|
5656 Oldfield
5656 Oldfield, provisional designation , is a background asteroid from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 8 October 1920, by astronomer Walter Baade at the Bergedorf Observatory in Hamburg, Germany. The asteroid was named for English musician Mike Oldfield. Orbit and classification ''Oldfield'' is a non-family asteroid of the main belt's Background asteroid, background population. It orbits the Sun in the Kirkwood gap, inner main-belt at a distance of 1.8–3.1 Astronomical unit, AU once every 3 years and 10 months (1,409 days; semi-major axis of 2.46 AU). Its orbit has an orbital eccentricity, eccentricity of 0.26 and an orbital inclination, inclination of 4Degree (angle), ° with respect to the ecliptic. The body's observation arc begins at Bergedorf two nights after its official discovery observation. Physical characteristics Diameter and albedo According to the survey carried out by the NEOWISE mission ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Baade
Wilhelm Heinrich Walter Baade (March 24, 1893 – June 25, 1960) was a German astronomer who worked in the United States from 1931 to 1959. Biography The son of a teacher, Baade finished school in 1912. He then studied maths, physics and astronomy at the universities of Münster and Göttingen. After receiving his PhD in 1919, Baade worked at Hamburg Observatory at Bergedorf from 1919 to 1931. There in 1920 he discovered 944 Hidalgo, the first of a class of minor planets now called Centaurs which cross the orbits of giant planets. He worked at Mount Wilson Observatory from 1931 to 1958. There, during World War II, he took advantage of wartime blackout conditions (which reduced light pollution), to resolve stars in the center of the Andromeda Galaxy for the first time. These observations led him to define distinct "populations" for stars (Population I and Population II). The same observations led him to discover that there are two types of Cepheid variable stars. Using this disc ... [...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] |
Jet Propulsion Laboratory
The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA and managed by the nearby California Institute of Technology (Caltech). The laboratory's primary function is the construction and operation of planetary robotic spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating the NASA Deep Space Network. Among the laboratory's major active projects are the Mars 2020 mission, which includes the ''Perseverance'' rover and the '' Ingenuity'' Mars helicopter; the Mars Science Laboratory mission, including the ''Curiosity'' rover; the InSight lander (''Interior Exploration using Seismic Investigations, Geodesy and Heat Transport''); the ''Mars Reconnaissance Orbiter''; the ''Juno'' spacecraft orbiting Jupiter; the ''SMAP'' satellite for earth surface s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minor Planet Circulars
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Function The Minor Planet Center is the official worldwide organization in charge of collecting observational data for minor planets (such as asteroids), calculating their orbits and publishing this information via the '' Minor Planet Circulars''. Under the auspices of the International Astronomical Union (IAU), it operates at the Smithsonian Astrophysical Observatory, which is part of the Center for Astrophysics along with the Harvard College Observatory. The MPC runs a number of free online services for observers to assist them in observing minor planets and comets. The complete catalogue of minor planet orbits (sometimes referred to as the "Minor Planet Catalogue") may also be freely downloaded. In addition to astrometric data, the MPC collect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Function The Minor Planet Center is the official worldwide organization in charge of collecting observational data for minor planets (such as asteroids), calculating their orbits and publishing this information via the '' Minor Planet Circulars''. Under the auspices of the International Astronomical Union (IAU), it operates at the Smithsonian Astrophysical Observatory, which is part of the Center for Astrophysics along with the Harvard College Observatory. The MPC runs a number of free online services for observers to assist them in observing minor planets and comets. The complete catalogue of minor planet orbits (sometimes referred to as the "Minor Planet Catalogue") may also be freely downloaded. In addition to astrometric data, the MPC collect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gareth V
Sir Gareth (; Old French: ''Guerehet'', ''Guerrehet'') is a Knight of the Round Table in Arthurian legend. He is the youngest son of King Lot and Queen Morgause, King Arthur's half-sister, thus making him Arthur's nephew, as well as brother to Gawain, Agravain and Gaheris, and either a brother or half-brother of Mordred. Gareth is particularly notable in ''Le Morte d'Arthur'' in which he is also known by his nickname Beaumains. Arthurian legend French literature The earliest role of Gareth, appearing as Guerrehet, is found in the First Continuation of Chrétien de Troyes's ''Perceval ou le Conte du Graal''. As the protagonist of the story's final episode, he slays the giant known as "Little Knight", thus avenging the death of fairy king Brangemuer, son of Guingamuer and the fay Brangepart. Several of his adventures are narrated in the Vulgate Cycle (''Lancelot-Grail''). In the Vulgate ''Merlin'', Gareth and his brothers defect from their father King Lot and take service wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubular Bells
Tubular bells (also known as chimes) are musical instruments in the percussion family. Their sound resembles that of church bells, carillon, or a bell tower; the original tubular bells were made to duplicate the sound of church bells within an ensemble.James Blades and James Holland. "Tubular bells". Grove Music Online. Oxford Music Online. Oxford University Press, accessed August 18, 2015Oxfordmusiconline.com/ref> Each bell is a metal tube, in diameter, tuned by altering its length. Its standard range is C4–F5, though many professional instruments reach G5. Tubular bells are often replaced by studio chimes, which are a smaller and usually less expensive instrument. Studio chimes are similar in appearance to tubular bells, but each bell has a smaller diameter than the corresponding bell on tubular bells. Tubular bells are sometimes struck on the top edge of the tube with a rawhide- or plastic-headed hammer. Often, a sustain pedal will be attached to allow extended ringing ... [...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 ( |
Poles Of Astronomical Bodies
The poles of astronomical bodies are determined based on their axis of rotation in relation to the celestial poles of the celestial sphere. Astronomical bodies include stars, planets, dwarf planets and small Solar System bodies such as comets and minor planets (e.g., asteroids), as well as natural satellites and minor-planet moons. Poles of rotation The International Astronomical Union (IAU) defines the north pole of a planet or any of its satellites in the Solar System as the planetary pole that is in the same celestial hemisphere, relative to the invariable plane of the Solar System, as Earth's north pole. This definition is independent of the object's direction of rotation about its axis. This implies that an object's direction of rotation, when viewed from above its north pole, may be either clockwise or counterclockwise. The direction of rotation exhibited by most objects in the solar system (including Sun and Earth) is counterclockwise. Venus rotates clockwise, and Uranus h ... [...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] |
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 allow a ... [...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] |
