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HD 142415
HD 142415 is a single star in the southern constellation of Norma, positioned next to the southern constellation border with Triangulum Australe and less than a degree to the west of NGC 6025. With an apparent visual magnitude of 7.33, it is too faint to be visible to the naked eye. The distance to this star is 116 light years from the Sun based on parallax, but it is drifting closer with a radial velocity of −12 km/s. It is a candidate member of the NGC 1901 open cluster of stars. This is an ordinary G-type main-sequence star with a stellar classification of G1V. It has been identified as a solar twin by Datson et al. (2012), which means its physical properties are very similar to the Sun. It has 10% more mass than the Sun but only a 3% larger radius. The star is estimated to be 1.6 billion years old and is spinning with a projected rotational velocity of 4.2 km/s. It is radiating 1.16 times the luminosity of the Sun from its photosphere at an eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norma (constellation)
Norma is a small constellation in the Southern Celestial Hemisphere between Ara (constellation), Ara and Lupus (constellation), Lupus, one of twelve drawn up in the 18th century by France, French astronomer Nicolas-Louis de Lacaille and one of several depicting scientific instruments. Its name is Latin for T-square, normal, referring to a surface normal, right angle, and is variously considered to represent a Ruler, rule, a carpenter's square, a set square or a spirit level, level. It remains one of the 88 modern constellations. Four of Norma's brighter stars—Gamma, Delta, Epsilon and Eta—make up a square in the field of faint stars. Gamma2 Normae, Gamma2 Normae is the brightest star with an apparent magnitude of 4.0. Mu Normae is one of the most luminosity, luminous stars known, with a luminosity between a quarter million and one million times that of the Sun. Four star systems are known to harbour planets. The Milky Way, particularly the Norma Arm of the galaxy, passes ... [...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 corresponds almost exactly to a bolometric absolute magnitude of +4.74. 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 constant). Slow changes in the axial tilt of the planet and the shape of its orbit cause cyclical changes to the solar irradiance. The result is orbital forcing that causes the Milankovitch cycles, which determine Earthl ... [...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, published by the Bonn Observatory in Germany from 1859 to 1863, with an extension published in Bonn in 1886. 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 spectrum, electromagnetic wavelengths shorter or longer than visible light waves. Original catalog The Bonner Durchmusterung (abbreviated BD), was initiated by Friedrich Wilhelm Argelander, Friedrich Argelander and using observations largely carried out by his assistants, which resulted in a catalogue of the positions and apparent magnitudes of 342,198 stars down to approximate apparent magnitude 9.5 and covering the sky from 90°N to 2°S declination. The cat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Systems With One Confirmed Planet
Planetary means relating to a planet 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 An epicyclic gear train (also known as a planetary gearset) is a gear reduction assembly consisting of two gears mounted so that the center of one gear (the "planet") revolves around the center of the other (the "sun"). A carrier connects the ... (planetary gearing), an automotive transmission te ... [...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, main-sequence star (luminosity class V) of stellar classification, spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective temperature between about . Like other main-sequence stars, a G-type main-sequence star converts the Chemical element, element hydrogen to helium in its core by means of nuclear fusion. 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), Mass–energy equivalence, 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, and 51 Pegasi. Description Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Extrasolar Planets
A list is a set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of the list-maker, but lists are frequently written down on paper, or maintained electronically. Lists are "most frequently a tool", and "one does not ''read'' but only ''uses'' a list: one looks up the relevant information in it, but usually does not need to deal with it as a whole".Lucie Doležalová,The Potential and Limitations of Studying Lists, in Lucie Doležalová, ed., ''The Charm of a List: From the Sumerians to Computerised Data Processing'' (2009). Purpose It has been observed that, with a few exceptions, "the scholarship on lists remains fragmented". David Wallechinsky, a co-author of '' The Book of Lists'', described the attraction of lists as being "because we live in an era of overstimulation, especially in terms of information, and lists help us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 142022
HD 142022 is a binary star system located in the southernmost constellation of Octans. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 7.70. The distance to this system is based on stellar parallax, parallax, but it is drifting closer to the Sun with a radial velocity of −10 km/s. The primary, designated component A, is an old, Population I G-type star with a stellar classification of G9IV-V, showing a stellar spectrum, spectrum with mixed traits of a main sequence and a subgiant star. It is an estimated 7.6 billion years old and is spinning with a projected rotational velocity of 2 km/s. The star has similar mass and dimensions as the Sun, but has a 55% higher metallicity. It is radiating 89% of the luminosity of the Sun from its photosphere at an effective temperature of 5516 K. The magnitude 11.19 companion has the designation LTT 6384 and appears gravitationally bound to the primary. The pair have an angular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 141937
HD 141937 is a star in the southern zodiac constellation of Libra, positioned a couple of degrees to the north of Lambda Librae. It is a yellow-hued star with an apparent visual magnitude of 7.25, which means it is too faint to be seen with the naked eye. This object is located at a distance of 108.9 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −2.2 km/s. It has an absolute magnitude of 4.71. This is a G-type main-sequence star with a stellar classification of G1V. It is a solar-type star with slightly higher mass and radius compared to the Sun. The metallicity is higher than solar. It is an estimated 3.8 billion years old and is spinning with a projected rotational velocity of 6 km/s. The star is radiating 1.2 times the luminosity of the Sun from its photosphere at an effective temperature of 5,890 K. The star has a substellar companion (HD 141937 b) announced in April 2001 by the European South ... [...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: * Elliptic orbit: * Parabolic trajectory: * Hyperbolic trajectory: The eccentricity is given by e = \sqrt where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Velocity Method
Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star. As of June 2025, over 1,100 known extrasolar planets (about 19.0% of the total) have been discovered using Doppler spectroscopy. History Otto Struve proposed in 1952 the use of powerful spectrographs to detect distant planets. He described how a very large planet, as large as Jupiter, for example, would cause its parent star to wobble slightly as the two objects orbit around their center of mass. He predicted that the small Doppler shifts to the light emitted by the star, caused by its continuously varying radial velocity, would be detectable by the most sensitive spectrographs as tiny redshifts and blueshifts in the star's emission. However, the technology of the time produced radial-velocity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 142415 B
HD 142415 b is an exoplanet with the semi-amplitude of 51.3 ± 2.3 m/s. This indicates the minimum mass of 1.69 Jupiter mass, an orbital period of 386.3 days, and the semi-major axis of 1.07 astronomical units based from its stellar mass. The wild, oval pathed wobble of the star used by Doppler spectrometer indicates that the orbit of the planet is highly eccentric at around 50%. The planet was discovered in La Silla Observatory on 30 June 2003 by Mayor In many countries, a mayor is the highest-ranking official in a Municipal corporation, municipal government such as that of a city or a town. Worldwide, there is a wide variance in local laws and customs regarding the powers and responsibilitie ..., who used the CORALIE spectrograph. See also * HD 10647 b * HD 111232 b * HD 141937 b * HD 142022 Ab * HD 169830 c * HD 216770 b * HD 41004 Ab * HD 65216 b References External links * Exoplanets discovered in 2003 Giant planets Norma (constellation) Exopl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planet
A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets by the most restrictive definition of the term: the terrestrial planets Mercury (planet), Mercury, Venus, Earth, and Mars, and the giant planets Jupiter, Saturn, Uranus, and Neptune. 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 young protostar orbited by a protoplanetary disk. Planets grow in this disk by the gradual accumulation of material driven by gravity, a process called accretion (astrophysics), accretion. The word ''planet'' comes from the Greek () . In Classical antiquity, antiquity, this word referred to the Sun, Moon, and five points of light visible to the naked eye that moved across the background of the stars—namely, Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
