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46 Hestia
Hestia ( minor planet designation: 46 Hestia) is a large, dark main-belt asteroid. It is also the primary body of the Hestia clump, a group of asteroids with similar orbits. Hestia was discovered by N. R. Pogson on August 16, 1857, at the Radcliffe Observatory, Oxford. Pogson awarded the honour of naming it to William Henry Smyth, the previous owner of the telescope used for the discovery. Smyth chose to name it after Hestia, Greek goddess of the hearth. This created a problem in Greek, where 4 Vesta also goes by the name ''Hestia''. The computed Lyapunov time for this asteroid is 30,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets. Hestia has been studied by radar. 13-cm radar observations of this asteroid from the Arecibo Observatory between 1980 and 1985 were used to produce a diameter estimate of 131 km. In 1988 a search for satellites or dust orbiting this asteroid was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norman Robert Pogson
Norman Robert Pogson, CIE (23 March 1829 – 23 June 1891) was an English astronomer who worked in India at the Madras observatory. He discovered several minor planets and made observations on comets. He introduced a mathematical scale of stellar magnitudes with the ratio of two successive magnitudes being the fifth root of one hundred (~2.512) and referred to as Pogson's ratio. Youth and education Norman was born in Nottingham, the son of George Owen Pogson, a hosiery manufacturer, lace dealer and commission agent, "with enough income to support an extended family", and his wife, Mary Ann. It was intended that he should follow his father into business, and he was accordingly sent for "commercial education", but he was fascinated by science, and his mother supported and encouraged this interest. His early education was largely informal. He left school at 16, intending to teach mathematics. At the age of eighteen, he calculated with the help of John Russell Hind of the Royal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyapunov Time
In mathematics, the Lyapunov time is the characteristic timescale on which a dynamical system is chaotic. It is named after the Russian mathematician Aleksandr Lyapunov. It is defined as the inverse of a system's largest Lyapunov exponent. Use The Lyapunov time mirrors the limits of the predictability of the system. By convention, it is defined as the time for the distance between nearby trajectories of the system to increase by a factor of '' e''. However, measures in terms of 2-foldings and 10-foldings are sometimes found, since they correspond to the loss of one bit of information or one digit of precision respectively. While it is used in many applications of dynamical systems theory, it has been particularly used in celestial mechanics Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Background Asteroids
Background may refer to: Performing arts and stagecraft * Background actor * Background artist * Background light * Background music * Background story * Background vocals * ''Background'' (play), a 1950 play by Warren Chetham-Strode Recorded works * ''Background'' (1953 film), a British drama * ''Background'' (1973 film), a documentary * ''Background'' (TV series), a Canadian journalistic television series * ''Background'' (Lifetime album), 1992 * ''Background'' (Bassi Maestro album), 2002 Science and engineering * Background extinction rate * Background independence, a condition in theoretical physics * Background noise * Background radiation, the natural radiation that is always present in a location ** Background (astronomy), small amounts of light coming from otherwise dark parts of the sky ** Cosmic background (other) ** Gravitational wave background ** X-ray background * Background process, software that is running but not being displayed * St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
19 Fortuna
Fortuna ( minor planet designation: 19 Fortuna) is one of the largest main-belt asteroids. It has a composition similar to 1 Ceres: a darkly colored surface that is heavily space-weathered with the composition of primitive organic compounds, including tholins. Fortuna is 225 km in diameter and has one of the darkest known geometric albedos for an asteroid over 150 km in diameter. Its albedo has been measured at 0.028 and 0.037. The spectra of the asteroid displays evidence of aqueous alteration. The Hubble Space Telescope observed Fortuna in 1993. It was resolved with an apparent diameter of 0.20 arcseconds (4.5 pixels in the Planetary Camera) and its shape was found to be nearly spherical. Satellites were searched for but none were detected. Stellar occultations by Fortuna have been observed several times. Fortuna has been studied by radar. It was discovered by J. R. Hind on August 22, 1852, and named after Fortuna, the Roman goddess of luck. Fortuna has b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perturbation (astronomy)
In astronomy, perturbation is the complex motion of a astronomical object, massive body subjected to forces other than the gravity, gravitational attraction of a single other massive physical body, body. The other forces can include a third (fourth, fifth, etc.) body, drag (physics), resistance, as from an atmosphere, and the off-center attraction of an oblate spheroid, oblate or otherwise misshapen body. Introduction The study of perturbations began with the first attempts to predict planetary motions in the sky. In ancient times the causes were unknown. Isaac Newton, at the time he formulated his laws of Newton's laws of motion, motion and of Newton's law of universal gravitation, gravitation, applied them to the first analysis of perturbations, recognizing the complex difficulties of their calculation. Many of the great mathematicians since then have given attention to the various problems involved; throughout the 18th and 19th centuries there was demand for accurate tables o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceres (dwarf Planet)
Ceres (; minor-planet designation: 1 Ceres) is a dwarf planet in the asteroid belt between the orbits of Mars and Jupiter. It was the first asteroid discovered, on 1 January 1801, by Giuseppe Piazzi at Palermo Astronomical Observatory in Sicily and announced as a new planet. Ceres was later classified as an asteroid and then a dwarf planetthe only one always inside Neptune's orbit. Ceres's small size means that even at its brightest, it is too dim to be seen by the naked eye, except under extremely dark skies. Its apparent magnitude ranges from 6.7 to 9.3, peaking at opposition (when it is closest to Earth) once every 15- to 16-month synodic period. As a result, its surface features are barely visible even with the most powerful telescopes, and little was known about it until the robotic NASA spacecraft ''Dawn'' approached Ceres for its orbital mission in 2015. ''Dawn'' found Ceres's surface to be a mixture of water ice, and hydrated minerals such as carbonates and cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnitude (astronomy)
In astronomy, magnitude is a unitless measure of the brightness of an object in a defined passband, often in the visible or infrared spectrum, but sometimes across all wavelengths. An imprecise but systematic determination of the magnitude of objects was introduced in ancient times by Hipparchus. The scale is logarithmic and defined such that a magnitude 1 star is exactly 100 times brighter than a magnitude 6 star. Thus each step of one magnitude is \sqrt \approx 2.512 times brighter than the magnitude 1 higher. The brighter an object appears, the lower the value of its magnitude, with the brightest objects reaching negative values. Astronomers use two different definitions of magnitude: apparent magnitude and absolute magnitude. The ''apparent'' magnitude () is the brightness of an object as it appears in the night sky from Earth. Apparent magnitude depends on an object's intrinsic luminosity, its distance, and the extinction reducing its brightness. The ''absolute'' magni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Curve
In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequency interval or Frequency band, band. Light curves can be periodic, as in the case of eclipsing binary, eclipsing binaries, Cepheid variables, other periodic variables, and Methods of detecting extrasolar planets#Transit photometry, transiting extrasolar planets, or aperiodic, like the light curve of a nova, a cataclysmic variable star, a supernova or a Gravitational microlensing, microlensing event or binary as observed during occultation events. The study of the light curve, together with other observations, can yield considerable information about the physical process that produces it or constrain the physical theories about it. Variable stars Graphs of the apparent magnitude of a variable star over time are commonly used to visua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Las Cruces, New Mexico
Las Cruces (; "the crosses") is the second-largest city in the U.S. state of New Mexico and the seat of Doña Ana County. As of the 2020 census the population was 111,385. Las Cruces is the largest city in both Doña Ana County and southern New Mexico. The Las Cruces metropolitan area had an estimated population of 213,849 in 2017. It is the principal city of a metropolitan statistical area which encompasses all of Doña Ana County and is part of the larger El Paso–Las Cruces combined statistical area. Las Cruces is the economic and geographic center of the Mesilla Valley, the agricultural region on the floodplain of the Rio Grande which extends from Hatch to the west side of El Paso, Texas. Las Cruces is the home of New Mexico State University (NMSU), New Mexico's only land-grant university. The city's major employer is the federal government on nearby White Sands Test Facility and White Sands Missile Range. The Organ Mountains, to the east, are dominant in the city's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photometry (astronomy)
Photometry, from Greek '' photo-'' ("light") and '' -metry'' ("measure"), is a technique used in astronomy that is concerned with measuring the flux or intensity of light radiated by astronomical objects. This light is measured through a telescope using a photometer, often made using electronic devices such as a CCD photometer or a photoelectric photometer that converts light into an electric current by the photoelectric effect. When calibrated against standard stars (or other light sources) of known intensity and colour, photometers can measure the brightness or apparent magnitude of celestial objects. The methods used to perform photometry depend on the wavelength region under study. At its most basic, photometry is conducted by gathering light and passing it through specialized photometric optical bandpass filters, and then capturing and recording the light energy with a photosensitive instrument. Standard sets of passbands (called a photometric system) are defined to all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauna Kea Observatories
The Mauna Kea Observatories (MKO) are a group of independent astronomical research facilities and large telescope observatories that are located at the summit of Mauna Kea on the Big Island of Hawaiʻi, United States. The facilities are located in a 525-acre (212 ha) special land use zone known as the "Astronomy Precinct", which is located within the 11,228-acre (4,544 ha) Mauna Kea Science Reserve. The Astronomy Precinct was established in 1967 and is located on land protected by the Historical Preservation Act for its significance to Hawaiian culture. The presence and continued construction of telescopes is highly controversial due to Mauna Kea's centrality in native Hawaiian religion and culture, as well as for a variety of environmental reasons. The location is near ideal because of its dark skies from lack of light pollution, good astronomical seeing, low humidity, high elevation of , position above most of the water vapor in the atmosphere, clean air, good wea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UH88
The University of Hawai'i 88-inch (2.24-meter) telescope—called UH88, UH2.2, or simply 88 by members of the local astronomical community—is situated at the Mauna Kea Observatories and operated by the University's Institute for Astronomy. It was constructed in 1968, and entered service in 1970, at which point it was known as "The Mauna Kea Observatory". It became one of the first professional telescopes to be controlled by a computer. The telescope was built with funding from NASA, to support Solar System missions, and is controlled by the University of Hawai'i. The success of the telescope helped demonstrate the value of Mauna Kea for astronomical observations. On December 4, 1984 it became the first telescope to make optical closure phase measurements on an astronomical source using an aperture mask. UH88 is a Cassegrain reflector tube telescope with an f/10 focal ratio, supported by a large open fork equatorial mount. It was the last telescope on Mauna Kea to use a tub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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