A-type Asteroids (Tholen)
A-type asteroids are relatively uncommon inner-belt asteroids that have a strong, broad 1 μm olivine feature and a very reddish spectrum shortwards of 0.7 μm. They are thought to come from the completely differentiated mantle of an asteroid, and appear to have a high density. One survey found that 7 similar A-, V- and X-type asteroids had an average density of .P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. ''Astronomy & Astrophysics'' 54, A56 List A-type asteroids are so rare that as of February 2019, only 17 had been discovered: See also *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 differentiate ... References External links Mineralogic and Temperature-Induced Spectral Investigation ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. Of the roughly one million known asteroids the greatest number are located between the orbits of Mars and Jupiter, approximately 2 to 4 AU from the Sun, in the main asteroid belt. Asteroids are generally classified to be of three types: C-type, M-type, and S-type. These were named after and are generally identified with carbonaceous, metallic, and silicaceous compositions, respectively. The size of asteroids varies greatly; the largest, Ceres, is almost across and qualifies as a dwarf planet. The total mass of all the asteroids combined is only 3% that of Earth's Moon. The majority of main belt asteroids follow slightly elliptical, stable orbits, revolving in the same direction as the Earth and taking from three to six years to comple ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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2423 Ibarruri
2423 Ibarruri, provisional designation , is an eccentric, tumbling and rare-type asteroid, classified as slow rotator and sizable Mars-crosser from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. The asteroid was discovered by Russian–Ukrainian astronomer Lyudmila Zhuravleva at the Crimean Astrophysical Observatory in Nauchnyj, on 14 July 1972. It was named after Spanish communist Rubén Ruiz Ibárruri. Orbit and classification ''Ibarruri'' orbits the Sun in the inner main-belt at a distance of 1.6–2.8 AU once every 3 years and 3 months (1,183 days). Its orbit has an eccentricity of 0.28 and an inclination of 4 ° with respect to the ecliptic. Physical characteristics The spectral type of the asteroid is that of a rare A-type in the SMASS taxonomy, with its surface consisting of almost pure olivine, which gives the body a very reddish color. As of November 2015, only 17 minor planets of this type are known. As a spectroscopic A ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Vishnu Vardhan Reddy
This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 numbered minor planets are credited to 1141 astronomers and 253 observatories, telescopes or surveys ''(see )''. On how a discovery is made, ''see observations of small Solar System bodies. For a description of the tables below, see ''. Discovering astronomers }, (bio-de) , align=left , M. Matsuyama , , - id="D. Matter" , align=left , Daniel Matter , 7 , 1957–pres. , , align=left , D. Matter; amateur, (bio-it) , align=left , D. Matter , , - id="A. Maury" , align=left , Alain Maury , 9 , 1958–pres. , , align=left , A. Maury; , align=left , A. Maury , , - id="D. Mayes" , align=left , Deronda Mayes , , 1957–pres. , , align=left , D. Mayes; inferred , align=left , D. Mayes , , - id="E. Mazzo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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5641 McCleese
5641 McCleese, provisional designation , is a rare-type Hungaria asteroid and slow rotator, classified as Mars-crosser from the innermost regions of the asteroid belt, approximately 4 kilometers in diameter. It was discovered on 27 February 1990, by American astronomer Eleanor Helin at Palomar Observatory in California, and later named for JPL-scientist Daniel McCleese. Classification and orbit ''McCleese'' is classified as a bright and rare A-type asteroid in the SMASS taxonomy. It is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. With a perihelion of 1.589 AU, ''McCleese'' also crosses the orbit of Mars. The asteroid orbits the Sun in the innermost main-belt at a distance of 1.6–2.0 AU once every 2 years and 5 months (896 days). Its orbit has an eccentricity of 0.13 and an inclination of 22 ° with respect to the ecliptic. In 1973, it was first identified as at Lick Observatory, extending ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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4982 Bartini
__NOTOC__ Year 498 ( CDXCVIII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Paulinus and Scytha (or, less frequently, year 1251 '' Ab urbe condita''). The denomination 498 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Byzantine Empire * Emperor Anastasius I abolishes the chrysargyron tax throughout the Eastern Roman Empire, before reforming the monetary system, using Greek numerals instead of Roman. Persia * Kavadh I returns from exile with support of 30,000 Hephthalites (White Huns), and again assumes the Sassanid throne. He punishes his opponents and probably his brother Djamasp, who usurped the throne from him. Japan * Prince Buretsu, age 9, succeeds his father Ninken and becomes the 25th emperor. By topic Religion * No ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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4713 Steel
4713 Steel, provisional designation , is a rare-type Hungaria asteroid from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 26 August 1989, by Scottish–Australian astronomer Robert McNaught at the Siding Spring Observatory in New South Wales, Australia. It was named after astronomer Duncan Steel. Classification and orbit The rare and reddish A-type asteroid is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun in the inner main-belt at a distance of 1.8–2.1 AU once every 2 years and 8 months (977 days). Its orbit has an eccentricity of 0.07 and an inclination of 23 ° with respect to the ecliptic. A first precovery was taken at the discovering observatory in 1976, extending the asteroid's observation arc by 13 years prior to its official discovery observation in 1989. Lightcurves In May 2005, the first rotational lightcurve was ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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4142 Dersu-Uzala
4142 Dersu-Uzala, provisional designation ', is a Hungaria asteroid, sizable Mars-crosser and potentially slow rotator from the innermost region of the asteroid belt, approximately in diameter. It was discovered by Czech astronomer Zdeňka Vávrová at Kleť Observatory on 28 May 1981. The rare A-type asteroid has a rotation period of 140 hours. It was named after the Siberian trapper and hunter Dersu Uzala. Orbit and characterization ''Dersu-Uzala'' is a member of the dynamical Hungaria group of asteroids, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun in the inner asteroid belt at a distance of 1.6–2.2 AU once every 2 years and 8 months (965 days; semi-major axis of 1.91 AU). Its orbit has an eccentricity of 0.15 and an inclination of 26 ° with respect to the ecliptic. As its orbit crosses that of Mars at 1.66 AU, it is also a Mars crossing asteroid. The body's observation arc begins with its first obser ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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3352 McAuliffe
3352 McAuliffe (), provisional designation , is a rare-type asteroid and suspected binary system, classified as near-Earth object of the Amor group, approximately 2 kilometers in diameter. It was discovered on 6 February 1981, by American astronomer Norman Thomas at Lowell's Anderson Mesa Station near Flagstaff, Arizona, United States. Originally, this asteroid was the target of the 1998 Deep Space 1 mission, but that mission was eventually rerouted to 9969 Braille. It was named in memory of Challenger crew member Christa McAuliffe. Orbit ''McAuliffe'' orbits the Sun at a distance of 1.2–2.6 AU once every 2 years and 7 months (941 days). Its orbit has an eccentricity of 0.37 and an inclination of 5 ° with respect to the ecliptic. It has an ''Earth minimum orbital intersection distance'' of , which translates into 79.5 lunar distances. Due to its eccentric orbit, ''McAuliffe'' is also a Mars-crosser. As no precoveries were taken, and no prior identifications were m ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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2732 Witt
2732 Witt, provisional designation , is a bright asteroid and namesake of the Witt family located in the central regions of the asteroid belt, approximately in diameter. It was discovered on 19 March 1926, by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory in Heidelberg, Germany. The unusual A-type asteroid was named after astronomer Carl Gustav Witt. Orbit and classification ''Witt'' the parent body and namesake of the Witt family (), a large family of stony asteroids with more than 1,600 known members. It orbits the Sun in the central main-belt at a distance of 2.7–2.8 AU once every 4 years and 7 months (1,675 days; semi-major axis of 2.76 AU). Its orbit has an eccentricity of 0.02 and an inclination of 6 ° with respect to the ecliptic. The body's observation arc begins at Heidelberg in April 1926, two week after its official discovery observation. Physical characteristics In the SMASS classification, ''Witt'' is an uncommon ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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2715 Mielikki
__NOTOC__ Year 715 ( DCCXV) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. The denomination 715 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Byzantine Empire * May – Emperor Anastasios II is deposed in an army mutiny, and succeeded by Theodosius III, a tax-collector from the ''theme'' of Opsikion (modern Turkey). After a six-month siege, Theodosius and his troops take Constantinople; Anastasios is forced to abdicate the throne, and retires to a monastery in Thessaloniki ( Macedonia). Europe * September 26 – Battle of Compiègne: Ragenfrid, mayor of the palace of Neustria and Burgundy (appointed by King Dagobert III), defeats Theudoald in the first battle of the Frankish civil war, following the death of Pepin II (of Herstal). * Dagobert III dies of an illness and is succeeded by ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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2501 Lohja
5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number. It has attained significance throughout history in part because typical humans have five digits on each hand. In mathematics 5 is the third smallest prime number, and the second super-prime. It is the first safe prime, the first good prime, the first balanced prime, and the first of three known Wilson primes. Five is the second Fermat prime and the third Mersenne prime exponent, as well as the third Catalan number, and the third Sophie Germain prime. Notably, 5 is equal to the sum of the ''only'' consecutive primes, 2 + 3, and is the only number that is part of more than one pair of twin primes, ( 3, 5) and (5, 7). It is also a sexy prime with the fifth prime number and first prime repunit, 11. Five is the third factorial prime, an alternating factorial, and an Eisenstein prime with no imaginary part and real part of the for ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |