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1246 Chaka
1246 Chaka, provisional designation , is a background asteroid from the central regions of the asteroid belt, approximately in diameter. It was discovered on 23 July 1932, by South African astronomer Cyril Jackson at the Union Observatory in Johannesburg. The uncommon A/Sl-type asteroid has a longer than average rotation period of 25.5 hours. It was named for the Zulu King Shaka. Orbit and classification ''Chaka'' 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 1.8–3.4 AU once every 4 years and 3 months (1,549 days; semi-major axis of 2.62 AU). Its orbit has an eccentricity of 0.31 and an inclination of 16 ° with respect to the ecliptic. The body's observation arc begins with its first observation at Johannesburg on 4 July 1932, three weeks prior to its official discovery observation. Naming This minor planet was named after Shaka (c.1787–1828), also Chaka or Tchaka, foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyril Jackson (astronomer)
Cyril V. Jackson (5 December 1903 – February 1988) was a South African astronomer, known for discovering 72 asteroids and a number of comets. He was born in Ossett, Yorkshire in England; his father emigrated to South Africa in 1911. He earned his B.Sc. at the University of the Witwatersrand. He worked at Union Observatory in Johannesburg from 1928 to 1947 (IAU code 078, previously known as Transvaal Observatory and later known as Republic Observatory). He served with South African forces in the Second World War, and was mentioned in despatches. After the war he was director of the ''Yale-Columbia Southern Observatory'' (YCSO) station in Johannesburg (IAU code 077), which had been established by Yale University in the 1920s. Columbia University subsequently collaborated in that venture and the operation became known as the Yale-Columbia Southern Observatory (YCSO, Inc. was formally created in 1962). Due to light pollution that observatory had to be shut down in 1951 and h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid Family
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An asteroid family is a more specific term than asteroid group whose members, while sharing some broad orbital characteristics, may be otherwise unrelated to each other. General properties Large prominent families contain several hundred recognized asteroids (and many more smaller objects which may be either not-yet-analyzed, or not-yet-discovered). Small, compact families may have only about ten identified members. About 33% to 35% of asteroids in the main belt are family members. There are about 20 to 30 reliably recognized families, with several tens of less certain groupings. Most asteroid families are found in the main asteroid belt, although several family-like groups such as the Pallas family, Hungaria family, and the Phocaea family ... [...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] |
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] |
Herget's Discovery Circumstances
Paul Herget (January 30, 1908 – August 27, 1981) was an American astronomer and director of the Cincinnati Observatory, who established the Minor Planet Center after World War II. Career Herget taught astronomy at the University of Cincinnati. He was a pioneer in the use of machine methods, and eventually digital computers, in the solving of scientific and specifically astronomical problems (for example, in the calculation of ephemeris tables for minor planets). During World War II he applied these same talents to the war effort, helping to locate U-boats by means of the application of spherical trigonometry. Herget established the Minor Planet Center at the university after the war in 1947. He was also named director of the Cincinnati Observatory. The Minor Planet Center was eventually relocated in 1978 to the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, where it still operates. Awards and honors * In 1965 he was awarded the James Craig Watson Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Herget
Paul Herget (January 30, 1908 – August 27, 1981) was an American astronomer and director of the Cincinnati Observatory, who established the Minor Planet Center after World War II. Career Herget taught astronomy at the University of Cincinnati. He was a pioneer in the use of machine methods, and eventually digital computers, in the solving of scientific and specifically astronomical problems (for example, in the calculation of ephemeris tables for minor planets). During World War II he applied these same talents to the war effort, helping to locate U-boats by means of the application of spherical trigonometry. Herget established the Minor Planet Center at the university after the war in 1947. He was also named director of the Cincinnati Observatory. The Minor Planet Center was eventually relocated in 1978 to the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, where it still operates. Awards and honors * In 1965 he was awarded the James Craig Watson Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Names Of The Minor Planets
Paul Herget (January 30, 1908 – August 27, 1981) was an American astronomer and director of the Cincinnati Observatory, who established the Minor Planet Center after World War II. Career Herget taught astronomy at the University of Cincinnati. He was a pioneer in the use of machine methods, and eventually digital computers, in the solving of scientific and specifically astronomical problems (for example, in the calculation of ephemeris tables for minor planets). During World War II he applied these same talents to the war effort, helping to locate U-boats by means of the application of spherical trigonometry. Herget established the Minor Planet Center at the university after the war in 1947. He was also named director of the Cincinnati Observatory. The Minor Planet Center was eventually relocated in 1978 to the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, where it still operates. Awards and honors * In 1965 he was awarded the James Craig Watson Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zulu Kingdom
The Zulu Kingdom (, ), sometimes referred to as the Zulu Empire or the Kingdom of Zululand, was a monarchy in Southern Africa. During the 1810s, Shaka established a modern standing army that consolidated rival clans and built a large following which ruled a wide expanse of Southern Africa that extended along the coast of the Indian Ocean from the Tugela River in the south to the Pongola River in the north. A bitter civil war in the mid-19th century erupted which culminated in the 1859 Battle of Ndondakusuka between the brothers Cetshwayo and Mbuyazi. In 1879, a British force invaded Zululand, beginning the Anglo-Zulu War. After an initial Zulu victory at the Battle of Isandlwana in January, the British regrouped and defeated the Zulus in July during the Battle of Ulundi, ending the war. The area was absorbed into the Colony of Natal and later became part of the Union of South Africa. History Rise under Shaka Shaka was the illegitimate son of Senzangakhona, Chief of the ... [...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 ( |
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] |
Ecliptic
The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the background of stars. The ecliptic is an important reference plane and is the basis of the ecliptic coordinate system. Sun's apparent motion The ecliptic is the apparent path of the Sun throughout the course of a year. Because Earth takes one year to orbit the Sun, the apparent position of the Sun takes one year to make a complete circuit of the ecliptic. With slightly more than 365 days in one year, the Sun moves a little less than 1° eastward every day. This small difference in the Sun's position against the stars causes any particular spot on Earth's surface to catch up with (and stand directly north or south of) the Sun about four minutes later each day than it would if Earth did not orbit; a day on Earth is therefore 24 hours ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
