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99 Dike
99 Dike () is a quite large and dark main-belt asteroid. Dike was discovered by Alphonse Borrelly on May 28, 1868. It was his first asteroid discovery. This object is named after Dike, the Greek goddess of moral justice. Among the first hundred numbered minor planets, 99 Dike was considered anomalously faint for over a century. However, this was later found to be untrue. This asteroid is orbiting the Sun with a period of 4.35 years and an eccentricity of 0.19. Its orbital plane is inclined by 13.8° to the plane of the ecliptic. The body spans a diameter of 69 km and it is classified as a C-type asteroid, which indicates it has a dark, carbonaceous surface. Based upon a light curve that was generated from photometric observations of this asteroid at Pulkovo Observatory, it has a rotation period of 18.127 ± 0.002 hours and varies in brightness by 0.22 ± 0.02 in magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its mag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alphonse Borrelly
Alphonse Louis Nicolas Borrelly (December 8, 1842 – February 28, 1926) was a French astronomer born in Roquemaure, Gard. He joined the Marseille Observatory in 1864. In the course of his career, he discovered a number of asteroids and comets, including the periodic comet 19P/Borrelly. He also discovered five NGC objects, all galaxies. The French Academy of Sciences awarded him the Prix Valz for 1903 and the Prix Lalande for 1909. The asteroid 1539 Borrelly was named in his honor. In 1913, he received the Prix Jules Janssen, the highest award of the Société astronomique de France, the French astronomical society. Discoveries Comets discovered or co-discovered The following is an incomplete list of comets discovered or co-discovered by Borrelly: * C/1873 Q1 (Borrelly) * C/1877 C1 (Borrelly) * C/1877 G2 (Swift-Borrelly-Block) * C/1889 X1 (Borrelly) * C/1900 O1 (Borrelly–Brooks) * 19P/Borrelly Comet Borrelly or Borrelly's Comet (official designation: 19P/Borrell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Mythology
Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories concern the ancient Greek religion's view of the Cosmogony, origin and Cosmology#Metaphysical cosmology, nature of the world; the lives and activities of List of Greek deities, deities, Greek hero cult, heroes, and List of Greek mythological creatures, mythological creatures; and the origins and significance of the ancient Greeks' cult (religious practice), cult and ritual practices. Modern scholars study the myths to shed light on the religious and political institutions of ancient Greece, and to better understand the nature of mythmaking itself. The Greek myths were initially propagated in an oral tradition, oral-poetic tradition most likely by Minoan civilization, Minoan and Mycenaean Greece, Mycenaean singers starting in the 18th century&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-type Asteroids (Tholen)
C-type (carbonaceous ) asteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks and minerals. They have an average density of about . They lie most often at the outer edge of the asteroid belt, from the Sun, where 80% of the asteroids are of this type, whereas only 40% of asteroids at from the Sun are C-type. The proportion of C-types may actually be greater than this, since C-types are much darker (and hence less detectable) than most other asteroid types, except for D-types and others that lie mostly at the extreme outer edge of the asteroid belt. Characteristics Asteroids of this class have spectra very similar to those of carbonaceous chondrite meteorites (types CI and CM). The latter are very close in chemical composition to the Sun and the primitive solar nebula minus hydrogen, helium and other volatil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juno Clump
The Juno clump is a probable main-belt asteroid family that share similar orbital elements to 3 Juno. 3 Juno is a large asteroid with a mean diameter of about 235 km, but the remaining bodies are all small. , the brightest of those clearly in the visible clump would have a diameter of about 6 km, given the same albedo as 3 Juno. This indicates that it is probably a so-called cratering family composed of ejecta from impacts on 3 Juno. The HCM analysis by (Zappalà 1995) determined several likely core members, whose proper elements lie in the approximate ranges At the present epoch, the range of osculating orbital elements Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are considered in two-body systems using a Kepler orbit. There are many different ways to mathematically describe the same o ... of these core members is References * Zappalà, Vincenzo; Bendjoya, Philippe; Cellino, Alberto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnitude (astronomy)
In astronomy, magnitude is a measure of the brightness of an astronomical object, object, usually in a defined passband. An imprecise but systematic determination of the magnitude of objects was introduced in ancient times by Hipparchus. Magnitude values do not have a unit. The scale is Logarithmic scale, logarithmic and defined such that a magnitude 1 star is exactly 100 times brighter than a magnitude 6 star. Thus each step of one magnitude is \sqrt[5] \approx 2.512 times brighter than the magnitude 1 higher. The brighter an object appears, the lower the value of its magnitude, with the brightest objects reaching negative values. Astronomers use two different definitions of magnitude: apparent magnitude and absolute magnitude. The ''apparent'' magnitude () is the brightness of an object and depends on an object's intrinsic luminosity, its Cosmic distance ladder, distance, and the Extinction (astronomy), extinction reducing its brightness. The ''absolute'' magnitude () describes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulkovo Observatory
The Pulkovo Astronomical Observatory (), officially named the Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, is the principal astronomical observatory of the Russian Academy of Sciences. It is located 19 km south of Saint Petersburg on Pulkovo Heights above sea level. It is part of the UNESCO World Heritage Site Historic Centre of Saint Petersburg and Related Groups of Monuments. It was formerly known as the Imperial Observatory at Pulkowo. Early years The observatory was opened in 1839. Originally, it was a brainchild of the German/Russian astronomer Friedrich Georg Wilhelm von Struve, who would become its first director (in 1861, his son Otto Wilhelm von Struve succeeded him). The architect was Alexander Bryullov. The observatory was equipped with state-of-the-art devices, one of them being the a aperture refractor, one of the largest refractors in the world at that time (see Great Refractor). In 1885, the observatory was equipped wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photometry (astronomy)
In 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Curve
In astronomy, a light curve is a graph (discrete mathematics), graph of the Radiance, light intensity of a celestial object or region as a function of time, typically with the magnitude (astronomy), 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 frequency band, band. Light curves can be periodic, as in the case of eclipsing binary, eclipsing binaries, Cepheid variables, other periodic variables, and Methods of detecting extrasolar planets#Transit photometry, transiting extrasolar planets; or aperiodic, like the light curve of a nova, cataclysmic variable star, supernova, gravitational microlensing, microlensing event, or binary as observed during occultation events. The study of a light curve and other observations can yield considerable information about the physical process that produces such a light curve, or constrain the physical theories about it. Variable stars Graphs of the ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonaceous
Carbonaceous refers to something relating to, containing, or composed of carbon. It is a descriptor used for the attribute of any substance rich in carbon. Particularly, ''carbonaceous hydrocarbons'' are very unsaturated, high- molecular-weight hydrocarbons, having an elevated carbon:hydrogen ratio. The carbonaceous chondrites are meteorites that are rich in carbon. The word "carbonaceous" was first used in 1791. In geology, metamorphism of a carbonaceous geological material is expressed as a graphitisation process, referring to the graphite generated. Graphitisation may be accelerated or retarded in dependence on various metamorphic or lithological factors involved. See also * Carbonaceous chondrite * Carbonaceous film * Carbonaceous soil * C-type (carbonaceous) asteroid * Spheroidal carbonaceous particles Spheroidal carbonaceous particles (SCPs) is a form of black carbon produced from burning fossil fuels in energy production and heavy industry that is thought to provide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plane Of The Ecliptic
The ecliptic or ecliptic plane is the orbital plane of Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. 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 – specifically the Zodiac constellations. The planets of the Solar System can also be seen along the ecliptic, because their orbital planes are very close to Earth's. The Moon's orbital plane is also similar to Earth's; the ecliptic is so named because the ancients noted that eclipses only occur when the Moon is crossing it. The ecliptic is an important reference plane and is the basis of the ecliptic coordinate system. Ancient scientists were able to calculate Earth's axial tilt by comparing the ecliptic plane to that of the equator. Sun's apparent motion The ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planet's equator. For pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
