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HD 10180 C
HD 10180 c is an exoplanet approximately 130 light-years away in the constellation Hydrus. It was discovered in 2010 using the radial velocity method. With a minimum mass comparable to that of Neptune, it is of the class of planets known as Hot Neptune A hot Neptune or Hoptune is a type of giant planet with a mass similar to that of Uranus or Neptune orbiting close to its star, normally within less than 1 AU. The first hot Neptune to be discovered with certainty was Gliese 436 b in 2007, an exo ...s. Dynamical simulations suggest that if the mass gradient was any more than a factor of two, the system would not be stable. While planet c does not exist in any mean motion resonances, both planets with adjacent orbits (b and d) share near resonances with c. References Exoplanets discovered in 2010 Exoplanets detected by radial velocity Hydrus Hot Neptunes {{extrasolar-planet-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 10180
HD 10180, also designated 2MASS J01375356-6030414, is a Sun-like star in the southern constellation Hydrus that is notable for its large planetary system. Since its discovery, at least six exoplanets have been observed orbiting it, and some studies have proposed up to nine potential planets, which would make it potentially the largest of all known planetary systems, including the Solar System. Characteristics Based upon parallax measurements, it is located at a distance of from Earth. The apparent visual magnitude of this star is 7.33, which is too faint to be viewed with the naked eye although it can be readily observed with a small telescope. At a declination of −60°, this star cannot be seen at latitudes north of the tropics. HD 10180 is a G1V-type star, and thus generates energy at its core through the thermonuclear fusion of hydrogen. The mass of this star is estimated as 6% greater than the Sun's mass, it has a radius of 120% that of the Sun, and is radiating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanet
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. About 1 in 5 Sun-like starsFor the purpose of this 1 in 5 statistic, "Sun-like" means G-type star. Data for Sun-like stars was not available so this statistic is an extrapolation from data about K-type stars. have an "Earth-sized"For the purpose of this 1 in 5 statistic, Earth-sized means 1–2 Earth radii. planet in the habitable zone. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 (one million million, or billion in long scale). As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in a vacuum in one Julian year (365.25 days). Because it includes the time-measurement word "year", the term ''light-year'' is sometimes misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years) which derives from astrometry; it is the distance at which one astronomical unit subtends an angle of one second of arc. Defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrus
Hydrus is a small constellation in the deep southern sky. It was one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman and it first appeared on a 35-cm (14 in) diameter celestial globe published in late 1597 (or early 1598) in Amsterdam by Plancius and Jodocus Hondius. The first depiction of this constellation in a celestial atlas was in Johann Bayer's Uranometria of 1603. The French explorer and astronomer Nicolas Louis de Lacaille charted the brighter stars and gave their Bayer designations in 1756. Its name means "male water snake", as opposed to Hydra, a much larger constellation that represents a female water snake. It remains below the horizon for most Northern Hemisphere observers. The brightest star is the 2.8-magnitude Beta Hydri, also the closest reasonably bright star to the south celestial pole. Pulsating between magnitude 3.26 and 3.33, Gamma Hydri is a variable red giant 60 ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doppler Spectroscopy
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. 1,018 extrasolar planets (about 19.5% of the total) have been discovered using Doppler spectroscopy, as of November 2022. 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 meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times the mass of Earth, and slightly more massive than its near-twin Uranus. Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere. It is referred to as one of the solar system's two ice giant planets (the other one being Uranus). Being composed primarily of gases and liquids, it has no well-defined "solid surface". The planet orbits the Sun once every 164.8 julian year (astronomy), years at an average distance of . It is named after the Neptune (mythology), Roman god of the sea and has the astronomical symbol , representing Neptune's trident. Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Neptune
A hot Neptune or Hoptune is a type of giant planet with a mass similar to that of Uranus or Neptune orbiting close to its star, normally within less than 1 AU. The first hot Neptune to be discovered with certainty was Gliese 436 b in 2007, an exoplanet about 33 light years away. Recent observations have revealed a larger potential population of hot Neptunes in the Milky Way than was previously thought. Hot Neptunes may have formed either in situ or ex situ. General characteristics Because of their close proximity to their parent stars, hot Neptunes have a much greater rate and chance of transiting their star as seen from a farther outlying point, than planets of the same mass in larger orbits. This increases the chances of discovering them by transit-based observation methods. Transiting hot Neptunes include Gliese 436 b and HAT-P-11b. Gliese 436 b (also known as GJ 436b) was the first hot Neptune to be discovered with certainty in 2007. The exoplanet Dulcinea (or HD 160691 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Resonance
In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relationship is found between a pair of objects (binary resonance). The physical principle behind orbital resonance is similar in concept to pushing a child on a swing, whereby the orbit and the swing both have a natural frequency, and the body doing the "pushing" will act in periodic repetition to have a cumulative effect on the motion. Orbital resonances greatly enhance the mutual gravitational influence of the bodies (i.e., their ability to alter or constrain each other's orbits). In most cases, this results in an ''unstable'' interaction, in which the bodies exchange momentum and shift orbits until the resonance no longer exists. Under some circumstances, a resonant system can be self-correcting and thus stable. Examples are the 1:2:4 resonance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanets Discovered In 2010
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. About 1 in 5 Sun-like starsFor the purpose of this 1 in 5 statistic, "Sun-like" means G-type star. Data for Sun-like stars was not available so this statistic is an extrapolation from data about K-type stars. have an "Earth-sized"For the purpose of this 1 in 5 statistic, Earth-sized means 1–2 Earth radii. planet in the habitable zone.F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanets Detected By Radial Velocity
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. About 1 in 5 Sun-like starsFor the purpose of this 1 in 5 statistic, "Sun-like" means G-type star. Data for Sun-like stars was not available so this statistic is an extrapolation from data about K-type stars. have an "Earth-sized"For the purpose of this 1 in 5 statistic, Earth-sized means 1–2 Earth radii. planet in the habitable zone. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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