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TRAPPIST-1
, - ! style="background-color: #FFFFC0; text-align: center;" colspan="2", Characteristics , - style="vertical-align:top" ! style="text-align:left" , Evolutionary stage , Main sequence , - style="vertical-align:top" ! style="text-align:left" , Spectral type , M8V , - style="vertical-align:top" ! style="text-align:left" , Apparent magnitude (R) , , - style="vertical-align:top" ! style="text-align:left" , Apparent magnitude (I) , , - style="vertical-align:top" ! style="text-align:left" , Apparent magnitude (J) , , - style="vertical-align:top" ! style="text-align:left" , Apparent magnitude (H) , , - style="vertical-align:top" ! style="text-align:left" , Apparent magnitude (K) , , - style="vertical-align:top" ! style="text-align:left" , V−R , 2.332 , - style="vertical-align:top" ! style="text-align:left" , R−I , 2.442 , - style="vertical-align:top" ! style="text-align:left" , J−H , 0.63 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAPPIST-1e
TRAPPIST-1e is a Terrestrial planet, rocky, close-to-Earth-sized exoplanet orbiting within the habitable zone around the ultracool dwarf star TRAPPIST-1, located away from Earth in the constellation of Aquarius (constellation), Aquarius. Astronomers used the transit method to find the exoplanet, a method that measures the dimming of a star when a planet crosses in front of it. The exoplanet was one of seven discovered orbiting the star using observations from the Spitzer Space Telescope. Three of the seven (''e'', ''f'', and ''g'') are in the habitable zone/"goldilocks" zone. TRAPPIST-1e is similar to Earth's mass, radius, density, gravity, temperature, and stellar flux. It is also confirmed that TRAPPIST-1e lacks a cloud-free hydrogen-dominated atmosphere, meaning it is more likely to have a compact atmosphere like the terrestrial planets in the Solar System. In November 2018, researchers determined that of the seven exoplanets in the multi-planetary system, TRAPPIST-1e has th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAPPIST-1b
TRAPPIST-1b is a terrestrial, Earth-sized exoplanet orbiting around the ultra-cool dwarf star TRAPPIST-1, located away from Earth in the constellation of Aquarius. The planet was detected using the transit method, where a planet dims the host star's light as it passes in front of it. It was first announced on May 2, 2016, and later studies were able to refine its physical parameters. The planet is about 37% more massive than Earth and about 39% larger in volume; thus its density is very similar. It is the innermost of seven planets orbiting TRAPPIST-1, all of which are terrestrial, but is too close to its star to be in the habitable zone. Observations by the James Webb Space Telescope announced between 2023 and 2024 suggest that it is either airless or has a hazy -rich atmosphere. Its albedo is very low, making it dark in color. Physical characteristics Mass, radius, and temperature TRAPPIST-1b is very similar in both mass, radius, and gravity to Earth. It has a radius of , a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAPPIST-1d
TRAPPIST-1d is a small exoplanet (about 40 percent the mass of the Earth), which orbits on the inner edge of the habitable zone of the ultracool dwarf star TRAPPIST-1, located away from Earth in the constellation of Aquarius. The exoplanet was found by using the transit method. The first signs of the planet were announced in 2016, but it was not until the following years that more information concerning the probable nature of the planet was obtained. TRAPPIST-1d is the second-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 layers. A 2018 study by the |
TRAPPIST-1g
TRAPPIST-1g 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 its distant location relative to its host star (0.047 AU) and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAPPIST-1f
TRAPPIST-1f 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 suggested a large amount of volatiles, with a 2017 stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Dwarf Star
A red dwarf is the smallest kind of star on the main sequence. Red dwarfs are by far the most common type of fusing star in the Milky Way, at least in the neighborhood of the Sun. However, due to their low luminosity, individual red dwarfs are not easily observed. Not one star that fits the stricter definitions of a red dwarf is visible to the naked eye. Proxima Centauri, the star nearest to the Sun, is a red dwarf, as are fifty of the sixty nearest stars. According to some estimates, red dwarfs make up three-quarters of the fusing stars in the Milky Way. The coolest red dwarfs near the Sun have a surface temperature of about and the smallest have radii about 9% that of the Sun, with masses about 7.5% that of the Sun. These red dwarfs have spectral types of L0 to L2. There is some overlap with the properties of brown dwarfs, since the most massive brown dwarfs at lower metallicity can be as hot as and have late M spectral types. Definitions and usage of the term "red dwar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra-cool Dwarf
An ultra-cool dwarf is a stellar or sub-stellar object that has an effective temperature lower than . This category of dwarf stars was introduced in 1997 by J. Davy Kirkpatrick, Todd J. Henry, and Michael J. Irwin. It originally included very low mass M-dwarf stars with spectral types of M7 but was later expanded to encompass stars ranging from the coldest known to brown dwarfs as cool as spectral type T6.5. Altogether, ultra-cool dwarfs represent about 15% of the astronomical objects in the stellar neighborhood of the Sun. One of the best known examples is TRAPPIST-1. Models of the formation of planets suggest that due to their low masses and the small size of their proto-planetary disks, these stars could host a relatively abundant population of terrestrial planets ranging from Mercury-sized to Earth-sized bodies, rather than a population of super-Earths and Jupiter-massed planets. The discovery of the TRAPPIST-1 planetary system, consisting of seven Earth-sized planets, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in theinaming guidelines document. The name is commonly rendered in lower case ('solar system'), as, for example, in the ''Oxford English Dictionary'' an''Merriam-Webster's 11th Collegiate Dictionary''. is the gravitationally bound Planetary system, system of the Sun and the objects that orbit it. It Formation and evolution of the Solar System, formed about 4.6 billion years ago when a dense region of a molecular cloud collapsed, forming the Sun and a protoplanetary disc. The Sun is a typical star that maintains a hydrostatic equilibrium, balanced equilibrium by the thermonuclear fusion, fusion of hydrogen into helium at its stellar core, core, releasing this energy from its outer photosphere. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tidally Locked
Tidal locking between a pair of co-orbiting astronomical bodies occurs when one of the objects reaches a state where there is no longer any net change in its rotation rate over the course of a complete orbit. In the case where a tidally locked body possesses synchronous rotation, the object takes just as long to rotate around its own axis as it does to revolve around its partner. For example, the same side of the Moon always faces Earth, although there is some variability because the Moon's orbit is not perfectly circular. Usually, only the satellite is tidally locked to the larger body. However, if both the difference in mass between the two bodies and the distance between them are relatively small, each may be tidally locked to the other; this is the case for Pluto and Charon, and for Eris and Dysnomia. Alternative names for the tidal locking process are gravitational locking, captured rotation, and spin–orbit locking. The effect arises between two bodies when their gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquarius (constellation)
Aquarius is an celestial equator, equatorial constellation of the zodiac, between Capricornus and Pisces (constellation), Pisces. Its name is Latin for "water-carrier" or "cup-carrier", and its old astronomical symbol is (♒︎), a representation of water. Aquarius is one of the oldest of the recognized constellations along the zodiac (the Sun's apparent path). It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the IAU designated constellations, 88 modern constellations. It is found in a region often called the Sea (astronomy), Sea due to its profusion of constellations with watery associations such as Cetus the whale, Pisces the fish, and Eridanus (constellation), Eridanus the river. At apparent magnitude 2.9, Beta Aquarii is the brightest star in the constellation. History and mythology Aquarius is identified as "The Great One" in the Babylonian star catalogues and represents the god Ea (god), Ea himself, who is commonl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Silla Observatory
La Silla Observatory is an astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several other telescopes are also located at the site and are partly maintained by ESO. The observatory is one of the largest in the Southern Hemisphere and was the first in Chile to be used by ESO. The La Silla telescopes and instruments are located 150 km northeast of La Serena, on the outskirts of the Atacama Desert, one of the driest and most remote areas in the world. Like other observatories in this region, La Silla is far from sources of light pollution and, like the Paranal Observatory—home to the Very Large Telescope—it has some of the darkest night skies on Earth. History Following the decision in 1963 to approve Chile as the site for the ESO observatory, scouting parties were sent to various locations to assess their suitability. The site that was decided upon was La Silla in the southern part of the Atacama Des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Period
The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars. It may also refer to the time it takes a satellite orbiting a planet or moon to complete one orbit. For celestial objects in general, the orbital period is determined by a 360° revolution of one body around its primary, ''e.g.'' Earth around the Sun. Periods in astronomy are expressed in units of time, usually hours, days, or years. Its reciprocal is the orbital frequency, a kind of revolution frequency, in units of hertz. Small body orbiting a central body According to Kepler's Third Law, the orbital period ''T'' of two point masses orbiting each other in a circular or elliptic orbit is: :T = 2\pi\sqrt where: * ''a'' is the orbit's semi-major axis * ''G'' is the gravitationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
