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HD 117618
HD 117618, named Dofida by the IAU, is a single, yellow-hued star in the southern constellation of Centaurus. With an apparent visual magnitude of 7.17, it is too faint to be visible to the naked eyes of a typical observer. The distance to this star, as determined from its annual parallax shift of as seen from Earth's orbit, is about 124 light years. It is moving further away with a heliocentric radial velocity of around +1.6 km/s. This star is similar to the Sun, being a G-type main-sequence star with a stellar classification of G0 V. It is about 10% more massive and 17% larger than the Sun, with an estimated age of roughly four billion years and a projected rotational velocity of 3.67 km/s. The star is radiating 1.6 times the Sun's luminosity from its photosphere at an effective temperature of 6,019 K. Name HD 117618, and its planet HD 117618b, were chosen as part of the 2019 NameExoWorlds campaign organised by the International Astronom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 117618 B
HD 117618 b, named Noifasui by the IAU, is an exoplanet discovered orbiting the star HD 117618 in September 2004. The planet is a small gas giant less than a fifth the mass of Jupiter. It orbits close to its star in a very eccentric orbit. Name The planet was originally named "HD 117618 b", being the second object in the HD 117618 system. It was given the name "Noifasui" by the IAU, chosen by Indonesian representatives for the NameExoWorlds NameExoWorlds (also known as IAU NameExoWorlds) is the name of various projects managed by the International Astronomical Union (I.A.U.) to encourage names to be submitted for astronomical objects, which would later be considered for official ad ... campaign, meaning ''revolve around'' in Nias language (derived from the word ''ifasui'', meaning ''to revolve around'', and ''no'', indicating that the action occurred in the past and continued to the present time). Its parent star was simultaneously named "Dofida" in the contest. References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaurus
Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. In Greek mythology, Centaurus represents a centaur; a creature that is half human, half horse (another constellation named after a centaur is one from the zodiac: Sagittarius). Notable stars include Alpha Centauri, the nearest star system to the Solar System, its neighbour in the sky Beta Centauri, and V766 Centauri, one of the largest stars yet discovered. The constellation also contains Omega Centauri, the brightest globular cluster as visible from Earth and the largest identified in the Milky Way, possibly a remnant of a dwarf galaxy. Notable features Stars Centaurus contains several very bright stars. Its alpha and beta stars are used as "pointer stars" to help observers find the constellation Crux. Centaurus has 281 stars above ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nias Language
The Nias language is an Austronesian language spoken on Nias Island and the Batu Islands off the west coast of Sumatra in Indonesia. It is known as Li Niha by its native speakers. It belongs to the Northwest Sumatra–Barrier Islands subgroup which also includes Mentawai and the Batak languages. It had about 770,000 speakers in 2000. There are three main dialects: northern, central and southern. It is an open-syllable language, which means there are no syllable-final consonants. Dialects Nias is typically considered to have three dialects.Ethnologue *Northern dialect: particularly the Gunungsitoli variety, Alasa and Lahewa area. *South dialect: South Nias, Gomo Area, Telukdalam Area and Batu Islands. *Central dialect: West Nias, particularly in Sirombu and Mandrehe areas. Cognate percentage among the dialects of Nias is about 80%. The northern variant is considered the prestige dialect. The only complete Bible translation is written in the northern dialect and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Durchmusterung Objects
In astronomy, Durchmusterung or Bonner Durchmusterung (BD) is an astrometric star catalogue of the whole sky, compiled by the Bonn Observatory in Germany from 1859 to 1903. The name comes from ('run-through examination'), a German word used for a systematic survey of objects or data. The term has sometimes been used for other astronomical surveys, including not only stars, but also the search for other celestial objects. Special tasks include celestial scanning in electromagnetic wavelengths shorter or longer than visible light waves. Original catalog The 44 years of work on the Bonner Durchmusterung (abbreviated BD), initiated by Friedrich Argelander and largely carried out by his assistants, resulted in a catalogue of the positions and apparent magnitudes of approximately 325,000 stars to apparent magnitude 9–10. The catalogue was accompanied by charts plotting the positions of the stars, and was the basis for the ''Astronomische Gesellschaft Katalog'' (AGK) and '' Smith ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Systems With One Confirmed Planet
Planetary means relating to a planet A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a ... or planets. It can also refer to: ;Science * Planetary habitability, the measure of an astronomical body's potential to develop and sustain life * Planetary nebula, an astronomical object ;People * Planetary (rapper), one half of east coast rap group OuterSpace ;Arts, entertainment, and media * ''Planetary'' (comics), a comic book series by Warren Ellis and John Cassaday * " Planetary (Go!)", a 2011 song by rock band My Chemical Romance * '' Planetary Radio'', a public radio show about space exploration, produced by The Planetary Society ;Organizations * The Planetary Society, the Earth's largest space interest group ;Technology * Epicyclic gearing (planetary gearing), an automotive tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-type Main-sequence Stars
A G-type main-sequence star (Spectral type: G-V), also often, and imprecisely called a yellow dwarf, or G star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective temperature between about 5,300 and 6,000 K. Like other main-sequence stars, a G-type main-sequence star is converting the element hydrogen to helium in its core by means of nuclear fusion, but can also fuse helium when hydrogen runs out. The Sun, the star in the center of the Solar System to which the Earth is gravitationally bound, is an example of a G-type main-sequence star (G2V type). Each second, the Sun fuses approximately 600 million tons of hydrogen into helium in a process known as the proton–proton chain (4 hydrogens form 1 helium), converting about 4 million tons of matter to energy. Besides the Sun, other well-known examples of G-type main-sequence stars include Alpha Centauri, Tau Ceti, Capella and 51 Pegasi. The term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Astronomical Journal
''The Astronomical Journal'' (often abbreviated ''AJ'' in scientific papers and references) is a peer-reviewed monthly scientific journal owned by the American Astronomical Society (AAS) and currently published by IOP Publishing. It is one of the premier journals for astronomy in the world. Until 2008, the journal was published by the University of Chicago Press on behalf of the AAS. The reasons for the change to the IOP were given by the society as the desire of the University of Chicago Press to revise its financial arrangement and their plans to change from the particular software that had been developed in-house. The other two publications of the society, the ''Astrophysical Journal'' and its supplement series, followed in January 2009. The journal was established in 1849 by Benjamin A. Gould. It ceased publication in 1861 due to the American Civil War, but resumed in 1885. Between 1909 and 1941 the journal was edited in Albany, New York. In 1941, editor Benjamin Boss arrange ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Extrasolar Planets
These are lists of exoplanets. Most of these were discovered by the Kepler space telescope. There are an additional 2,054 potential exoplanets from Kepler's first mission yet to be confirmed, as well as 978 from its " Second Light" mission and 4,081 from the Transiting Exoplanet Survey Satellite (TESS) mission. For yearly lists on physical, orbital and other properties, as well as on discovery circumstances and other aspects, ''see ''. Nomenclature Methods of detection Specific exoplanet lists Lists of exoplanets *List of directly imaged exoplanets * List of exoplanets discovered before 2000 () * List of exoplanets discovered between 2000–2009 () * List of exoplanets discovered in 2010 () * List of exoplanets discovered in 2011 () *List of exoplanets discovered in 2012 () * List of exoplanets discovered in 2013 () * List of exoplanets discovered in 2014 () *List of exoplanets discovered in 2015 () *List of exoplanets discovered in 2016 () *List of exoplanets discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 117207
HD 117207 is a star in the southern constellation Centaurus. With an apparent visual magnitude of 7.24, it is too dim to be visible to the naked eye but can be seen with a small telescope. Based upon parallax measurements, it is located at a distance of from the Sun. The star is drifting closer with a radial velocity of −17.4 km/s. It has an absolute magnitude of 4.67. This object has a stellar classification of G7IV-V, showing blended spectral traits of a G-type main-sequence star and an older, evolving subgiant star. It is around four billion years old with 5% greater mass than the Sun and a 7% larger radius. The star is radiating 1.16 times the luminosity of the Sun from its photosphere at an effective temperature of 5,644 K. In 2005, a planet was found orbiting the star using the radial velocity method, and was designated HD 117207 b. The orbital elements of this planet were refined in 2018, showing an orbital period of , a semimajor axis o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Bound
In mathematics, particularly in order theory, an upper bound or majorant of a subset of some preordered set is an element of that is greater than or equal to every element of . Dually, a lower bound or minorant of is defined to be an element of that is less than or equal to every element of . A set with an upper (respectively, lower) bound is said to be bounded from above or majorized (respectively bounded from below or minorized) by that bound. The terms bounded above (bounded below) are also used in the mathematical literature for sets that have upper (respectively lower) bounds. Examples For example, is a lower bound for the set (as a subset of the integers or of the real numbers, etc.), and so is . On the other hand, is not a lower bound for since it is not smaller than every element in . The set has as both an upper bound and a lower bound; all other numbers are either an upper bound or a lower bound for that . Every subset of the natural numbers has a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semimajor Axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the longest semidiameter or one half of the major axis, and thus runs from the centre, through a focus, and to the perimeter. The semi-minor axis (minor semiaxis) of an ellipse or hyperbola is a line segment that is at right angles with the semi-major axis and has one end at the center of the conic section. For the special case of a circle, the lengths of the semi-axes are both equal to the radius of the circle. The length of the semi-major axis of an ellipse is related to the semi-minor axis's length through the eccentricity and the semi-latus rectum \ell, as follows: The semi-major axis of a hyperbola is, depending on the convention, plus or minus one half of the distance between the two branches. Thus it is the distance from the cent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Eccentricity
In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit (or capture orbit), and greater than 1 is a hyperbola. The term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the Galaxy. Definition In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit. The eccentricity of this Kepler orbit is a non-negative number that defines its shape. The eccentricity may take the following values: * circular orbit: ''e'' = 0 * elliptic orbit: 0 < ''e'' < 1 * |
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