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Comet Hyakutake
Comet Hyakutake (Astronomical naming conventions#Comets, formally designated C/1996 B2) is a comet discovered on 31 January 1996. It was dubbed the Great Comet of 1996; its passage to within of the Earth on 25 March was one of the closest cometary approaches of the previous 200 years. Reaching an apparent visual magnitude of zero and spanning nearly 80°, Hyakutake appeared very bright in the night sky and was widely seen around the world. The comet temporarily upstaged the much anticipated Comet Hale–Bopp, which was approaching the inner Solar System at the time. Hyakutake is a Comet#Orbital characteristics, long-period comet that passed perihelion on 1 May 1996. Before its most recent passage through the Solar System, its orbital period was about 17,000 years, but the gravitational Perturbation (astronomy), perturbation of the giant planets has increased this period to 70,000 years. This is the first comet to have an X-ray emission detected, which is most likely th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yuji Hyakutake
was a Japanese amateur astronomer who discovered Comet C/1996 B2, also known as Comet Hyakutake on January 31, 1996, while using 25×150 binoculars. Hyakutake graduated from the Kyushu Sangyo University as a photography major and started working at a newspaper in Fukuoka. He first became interested in astronomy after seeing Comet Ikeya–Seki in 1965. He began searching for comets in 1989. In 1993, he moved to Hayato for because “the skies were much clearer there” and so he could better continue his search for comets. His first discovery was Comet C/1995 Y1, on December 26, 1995. Hyakutake discovered C/1996 B2 while looking for C/1995 Y1, a comet he had discovered a few weeks before. He died in Kokubu, Kagoshima, in 2002 at age 51 of an aneurysm which had led to internal bleeding. Asteroid 7291 Hyakutake 7 (seven) is the natural number following 6 and preceding 8. It is the only prime number preceding a cube. As an early prime number in the series of positive i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulysses Probe
''Ulysses'' ( , ) was a robotic space probe whose primary mission was to orbit the Sun and study it at all latitudes. It was launched in 1990 and made three "fast latitude scans" of the Sun in 1994/1995, 2000/2001, and 2007/2008. In addition, the probe studied several comets. ''Ulysses'' was a joint venture of the European Space Agency (ESA) and the United States' National Aeronautics and Space Administration (NASA), under leadership of ESA with participation from Canada's National Research Council. The last day for mission operations on ''Ulysses'' was 30 June 2009. To study the Sun at all latitudes, the probe needed to change its orbital inclination and leave the plane of the Solar System. To change the orbital inclination of a spacecraft to about 80° requires a large change in heliocentric velocity, the energy to achieve which far exceeded the capabilities of any launch vehicle. To reach the desired orbit around the Sun, the mission's planners chose a gravity assist ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precovery
In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of a celestial object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This happens most often with minor planets, but sometimes a comet, a dwarf planet, a natural satellite, or a star is found in old archived images; even exoplanet precovery observations have been obtained. "Precovery" refers to a pre-discovery image; "recovery" refers to imaging of a body which was lost to our view (as behind the Sun), but is now visible again ''(also see lost minor planet and lost comet)''. Orbit determination requires measuring an object's position on multiple occasions. The longer the interval between observations, the more accurately the orbit can be calculated; however, for a newly discovered object, only a few days' or weeks' worth of measured positions may be available, sufficient only for a preliminary (imprecise) orbit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Unit
The astronomical unit (symbol: au or AU) is a unit of length defined to be exactly equal to . Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its modern redefinition in 2012. The astronomical unit is used primarily for measuring distances within the Solar System or around other stars. It is also a fundamental component in the definition of another unit of astronomical length, the parsec. One au is approximately equivalent to 499 light-seconds. History of symbol usage A variety of unit symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union (IAU) had used the symbol ''A'' to denote a length equal to the astronomical unit. In the astronomical literature, the symbol AU is common. In 2006, the International Bureau of Weights and Measures (BIPM) had recommended ua as the symbol for the unit, from the French ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcminute
A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth's circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (abbreviated as arcsec), or arc second, denoted by the symbol , is a unit of angular measurement equal to of a minute of arc, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal (base 60) subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying, and marksmanship. To express even smaller angles, standard SI prefixes can be employed; the milliarcse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), extinction of the object's light caused by interstellar dust along the sightline, line of sight to the observer. Unless stated otherwise, the word ''magnitude'' in astronomy usually refers to a celestial object's apparent magnitude. The magnitude scale likely dates to before the ancient Ancient Greek astronomy#Astronomy in the Greco-Roman and Late Antique eras, Roman astronomer Ptolemy, Claudius Ptolemy, whose Star catalogue, star catalog popularized the system by listing stars from First-magnitude star, 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined to closely match this historical system by Norman Robert Pogson, Norman Pogson in 1856. The scale is reverse logarithmic scale, logarithmic: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Astronomical Observatory Of Japan
The (NAOJ) is an astronomy, astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii and Chile. It was established in 1988 as an amalgamation of three existing research organizations - the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University. In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences, Japan, National Institutes of Natural Sciences. Facilities ;Mitaka Campus (Mitaka, Tokyo. ) :The Headquarters, Astronomy Data Center, Advanced Technology Center, Public Relations Center :Solar Flare Telescope, Sunspot Telescope, TAMA 300 gravitational wave detector :Tokyo Photoelectric Meridian Circle :Historical instruments: Solar Tower Telescope, 65cm refractor dome, 20cm refractor dome ;Nobeyama Radio Observatory (Minamimaki, Nagano. ) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naked Eye
Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnification, magnifying, Optical telescope#Light-gathering power, light-collecting optical instrument, such as a telescope or microscope, or eye protection. In astronomy, the naked eye may be used to observe celestial events and astronomical object, objects visible without equipment, such as conjunction (astronomy), conjunctions, passing comets, meteor showers, and the brightest asteroids, including 4 Vesta. Sky lore and various tests demonstrate an impressive variety of phenomena visible to the unaided eye. Basic properties Some basic properties of the human eye are: *Quick autofocus from distances of 25 cm (young people) to 50 cm (most people 50 years and older) to infinity. *Angular resolution: about 1 arcminute, approximately 0.017° or 0.0003 radians, which corresponds to 0.3 m at a 1 km distance. *Field of view (FOV): simultaneous visual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objective Lens
In optical engineering, an objective is an optical element that gathers light from an object being observed and focuses the light rays from it to produce a real image of the object. Objectives can be a single lens or mirror, or combinations of several optical elements. They are used in microscopes, binoculars, telescopes, cameras, slide projectors, CD players and many other optical instruments. Objectives are also called object lenses, object glasses, or objective glasses. Microscope objectives The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes to a focus inside the microscope tube. The objective itself is usually a cylinder containing one or more lenses that are typically made of glass; its function is to collect light from the sample. Magnification One of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binoculars
Binoculars or field glasses are two refracting telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. Most binoculars are sized to be held using both hands, although sizes vary widely from opera glasses to large pedestal-mounted military models. Unlike a (monocular) telescope, binoculars give users a stereopsis, three-dimensional image: each eyepiece presents a slightly different image to each of the viewer's eyes and the parallax allows the visual cortex to generate an depth perception, impression of depth. Optical design evolution Galilean Almost from the invention of the telescope in the 17th century the advantages of mounting two of them side by side for binocular vision seems to have been explored. Most early binoculars used Galilean telescope, Galilean optics; that is, they used a convex lens, convex objective (optics), objective and a concave lens, concave eyepi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kagoshima Prefecture
is a Prefectures of Japan, prefecture of Japan located on the island of Kyushu and the Ryukyu Islands. Kagoshima Prefecture has a population of 1,527,019 (1 February 2025) and has a geographic area of 9,187 Square kilometre, km2 (3,547 Square mile, sq mi). Kagoshima Prefecture borders Kumamoto Prefecture to the north and Miyazaki Prefecture to the northeast. Kagoshima is the capital and largest city of Kagoshima Prefecture, with other major cities including Kirishima, Kagoshima, Kirishima, Kanoya, Kagoshima, Kanoya, and Satsumasendai, Kagoshima, Satsumasendai. Kagoshima Prefecture is located at the southernmost point of Kyūshū and includes the Satsunan Islands group of the Ryukyu Islands. Kagoshima Prefecture's mainland territory extends from the Ariake Sea to Shibushi Bay on the Pacific Ocean coast, and is characterized by two large peninsulas created by Kagoshima Bay. Kagoshima Prefecture formed the core of the Satsuma Domain, ruled from Kagoshima Castle, one of the most imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
