Optical Interferometer, as noted, in collaboration with Lowell Observatory and the Naval Research Laboratory at Anderson Mesa. NOFS funds all principal operations, and from this contracts Lowell Observatory to maintain the Anderson Mesa facility, when complete by 2013, NPOI will run the longest baseline interferometer in the world
