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Mega Earth
A mega-Earth is a proposed neologism for a massive terrestrial exoplanet that is at least ten times the mass of Earth. Mega-Earths would be substantially more massive than super-Earths (terrestrial and ocean planets with masses around 5–10 Earths). The term "mega-Earth" was coined in 2014, when Kepler-10c was revealed to be a Neptune-mass planet with a density considerably greater than that of Earth, though it has since been determined to be a typical volatile-rich planet weighing just under half that mass. Examples Kepler-10c was the first exoplanet to be classified as a mega-Earth. At the time of its discovery, it was believed to have a mass around 17 times that of Earth () and a radius around 2.3 times Earth's (), giving it a high density that implied a mainly rocky composition. However, several follow-up radial velocity studies produced different results for Kepler-10c's mass, all much below the original estimate. In 2017, a more careful analysis using data from multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanet Comparison Kepler-10 C
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] |
Neologism
A neologism Greek νέο- ''néo''(="new") and λόγος /''lógos'' meaning "speech, utterance"] is a relatively recent or isolated term, word, or phrase that may be in the process of entering common use, but that has not been fully accepted into mainstream language. Neologisms are often driven by changes in culture and technology. In the process of language formation, neologisms are more mature than '' protologisms''. A word whose development stage is between that of the protologism (freshly coined) and neologism (new word) is a ''prelogism''. Popular examples of neologisms can be found in science, fiction (notably science fiction), films and television, branding, literature, jargon, cant, linguistics, the visual arts, and popular culture. Former examples include ''laser'' (1960) from Light Amplification by Stimulated Emission of Radiation; ''robot'' (1941) from Czech writer Karel Čapek's play ''R.U.R. (Rossum's Universal Robots)''; and ''agitprop'' (1930) (a portmanteau of " ... [...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] |
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super-Earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively. The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or habitability. The alternative term "gas dwarfs" may be more accurate for those at the higher end of the mass scale, although "mini-Neptunes" is a more common term. Definition In general, super-Earths are defined by their masses, and the term does not imply temperatures, compositions, orbital properties, habitability, or environments. While sources generally agree on an upper bound of 10 Earth masses (~69% of the mass of Uranus, which is the Solar System's giant planet with the least mass), the lower bound varies from 1 or 1.9 to 5, with various other definitions appearing in the popular media. The term "super-Earth" is also used by astronomers to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-10c
Kepler-10c is an exoplanet orbiting the G-type star Kepler-10, located around 608 light-years away in Draco. Its discovery was announced by Kepler in May 2011, although it had been seen as a planetary candidate since January 2011, when Kepler-10b was discovered. The team confirmed the observation using data from NASA's Spitzer Space Telescope and a technique called BLENDER that ruled out most false positives. Kepler-10c was the third transiting planet to be confirmed statistically (based on probability rather than actual observation), after Kepler-9d and Kepler-11g. The Kepler team considers the statistical method that led to the discovery of Kepler-10c as what will be necessary to confirm many planets in Kepler's field of view. Kepler-10c orbits its host star every forty-five days at a quarter of the average distance between the Sun and Earth. Initial observations showed that it has a radius more than double that of Earth, and suggested a higher density, suggesting a mainly r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mini-Neptune
A Mini-Neptune (sometimes known as a gas dwarf or transitional planet) is a planet less massive than Neptune but resembling Neptune in that it has a thick hydrogen–helium atmosphere, probably with deep layers of ice, rock or liquid oceans (made of water, ammonia, a mixture of both, or heavier volatiles). A gas dwarf is a gas planet with a rocky core that has accumulated a thick envelope of hydrogen, helium, and other volatiles, having, as a result, a total radius between 1.7 and 3.9 Earth radii (). The term is used in a three-tier, metallicity-based classification regime for short-period exoplanets, which also includes the rocky, terrestrial-like planets with less than and planets greater than , namely ice giants and gas giants. Properties Theoretical studies of such planets are loosely based on knowledge about Uranus and Neptune. Without a thick atmosphere, it would be classified as an ocean planet instead. An estimated dividing line between a rocky planet and a gaseous pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BD+20594b
BD+2 0594b (also known as K2-56b) is a massive exoplanet discovered by the Kepler spacecraft in collaboration with the HARPS spectrometer at La Silla in Chile. Naming BD+20 594b indicates that the planet circles a star found in the Bonner Durchmusterung catalogue, ''BD +20° 594'', the 594th entry in the +20-degree zone (declinations from +19 to +20 degrees); and that it is the first planet discovered orbiting that star. K2-56b indicates that the planet circles a star catalogued in the Kepler 2 mission catalogue (part of the extended K2 Kepler mission), the 56th one in the catalogue; and that it is the first planet discovered orbiting that star. Planet With a radius of 2.2 R🜨 and a mass of 16.31 M🜨, BD+20594b is substantially smaller than Neptune. Taking the estimates of its radius and mass at face value, the composition of the planet would be rocky, hence making it classified as a mega-Earth. BD+20594b's exact composition is still unknown. The planet was discovered on Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
K2-66b
K2-66b is a confirmed mega-Earth orbiting the subgiant K2-66, about form Earth in the direction of Aquarius. It is an extremely hot and dense planet heavier than Neptune, but with only about half its radius. Planet properties Mass, radius, and temperature K2-66b is a mega-Earth with radius and mass . The planet's temperature is highly variable due to the variability of its host star, and is currently estimated at . Orbit The planet orbits every 5.07 days at 0.06 AU. It orbits within a "photoevaporation desert", where orbiting exoplanets should be very uncommon. K2-66b's orbit is nearly circular. Star The star, K2-66 is a G1 sub-giant in Aquarius. It has a sun-like temperature of 5887 K, which corresponds to its spectral class and is very close to that of throtationally variablestaKepler-130 It has a radius of and a mass of . Its metallicity is −0.047, and its apparent magnitude is 11.71. See also * Kepler * Mega-Earth * K2-56b * Sub-giant *G-type main se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-277b
Kepler-277b (also known by its Kepler Objects of Interest designation KOI-1215.01) is the second most massive and third-largest rocky planet ever discovered, with a mass close to that of Saturn. Discovered in 2014 by the Kepler Space Telescope, Kepler-277b is a sub-Neptune sized exoplanet with a very high mass and density for an object of its radius, suggesting a composition made mainly of rock and iron. Along with its sister planet, Kepler-277c, the planet's mass was determined using transit-timing variations (TTVs). Characteristics Size and temperature Kepler-277b was detected using the transit method and TTVs, allowing for both its mass and radius to be determined to some level. It is approximately 2.92 , between the size of Earth and Neptune. At that radius, most planets should be gaseous Mini-Neptunes with no solid surface. However, the mass of Kepler-277b is extremely high for its size. Transit-timing variations indicate a planetary mass of about 87.3 , comparable to Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-277c
Kepler-277c (also known by its Kepler Objects of Interest designation KOI-1215.02) is the third most massive and second-largest rocky planet ever discovered, with a mass about 64 times that of Earth. Discovered in 2014 by the Kepler Space Telescope, Kepler-277c is a Neptune-sized exoplanet with a very high mass and density for an object of its radius, suggesting a composition made mainly of rock with some amounts of water. Along with its sister planet, Kepler-277b, the planet's mass was determined using transit-timing variations (TTVs). Characteristics Size and temperature Kepler-277c was detected using the transit method and TTVs, allowing for both its mass and radius to be determined to some level. It is approximately 3.36 , close to the size of Neptune. At that radius, most planets should be gaseous Mini-Neptunes with no solid surface. However, the mass of Kepler-277c is extremely high for its size. Transit-timing variations indicate a planetary mass of about 64.2 , close to S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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