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TRAPPIST-1g
TRAPPIST-1g, also designated as 2MASS J23062928-0502285 g and K2-112 g, is an exoplanet orbiting around the ultra-cool dwarf star TRAPPIST-1, located away from Earth in the constellation Aquarius. It was one of four new exoplanets to be discovered orbiting the star in 2017 using observations from the Spitzer Space Telescope. The exoplanet is within the optimistic habitable zone of its host star. It was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. The second most distant known planet in its system, TRAPPIST-1g is a planet somewhat larger than Earth and with a similar density, meaning it is likely a rocky planet. Physical characteristics Mass, radius, and temperature TRAPPIST-1g has a radius of and a mass of , with a density only slightly less than Earth's, though initial estimates suggested its density was only 4.186 g/cm3, about 76% of Earth's. Based on mass-radius calculations and it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Extrasolar Candidates For Liquid Water
Extraterrestrial liquid water in the Solar System is likely uncommon, although it has been hypothesized to exist in some of its moons, and to have formerly existed on Mars and Venus.Owen, (2007)news.nationalgeographic.com/news/2007/11/071128-venus-earth_2.html Extrasolar liquid water has not yet been confirmed to exist. The following list contains candidates that meet the following criteria: * Confirmed object of Earth mass or greater orbiting within a circumstellar habitable zone (CHZ) * May not be a star * Has been studied for more than a year * Confirmed surface with strong evidence for it being either solid or liquid * Water vapour detected in its atmosphere * Gravitational, radio or differentation models predict a wet stratum Most known extrasolar planetary systems appear to have very different compositions from the Solar System, though there is sampling bias arising from the detection methods. The goal of current searches is to find Earth-sized planets in the habit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAPPIST-1e
TRAPPIST-1e, also designated as 2MASS J23062928-0502285 e, is a rocky, close-to-Earth-sized exoplanet orbiting within the habitable zone around the ultracool dwarf star TRAPPIST-1 approximately away from Earth in the constellation of Aquarius. Astronomers found the exoplanet by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. The exoplanet was one of seven new exoplanets discovered orbiting the star using observations from the Spitzer Space Telescope. Three of the seven (''e'', ''f'', and ''g'') are in the habitable zone. TRAPPIST-1e is similar to Earth's mass, radius, density, gravity, temperature, and stellar flux. It is also confirmed to not have a cloud-free hydrogen-dominated atmosphere, meaning it is more likely to have a compact atmosphere like the terrestrial planets in our solar system. In November 2018, researchers determined that of the seven exoplanets in the multi-planetary system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Nearest Terrestrial Exoplanet Candidates
This list of nearest terrestrial exoplanet candidates contains possible Terrestrial planet, terrestrial ("rocky") exoplanets spaced at a distance of up to 50 light-years from the Solar System, ordered by increasing distance. They may be composed primarily of silicate Rock (geology), rocks and/or metals. Within the Solar System, the terrestrial planets are the Solar System#Inner planets, inner planets closest to the Sun. Exoplanets discovered (incomplete) This list is incomplete, currently containing 34 exoplanets, 11 of which probably lie inside their star's habitable zone. There are roughly 2,000 stars at a distance of up to 50 light-years from the Solar System (64 of them are yellow-orange Stellar classification, "G" stars like our sun). As many as 15% of them could have Earth-sized planets in the habitable zones. On November 4, 2013, astronomers reported, based on Kepler space telescope, ''Kepler'' space mission data, that there could be as many as 40 billion Terrestrial pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Potentially Habitable Exoplanets
This is a list of potentially habitable exoplanets. The list is mostly based on estimates of habitability by the Habitable Exoplanets Catalog (HEC), and data from the NASA Exoplanet Archive. The HEC is maintained by the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. There is also a speculative list being developed of superhabitable planets. Surface planetary habitability is thought to require orbiting at the right distance from the host star for liquid surface water to be present, in addition to various geophysical and geodynamical aspects, atmospheric density, radiation type and intensity, and the host star's plasma environment. List This is a list of exoplanets within the circumstellar habitable zone that are under 10 Earth masses and smaller than 2.5 Earth radii, and thus have a chance of being rocky. Note that inclusion on this list does not guarantee habitability, and in particular the larger planets are unlikely to have a rocky composition. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spitzer Space Telescope
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, following IRAS (1983) and ISO (1995–1998). It was the first spacecraft to use an Earth-trailing orbit, later used by the Kepler planet-finder. The planned mission period was to be 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard liquid helium supply was exhausted. This occurred on 15 May 2009. Without liquid helium to cool the telescope to the very low temperatures needed to operate, most of the instruments were no longer usable. However, the two shortest-wavelength modules of the IRAC camera continued to operate with the same sensitivity as before the helium was exhausted, and continued to be used into early 2020 in the Spitzer Warm Mission. During the warm mission, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallicity
In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a convenient short term for ''"all elements except hydrogen and helium"''. This word-use is distinct from the conventional chemical or physical definition of a metal as an electrically conducting solid. Stars and nebulae with relatively high abundances of heavier elements are called "metal-rich" in astrophysical terms, even though many of those elements are nonmetals in chemistry. The presence of heavier elements hails from stellar nucleosynthesis, where the majority of elements heavier than hydrogen and helium in the Universe (''metals'', hereafter) are formed in the cores of stars as they evolve. Over time, stellar winds and supernovae deposit the metals into the surrounding environment, enriching the interstellar medium and providing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAPPIST-1d
TRAPPIST-1d, also designated as 2MASS J23062928-0502285 d, is a small exoplanet (about 30% the mass of the Earth), which orbits on the inner edge of the habitable zone of the ultracool dwarf star TRAPPIST-1 approximately 40 light-years (12.1 parsecs, or nearly km) away from Earth in the constellation of Aquarius. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. The first signs of the planet were announced in 2016, but it wasn't until the following years that more information concerning the probable nature of the planet was obtained. TRAPPIST-1d is the least massive planet of the system and is likely to have a compact hydrogen-poor atmosphere similar to Venus, Earth, or Mars. It receives just 4.3% more sunlight than Earth, placing it on the inner edge of the habitable zone. It has about <5% of its mass as a volatile layer, which could consist of atmosphere, oceans, and/or ice lay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Transiting Exoplanets
This is the list of 232 transiting extrasolar planets sorted by orbital periods. All the transiting planets have true masses, radii and most have known inclinations. Radius is determined by how much the star dims during the transit and inclination is determined from Rossiter–McLaughlin effect. True mass is determined by the minimum mass determined from radial velocity observations divided by the sine of inclination. The first known planet to be discovered with the transit method was OGLE-TR-56b. The first planetary transit observed (by already known exoplanet) was caused by HD 209458 b. The most massive transiting exoplanet is KELT-1b which masses 27.23 MJ (making it a brown dwarf) while the least massive is Kepler-42d which masses less than 0.003 MJ or 0.9 M🜨. The largest exoplanet known is HAT-P-32b which is 2.037 RJ. The smallest exoplanet known is also Kepler-42d which is 0.051 RJ or 0.57 R🜨. The densest transiting exoplanet known is COROT-3b, which has density of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAPPIST-1f
TRAPPIST-1f, also designated as 2MASS J23062928-0502285 f, is an exoplanet, likely rocky, orbiting within the habitable zone around the ultracool dwarf star TRAPPIST-1, located away from Earth in the constellation of Aquarius. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. It was one of four new exoplanets to be discovered orbiting the star in 2017 using observations from the Spitzer Space Telescope. The planet is likely tidally locked, and has been depicted as an eyeball planet in artistic impressions by NASA. Physical characteristics Mass, radius, and temperature TRAPPIST-1f is an Earth-sized exoplanet, meaning it has a radius close to that of Earth. It has an equilibrium temperature of . It has a radius of and a mass of . It was initially estimated to have a much lower mass, and thus a low density of and a surface gravity around (62% of Earth's value). This sugge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAPPIST-1h
TRAPPIST-1h, also designated as 2MASS J23062928-0502285 h, is an exoplanet orbiting around the ultra-cool dwarf star TRAPPIST-1 39 light-years (12 parsecs) away from Earth in the constellation Aquarius. It was one of four new exoplanets to be discovered orbiting the star using observations from the Spitzer Space Telescope. Throughout 2017 and 2018, more studies were able to refine its physical parameters. The outermost known planet in its system, it is roughly one third the mass of Earth, and about 77% as large. Its relatively low density indicates that it is likely water-rich, like several other planets in the system. Physical characteristics Mass, radius, and temperature TRAPPIST-1h has a radius of 0.773 , a mass of 0.331 , and about 56% Earth's surface gravity. It has a density of 3.97 g/cm3, extremely similar to that of Mars. Given this density, about ≤5% of its mass must be water, likely in the form of a thick ice shell, seeing as it only receives about 13% of the ... [...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] |
Astronomical Unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits the Sun, from a maximum (aphelion) to a minimum (perihelion) and back again once each year. The astronomical unit was originally conceived as the average of Earth's aphelion and perihelion; however, since 2012 it has been defined as exactly (see below for several conversions). The astronomical unit is used primarily for measuring distances within the Solar System or around other stars. It is also a fundamental component in the definition of another unit of astronomical length, the parsec. History of symbol usage A variety of unit symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union (IAU) had used the symbol ''A'' to denote a length equal to the astronomical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
