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1998 Titius
1998 Titius, provisional designation , is a metallic–carbonaceous asteroid from the inner regions of the asteroid belt, approximately 14 kilometers in diameter. It was discovered on 24 February 1938, by German astronomer Alfred Bohrmann at Heidelberg Observatory in southern Germany. On the same night, the body was also observed at the Finnish Turku Observatory. It was later named after astronomer Johann Daniel Titius. Orbit and classification ''Titius'' orbits the Sun in the inner main-belt at a distance of 2.3–2.6 AU once every 3 years and 9 months (1,375 days). Its orbit has an eccentricity of 0.06 and an inclination of 8 ° with respect to the ecliptic. It stays in a 2:1 orbital resonance with the planet Mars. ''Titius'' observation arc starts on the night following its official discovery observation. Physical characteristics Diameter and albedo According to observations carried out by the Japanese Akari and NASA's Wide-field Infrared Survey Explorer (WISE) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Bohrmann
Alfred Bohrmann (February 28, 1904 – January 4, 2000) was a German astronomer and discoverer of minor planets. He did his Ph.D. dissertation in 1927 at the Heidelberg-Königstuhl State Observatory, at the University of Heidelberg. At the time, the observatory at Heidelberg was a center for asteroid discovery by Max Wolf and Karl Reinmuth Karl Wilhelm Reinmuth (4 April 1892 in Heidelberg – 6 May 1979 in Heidelberg) was a German astronomer and a prolific discoverer of 395 minor planets. Scientific career From 1912 to 1957, Reinmuth was working as an astronomer at the Lande ... and others, and during his time there Bohrmann discovered 9 asteroids. Bohrmann worked there from 1924 to 1969, publishing more than 700 minor planet observations. He left the observatory after a dispute with the higher authority. The asteroid 1635 Bohrmann is named after him. References External links *Obituary 1904 births 2000 deaths Discoverers of asteroids 20th-century Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Daniel Titius
Johann Daniel Titius (born Johann Daniel Tietz(e), 2 January 1729 – 16 December 1796) was a German astronomer and a professor at Wittenberg.sächsische Biografie Titius was born in Konitz (Chojnice), (a fief of the ) to Jakob Tietz, a merchant and council member from Konitz, and Maria Dorothea, née Hanow. His original name was Johann Tietz, but as was customary in the 18th century, when he became a university professor, he Latinized his surname to Titius. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-type Asteroids
The X-group of asteroids collects together several types with similar spectra, but probably quite different compositions. Tholen classification In the Tholen classification the X-group consists of the following types: * E-type – with high albedo (> 0.30), composed of enstatite, forsterite and feldspar. They are found in the inner main-belt. * M-type – the largest grouping, intermediate albedo, "metallic", composed of iron and nickel, thought to be the progenitors of nickel–iron meteorites. They are found around 3.0 AU and in the Hungaria region (innermost main-belt). * P-type – low albedos (< 0.10) with featureless red spectra; presumably composed of carbonaceous chondrites, and found in the outer main-belt and in the Jupiter trojan region. Since in this scheme the albedo is crucial in discriminating between the above types, some objects for which albedo information was not available were assigned an X-type. An example of this is 50 Virginia. SMASS classi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid Spectral Types
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absolute Magnitude
Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it were viewed from a distance of exactly , without extinction (or dimming) of its light due to absorption by interstellar matter and cosmic dust. By hypothetically placing all objects at a standard reference distance from the observer, their luminosities can be directly compared among each other on a magnitude scale. As with all astronomical magnitudes, the absolute magnitude can be specified for different wavelength ranges corresponding to specified filter bands or passbands; for stars a commonly quoted absolute magnitude is the absolute visual magnitude, which uses the visual (V) band of the spectrum (in the UBV photometric system). Absolute magnitudes are denoted by a capital M, with a subscript representing the filter band used for mea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Albedo
Albedo (; ) is the measure of the diffuse reflection of sunlight, 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 (radiometry), 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 ob ... [...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, sour ... [...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, so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akari (satellite)
Akari (ASTRO-F) was an infrared astronomy satellite developed by Japan Aerospace Exploration Agency, in cooperation with institutes of Europe and Korea. It was launched on 21 February 2006, at 21:28 UTC (06:28, 22 February JST) by M-V rocket into Earth sun-synchronous orbit. After its launch it was named ''Akari'' (明かり), which means ''light'' in Japanese. Earlier on, the project was known as IRIS (InfraRed Imaging Surveyor). Its primary mission was to survey the entire sky in near-, mid- and far-infrared, through its aperture telescope. Technical design Its designed lifespan, of far- and mid-infrared sensors, was 550 days, limited by its liquid helium coolant. Its telescope mirror was made of silicon carbide to save weight. The budget for the satellite was ¥13,4 billion (~). History By mid-August 2006, Akari finished around 50 percent of the all sky survey. By early November 2006, first (phase-1) all-sky survey finished. Second (phase-2) all-sky survey star ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin atmosphere (less than 1% that of Earth's), and has a crust primarily composed of elements similar to Earth's crust, as well as a core made of iron and nickel. Mars has surface features such as impact craters, valleys, dunes and polar ice caps. It has two small and irregularly shaped moons, Phobos and Deimos. Some of the most notable surface features on Mars include Olympus Mons, the largest volcano and highest known mountain in the Solar System and Valles Marineris, one of the largest canyons in the Solar System. The Borealis basin in the Northern Hemisphere covers approximately 40% of the planet and may be a large impact feature. Days and seasons on Mars are comparable to those of Earth, as the planets have a similar rotation period a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Resonance
In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relationship is found between a pair of objects (binary resonance). The physical principle behind orbital resonance is similar in concept to pushing a child on a swing, whereby the orbit and the swing both have a natural frequency, and the body doing the "pushing" will act in periodic repetition to have a cumulative effect on the motion. Orbital resonances greatly enhance the mutual gravitational influence of the bodies (i.e., their ability to alter or constrain each other's orbits). In most cases, this results in an ''unstable'' interaction, in which the bodies exchange momentum and shift orbits until the resonance no longer exists. Under some circumstances, a resonant system can be self-correcting and thus stable. Examples are the 1:2:4 resonance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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