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19139 Apian
19139 Apian, provisional designation ', is a bright background asteroid from the central regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 6 April 1989, by German astronomer Freimut Börngen at the Karl Schwarzschild Observatory in Tautenburg, Eastern Germany. The asteroid was named for medieval German humanist Petrus Apianus. Orbit and classification ''Apian'' is a non-family asteroid from the main belt's background population. It orbits the Sun in the central asteroid belt at a distance of 2.4–2.8 AU once every 4 years and 2 months (1,516 days; semi-major axis of 2.58 AU). Its orbit has an eccentricity of 0.08 and an inclination of 8 ° with respect to the ecliptic. The body's observation arc begins with a precovery published in the Digitized Sky Survey and taken at Palomar Observatory in February 1989, approximately 2 months prior to its official discovery observation at Tautenburg. Physical characteristics The aster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freimut Börngen
Freimut Börngen (; 17 October 1930 – 19 June 2021) was a German astronomer and a prolific discoverer of minor planets. A few sources give his first name wrongly as "Freimuth". The Minor Planet Center credits him as F. Borngen. He studied galaxies with the Schmidt telescope at the Karl Schwarzschild Observatory in Tautenburg, Germany. In 1995 he retired, but continued to work as a freelancer for the observatory. As a by-product of his work, he discovered numerous asteroids (519, ). The research on asteroids had to be done in his spare time, as the search for small objects was not considered prestigious enough by the GDR research managers. During the GDR regime, Börngen restricted himself to politically neutral names for his asteroids, such as topics related to Thuringia or famous scientists and composers. Examples include 2424 Tautenburg, 3181 Ahnert, 3245 Jensch, or 3941 Haydn. After the German reunification, he chose systematically historical, cultural, scientific a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observation Arc
In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly used in the discovery and tracking of asteroids and comets. Arc length has the greatest influence on the accuracy of an orbit. The number and spacing of intermediate observations has a lesser effect. Short arcs A very short arc leaves a high uncertainty parameter. The object might be in one of many different orbits, at many distances from Earth. In some cases, the initial arc was too short to determine if the object was in orbit around the Earth, or orbiting out in the asteroid belt. With a 1-day observation arc, was thought to be a trans-Neptunian dwarf planet, but is now known to be a 1 km main-belt asteroid. With an observation arc of 3 days, was thought to be a Mars-crossing asteroid that could be a threat to Earth, but was later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apianus (crater)
Apianus is a lunar impact crater that is located on the rugged south-central highlands of the Moon. It is named after 16th century German mathematician and astronomer Petrus Apianus. It is located to the northeast of the crater Aliacensis, and to the northwest of Poisson. The worn crater Krusenstern is attached to the west-northwestern rim. Description The outer wall of the crater has been worn and eroded by subsequent impacts, and a pair of small craterlets overlay the rim to the southeast and northeast. The central crater is 63 kilometers in diameter and 2,080 meters deep.''Autostar Suite Astronomer Edition''. CD-ROM. Meade, April 2006. The craterlet on the southeast rim, Apianus B, is a member of a cluster of co-joined craterlets that includes Apianus T and Apianus U. The interior floor of the central crater is relatively smooth and lacks a central peak, although the surface appears somewhat convex. Only a few tiny craterlets mark the surface. The crater is from the Necta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomicum Caesareum
''Astronomicum Caesareum'' (''Astronomy of the Caesars''; also translated as ''The Emperor's Astronomy'') is a book by Petrus Apianus first published in 1540. ''Astronomicum'' was initially published in 1540. Charles V, Holy Roman Emperor, and Ferdinand II of Aragon commissioned the work. It was printed at Apianus's press in Ingolstadt, Bavaria, and took eight years to produce. It expanded and changed when reprinted; the final version has 55 leaves. Apianus evidently changed his plans while producing a single edition. A volvelle in one version of ''Astronomicum'' has "an entirely irrelevant base of an astrolabe" underneath, suggesting that he considered creating one and then abandoned the idea. Twenty-one of its 36 woodcuts are volvelles. ''Astronomicum'' volvelles rely on a geocentric model of the universe. However, despite the false science on which they depended, knowledgeable readers could still use them to predict planetary movements. Nicolaus Copernicus published ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sky Atlas
Celestial cartography, uranography, astrography or star cartography is the aspect of astronomy and branch of cartography concerned with mapping stars, galaxies, and other astronomical objects on the celestial sphere. Measuring the position and light of charted objects requires a variety of instruments and techniques. These techniques have developed from angle measurements with quadrants and the unaided eye, through sextants combined with lenses for light magnification, up to current methods which include computer-automated space telescopes. Uranographers have historically produced planetary position tables, star tables, and star maps for use by both amateur and professional astronomers. More recently, computerized star maps have been compiled, and automated positioning of telescopes uses databases of stars and of other astronomical objects. Etymology The word "uranography" derived from the Greek "ουρανογραφια" (Koine Greek ''ουρανος'' "sky, heave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minor Planet
According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor planet'', but that year's meeting reclassified minor planets and comets into dwarf planets and small Solar System bodies (SSSBs).Press release, IAU 2006 General Assembly: Result of the IAU Resolution votes International Astronomical Union, August 24, 2006. Accessed May 5, 2008. Minor planets include asteroids ( |
Astronomical Albedo
Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that reflects all incident radiation. Surface albedo is defined as the ratio of radiosity ''J''e to the irradiance ''E''e (flux per unit area) received by a surface. The proportion reflected is not only determined by properties of the surface itself, but also by the spectral and angular distribution of solar radiation reaching the Earth's surface. These factors vary with atmospheric composition, geographic location, and time (see position of the Sun). While bi-hemispherical reflectance is calculated for a single angle of incidence (i.e., for a given position of the Sun), albedo is the directional integration of reflectance over all solar angles in a given period. The temporal resolution may range from seconds (as obtained from flux measurements) to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, before being re-activated in 2013 and renamed the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE). WISE discovered thousands of minor planets and numerous star clusters. Its observations also supported the discovery of the first Y-type brown dwarf and Earth trojan asteroid. WISE performed an all-sky astronomical survey with images in 3.4, 4.6, 12 and 22 μm wavelength range bands, over ten months using a diameter infrared telescope in Earth orbit. After its solid hydrogen coolant depleted, a four-month mission extension called NEOWISE was conducted to search for near-Earth objects (NEO) such as comets and asteroids using its remaining capability. The WISE All-Sky (WISEA) data, including processed images, source cat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NEOWISE
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, before being re-activated in 2013 and renamed the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE). WISE discovered thousands of minor planets and numerous star clusters. Its observations also supported the discovery of the first Y-type brown dwarf and Earth trojan asteroid. WISE performed an all-sky astronomical survey with images in 3.4, 4.6, 12 and 22 μm wavelength range bands, over ten months using a diameter infrared telescope in Earth orbit. After its solid hydrogen coolant depleted, a four-month mission extension called NEOWISE was conducted to search for near-Earth objects (NEO) such as comets and asteroids using its remaining capability. The WISE All-Sky (WISEA) data, including processed images, source cata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotation Period
The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the background stars, measured in sidereal time. The other type of commonly used rotation period is the object's synodic rotation period (or ''solar day''), measured in solar time, which may differ by a fraction of a rotation or more than one rotation to accommodate the portion of the object's orbital period during one day. Measuring rotation For solid objects, such as rocky planets and asteroids, the rotation period is a single value. For gaseous or fluid bodies, such as stars and gas giants, the period of rotation varies from the object's equator to its pole due to a phenomenon called differential rotation. Typically, the stated rotation period for a gas giant (such as Jupiter, Saturn, Uranus, Neptune) is its internal rotation period, as d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightcurve
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 band. Light curves can be periodic, as in the case of eclipsing binaries, Cepheid variables, other periodic variables, and transiting extrasolar planets, or aperiodic, like the light curve of a nova, a cataclysmic variable star, a supernova or a 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 visualise and analyse their behaviour. Although the categorisation of variable star types is increasingly done from their spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid Spectral Type
An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated, the surface and internal compositions are presumably similar, while large bodies such as Ceres and Vesta are known to have internal structure. Over the years, there has been a number of surveys that resulted in a set of different taxonomic systems such as the Tholen, SMASS and Bus–DeMeo classifications. Taxonomic systems In 1975, astronomers Clark R. Chapman, David Morrison, and Ben Zellner developed a simple taxonomic system for asteroids based on color, albedo, and spectral shape. The three categories were labelled " C" for dark carbonaceous objects, " S" for stony (silicaceous) objects, and "U" for those that did not fit into either C or S. This basic division of asteroid spectra has since been expanded and clarified.Thomas H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
