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81 Ceti
81 Ceti is a star located approximately 331 light years away from the Sun in the equatorial constellation of Cetus. ''81 Ceti'' is the Flamsteed designation for this object. It is visible to the naked eye as a dim, yellow-hued point of light with an apparent visual magnitude of 5.65. The star is drifting further away from the Earth with a heliocentric radial velocity of +9 km/s. This is an aging K-type giant star with a stellar classification of K0III, having exhausted the supply of hydrogen at its core and expanded to 11 times the Sun's radius. It is a red clump giant, which indicates it is on the horizontal branch and is generating energy from core helium fusion. The star is now 2.5 billion years old with 1.6 times the mass of the Sun. It is radiating 60 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,825 K. Planetary system In July 2008, the planet 81 Ceti b was announced by Sato and colla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flamsteed Designation
A Flamsteed designation is a combination of a number and constellation name that uniquely identifies most naked eye stars in the modern constellations visible from southern England. They are named for John Flamsteed who first used them while compiling his '' Historia Coelestis Britannica''. (Flamsteed used a telescope, and the catalog also includes some stars which are relatively bright but not necessarily visible with the naked eye.) Description Flamsteed designations for stars are similar to Bayer designations, except that they use numbers instead of Greek and Roman letters. Each star is assigned a number and the Latin genitive of the constellation it lies in (see 88 modern constellations for a list of constellations and the genitive forms of their names). Flamsteed designations were assigned to 2554 stars. The numbers were originally assigned in order of increasing right ascension within each constellation, but due to the effects of precession they are now slightly out of o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminosity Of The Sun
The solar luminosity (), is a unit of radiant flux (power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun. One nominal solar luminosity is defined by the International Astronomical Union to be . This does not include the solar neutrino luminosity, which would add , or , i.e. a total of (the mean energy of the solar photons is 26 MeV and that of the solar neutrinos 0.59 MeV, i.e. 2.27%; the Sun emits photons and as many neutrinos each second, of which per m2 reach the Earth each second). The Sun is a weakly variable star, and its actual luminosity therefore fluctuates. The major fluctuation is the eleven-year solar cycle (sunspot cycle) that causes a quasi-periodic variation of about ±0.1%. Other variations over the last 200–300 years are thought to be much smaller than this. Determination Solar luminosity is related to solar irradiance (the solar c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lists Of Exoplanets
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 discovered in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 167042
HD 167042 is a 6th magnitude K-type subgiant star located approximately 164 light-years away in Draco constellation. It has mass of 1.88 times that of the Sun and the age is only 1.8 billion years old. When this star was a main sequence, it was white mid to late A-type star based on its mass. Planetary system On 28 November 2007, a preprint of the discovery of the planet HD 167042 b was posted to the arXiv server. The peer reviewed paper was then published in The Astrophysical Journal on 1 March 2008. The discovery was later independently confirmed. See also * HD 16175 * Kappa Coronae Borealis * 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 ... References External links * {{Stars of Draco Draco (constellation) 167042 08 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
94 Ceti
94 Ceti (HD 19994) is a trinary star system approximately 73 light-years away in the constellation Cetus. 94 Ceti A is a yellow-white dwarf star with about 1.3 times the mass of the Sun while 94 Ceti B and C are red dwarf stars. An infrared excess has been detected around the primary, most likely indicating the presence of a circumstellar disk at a radius of 95 AU. The temperature of this dust is 40 K. Stellar system This system is a hierarchical triple star system with 94 Ceti A being orbited by 94 Ceti BC, a pair of M dwarfs, in 2000 years. 94 Ceti B and C meanwhile orbit each other in a 1-year orbit. Planetary system On 7 August 2000, a planet was announced by the Geneva Extrasolar Planet Search team as a result of radial velocity measurements taken with the Swiss 1.2-metre Leonhard Euler Telescope at La Silla Observatory in Chile. It is most stable if its inclination is either 65 or 115, ± 3. See also * 79 Ceti * 81 Ceti * Lists of exop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
79 Ceti
79 Ceti, also known as ''HD 16141'', is a binary star system located 123 light-years from the Sun in the southern constellation of Cetus. It has an apparent visual magnitude of +6.83, which puts it below the normal limit for visibility with the average naked eye. The star is drifting closer to the Earth with a heliocentric radial velocity of −51 km/s. Harlan (1974) assigned this star a stellar classification of G2V, matching an ordinary G-type main-sequence star that is undergoing core hydrogen fusion. However, Houk and Swift (1999) found a class of G8IV, which suggests it has exhausted the supply of hydrogen at its core and begun to evolve off the main sequence. Eventually the outer layers of the star will expand and cool and the star will become a red giant. Estimates of the star's age range from 6.0 to 9.4 billion years old. It has an estimated 1.06 times the mass of the Sun and 1.48 times the Sun's radius. The star is radiating twice luminosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6 Lyncis
6 Lyncis is a star in the northern constellation of Lynx, located approximately 179 light years from Earth. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.86. This object is moving away from the Earth with a heliocentric radial velocity of +40 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.341 arc seconds per annum. This is an aging giant star with a stellar classification of , which indicates it has a mild overabundance of iron in its spectrum. At the age of 2.8 billion years old, it has exhausted the hydrogen at its core, causing it to evolve away from the main sequence. As a consequence, it has expanded to 5.2 times the radius of the Sun although it only has 1.46 times the Sun's mass. The star is radiating 14.9 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,994 K. One sub-stellar companion has been identifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
14 Andromedae
14 Andromedae, abbreviated 14 And, also named Veritate , is a single, orange-hued giant star situated approximately 247 light-years away in the northern constellation of Andromeda. It is dimly visible to the naked eye with an apparent visual magnitude of 5.22. The star is moving closer to the Earth with a heliocentric radial velocity of −60 km/s. In 2008 an extrasolar planet (designated 14 Andromedae b, later named ''Spe'') was discovered to be orbiting the star. This is a red clump giant with a stellar classification of K0 III, indicating it is on the horizontal branch and is generating energy through helium fusion at its core. The star has 1.12 (or 2.2) times the mass of the Sun and has expanded to 10.5 times the Sun's radius. It is radiating 60.3 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,743 K. It is thought it was formerly an A- or F-type main-sequence star earlier in its life, prior to evolvi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter Mass
Jupiter mass, also called Jovian mass, is the unit of mass equal to the total mass of the planet Jupiter. This value may refer to the mass of the planet alone, or the mass of the entire Jovian system to include the moons of Jupiter. Jupiter is by far the most massive planet in the Solar System. It is approximately 2.5 times as massive as all of the other planets in the Solar System combined. Jupiter mass is a common unit of mass in astronomy that is used to indicate the masses of other similarly-sized objects, including the outer planets, extrasolar planets, and brown dwarfs, as this unit provides a convenient scale for comparison. Current best estimates The current best known value for the mass of Jupiter can be expressed as : :M_\mathrm=(1.89813 \pm 0.00019)\times10^ \text, which is about as massive as the sun (is about ): :M_\mathrm=\frac M_ \approx (9.547919 \pm 0.000002) \times10^ M_. Jupiter is 318 times as massive as Earth: :M_\mathrm = 3.1782838 \times 10^2 M_\oplu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super-Jupiter
A super-Jupiter is a gas giant exoplanet that is more massive than the planet Jupiter. For example, companions at the planet–brown dwarf borderline have been called super-Jupiters, such as around the star Kappa Andromedae. By 2011 there were 180 known super-Jupiters, some hot, some cold. Even though they are more massive than Jupiter, they remain about the same size as Jupiter up to 80 Jupiter masses. This means that their surface gravity and density go up proportionally to their mass. The increased mass compresses the planet due to gravity, thus keeping it from being larger. In comparison, planets somewhat lighter than Jupiter can be larger, so-called "puffy planets" (gas giants with a large diameter but low density). An example of this may be the exoplanet HAT-P-1b with about half the mass of Jupiter but about 1.38 times larger diameter. CoRoT-3b, with a mass around 22 Jupiter masses, is predicted to have an average density of 26.4 g/cm3, greater than osmium (22.6 g/cm3), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6 Lyncis B
6 Lyncis b (abbreviated 6 Lyn b) is an extrasolar planet orbiting the K-type subgiant star 6 Lyncis which is approximately 182 light years away in the Lynx constellation. The planet has a minimum mass . The orbital period for this planet is 899 days, or 2.46 years. The orbital radius for this planet is 2.2 AU, periastron 1.9 AU, and apastron 2.5 AU, corresponding to the orbital eccentricity of 0.134. This planet was discovered on July 3, 2008 by Sato ''et al.'', who used Doppler spectroscopy to find variations of the line of sight motion of the star caused by the planet’s gravity during its orbit. See also * 14 Andromedae b * 41 Lyncis b 41 Lyncis b (abbreviated 41 Lyn b), also designated HD 81688 b and named Arkas , is an extrasolar planet approximately 280 light-years from Earth in the constellation of Ursa Major. A gas giant with a minimum mass 2.7 times that of Jupiter, it or ... * 81 Ceti b References External links * * Lynx (constellation) Giant plane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
14 Andromedae B
14 Andromedae b (abbreviated 14 And b), formally named Spe , is an exoplanet approximately 249 light years away in the constellation of Andromeda. The 186-day period planet orbits about 83% the Earth- Sun distance from the giant star 14 Andromedae. It has a minimum mass 4.8 times the mass of Jupiter. The planet orbits with an eccentricity of 0.0094, which means the orbital distance over the course of its revolution varies by only 0.02 AU. Nomenclature In July 2014 the International Astronomical Union launched NameExoWorlds, a process for giving proper names to certain exoplanets and their host stars. The process involved public nomination and voting for the new names. In December 2015, the IAU announced the name Spe for this planet. The winning name was based on that submitted by the Thunder Bay Centre of the Royal Astronomical Society of Canada); namely 'Spes', Latin for 'hope'. (Spes was also the Roman goddess of hope.) The IAU substituted the ablative form 'Spe', w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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