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76 Freia
76 Freia is a very large main-belt asteroid. It orbits in the outer part of the asteroid belt and is classified as a Cybele asteroid. Its composition is very primitive and it is extremely dark in color. Freia was discovered by the astronomer Heinrich d'Arrest on 21 October 1862, in Copenhagen, Denmark. It was his first and only asteroid discovery. It is named after the goddess Freyja in Norse mythology. The sidereal orbital period of this asteroid is commensurable with that of Jupiter, which made it useful for ground-based mass estimates of the giant planet. A shape model for the asteroid was published by Stephens and Warner (2008), based upon lightcurve data. This yielded a sidereal rotation period of . They found two possible solutions for the spin axis, with the preferred solution in ecliptic coordinates being (λ, β) = (, ). References External links * * Cybele asteroids Freia Freia Freia may refer to: * Freyja In Norse mythology, Freyja (Old Norse "(the) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinrich D'Arrest
Heinrich Louis d'Arrest (13 August 1822 – 14 June 1875; ) was a Germans, German astronomer, born in Berlin. His name is sometimes given as Heinrich Ludwig d'Arrest. Biography While still a student at the Humboldt University of Berlin, University of Berlin, d'Arrest was party to Johann Gottfried Galle's search for Neptune. On 23 September 1846, he suggested that a recently drawn chart of the sky, in the region of Urbain Le Verrier's predicted location, could be compared with the current sky to seek the displacement characteristic of a planet, as opposed to a stationary star. Neptune was Discovery of Neptune, discovered that very night. D'Arrest's later work at the :de:Sternwarte Leipzig, Leipzig Observatory led him, in 1851, to the discovery of the comet named for him (formally designated Comet d'Arrest, 6P/d'Arrest). He also studied asteroids, discovering 76 Freia, nebulae, and galaxies, discovering NGC 1 in 1861 and NGC 26 and NGC 358 in 1865. In 1864 D'Arrest made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Period
The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars. It may also refer to the time it takes a satellite orbiting a planet or moon to complete one orbit. For celestial objects in general, the orbital period is determined by a 360° revolution of one body around its primary, ''e.g.'' Earth around the Sun. Periods in astronomy are expressed in units of time, usually hours, days, or years. Its reciprocal is the orbital frequency, a kind of revolution frequency, in units of hertz. Small body orbiting a central body According to Kepler's Third Law, the orbital period ''T'' of two point masses orbiting each other in a circular or elliptic orbit is: :T = 2\pi\sqrt where: * ''a'' is the orbit's semi-major axis * ''G'' is the gravitationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-type Asteroids (Tholen)
P-type (primitive-type) asteroids have low albedo and a featureless reddish Asteroid spectral types, spectrum. It has been suggested that they have a composition of organic-rich silicates, carbon and anhydrous silicates, possibly with water ice in their interior. P-type asteroids are found in the outer asteroid belt and beyond. There are about 33 known P-type asteroids, depending on the classification, including 46 Hestia, 65 Cybele, 76 Freia, 87 Sylvia, 153 Hilda, 476 Hedwig and, in some classifications, 107 Camilla. Taxonomy An early system of asteroid taxonomy was established in 1975 from the doctoral thesis work of David J. Tholen. This was based upon observations of a group of 110 asteroids. The U-type classification was used as a miscellaneous class for asteroids with unusual spectra that did not fit into the C-type asteroid, C and S-type asteroid classifications. In 1976, some of these U-type asteroids with unusual moderate albedo levels were labeled as M-type asteroid, M-t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Named Minor Planets
Named may refer to something that has been given a name. Named may also refer to: * named (computing), a widely used DNS server * Naming (parliamentary procedure) * The Named (band), an American industrial metal group In literature: * ''The Named'', a fantasy novel by Marianne Curley * The Named, a fictional race of prehistoric big cats, depicted in ''The Books of the Named'' series by Clare Bell See also * Name (other) * Names (other) Names are words or terms used for identification. Names may also refer to: * ''Names'' (EP), by Johnny Foreigner * ''Names'' (journal), an academic journal of onomastics * The Names (band), a Belgian post-punk band * ''The Names'' (novel), b ... * Naming (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discoveries By Heinrich Louis D'Arrest
Discoveries may refer to: Media Film and television * ''Discoveries'' (film), a 1939 British film * ''Discoveries'' (TV series), a Canadian youth science television series * "Discoveries", a Series D episode of the television series ''QI'' (2006) * "Discoveries" (''Hotel Portofino''), a 2022 TV episode Literature * ''Discoveries'' (Robertson Davies), a 2002 book by Robertson Davies * ''Abrams Discoveries'', a series of illustrated non-fiction books published by Harry N. Abrams * ''Discoveries'', a work by William Butler Yeats, written in 1907 * ''Discoveries'', a magazine published by Cedars-Sinai Medical Center Music * ''Discoveries'' (Cannonball Adderley album), 1955 * ''Discoveries'' (Josh Nelson album), 2011 * ''Discoveries'' (Northlane album), 2011 Other uses * Discoveries (horse), a racehorse See also * Age of Discoveries * Discovery (other) * Explorations (other) Exploration is the process of discovery. Exploration or explorations may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cybele Asteroids
The Cybele asteroids (also known as the "Cybeles") are a dynamical group of asteroids, named after the asteroid 65 Cybele. Considered by some as the last outpost of an extended asteroid belt, the group consists of just over 2000 members and a few collisional families. The Cybeles are in a 7:4 orbital resonance with Jupiter. Their orbit is defined by an osculating semi-major axis of 3.27 to 3.70 AU, with an eccentricity of less than 0.3, and an inclination less than 30°. The dynamical Cybele group is located adjacent to the outermost asteroid belt, beyond the Hecuba gap – the 2:1 resonant zone with Jupiter, where the Griqua asteroids are located – and inside the orbital region of the Hilda asteroids (3:2 resonance), which are themselves followed by the Jupiter trojans (1:1 resonance) further out. Description Three known asteroid families exist within the Cybele group: the Sylvia family ( 603), the Huberta family and the Ulla family (903). A potential fourth f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary And Space Science
''Planetary and Space Science'' (P&SS), published 15 times per year, is a peer-reviewed scientific journal established in 1959. It publishes original research articles along with short communications (letters). The main topic is Solar System processes which encompasses multiple areas of the natural sciences. Numerical simulations of solar system processes are also conducted at ground-based facilities or on-board space platforms. The editor-in-chief is Maria Cristina De Sanctis (National Institute of Astrophysics, Roma, Italy). It is published by Elsevier. Scope Research that involves planetary and space sciences involves many disciplines, which is reflected by the scope of the journal. Basic science Celestial mechanics is part of these studies, as this science includes understanding the dynamic evolution of the Solar System, relativistic effects, among other areas of analysis and consideration. Cosmochemistry is also part of the published research in this journal. Cosmoch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecliptic Coordinates
In astronomy, the ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions, orbits, and pole orientations of Solar System objects. Because most planets (except Mercury) and many small Solar System bodies have orbits with only slight inclinations to the ecliptic, using it as the fundamental plane is convenient. The system's origin can be the center of either the Sun or Earth, its primary direction is towards the March equinox, and it has a right-hand convention. It may be implemented in spherical or rectangular coordinates. Primary direction The celestial equator and the ecliptic are slowly moving due to perturbing forces on the Earth, therefore the orientation of the primary direction, their intersection at the March equinox, is not quite fixed. A slow motion of Earth's axis, precession, causes a slow, continuous turning of the coordinate system westward about the poles of the ecliptic, completing one circu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotation Period
In astronomy, the rotation period or spin period of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the '' sidereal rotation period'' (or ''sidereal day''), i.e., the time that the object takes to complete a full rotation around its axis relative to the background stars ( inertial space). The other type of commonly used "rotation period" is the object's '' synodic rotation period'' (or ''solar day''), which may differ, by a fraction of a rotation or more than one rotation, to accommodate the portion of the object's orbital period around a star or another body 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 giant planets, 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 giant pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightcurve
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] |
Giant Planet
A giant planet, sometimes referred to as a jovian planet (''Jove'' being another name for the Roman god Jupiter (mythology), Jupiter), is a diverse type of planet much larger than Earth. Giant planets are usually primarily composed of low-boiling point materials (volatile (astrogeology), volatiles), rather than rock (geology), rock or other solid matter, but massive solid planets can also exist. There are four such planets in the Solar System: Jupiter, Saturn, Uranus, and Neptune. Many exoplanet, extrasolar giant planets have been identified. Giant planets are sometimes known as gas giants, but many astronomers now apply the term only to Jupiter and Saturn, classifying Uranus and Neptune, which have different compositions, as ice giants. Both names are potentially misleading; the Solar System's giant planets all consist primarily of fluids above their critical point (thermodynamics), critical points, where distinct gas and liquid phases do not exist. Jupiter and Saturn are princip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined and slightly less than one-thousandth the mass of the Sun. Its diameter is 11 times that of Earth and a tenth that of the Sun. Jupiter orbits the Sun at a distance of , with an orbital period of . It is the List of brightest natural objects in the sky, third-brightest natural object in the Earth's night sky, after the Moon and Venus, and has been observed since prehistoric times. Its name derives from that of Jupiter (god), Jupiter, the chief deity of ancient Roman religion. Jupiter was the first of the Sun's planets to form, and its inward migration during the primordial phase of the Solar System affected much of the formation history of the other planets. Jupiter's atmosphere consists of 76% hydrogen and 24% helium by mass, with a denser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
