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Hyperjovian
A super-Jupiter is a gas giant exoplanet that is more massive than the planet Jupiter. For example, companions at the planet–brown dwarf borderline have been called super-Jupiters, such as around the star Kappa Andromedae. By 2011 there were 180 known super-Jupiters, some hot, some cold. Even though they are more massive than Jupiter, they remain about the same size as Jupiter up to 80 Jupiter masses. This means that their surface gravity and density go up proportionally to their mass. The increased mass compresses the planet due to gravity, thus keeping it from being larger. In comparison, planets somewhat lighter than Jupiter can be larger, so-called "puffy planets" (gas giants with a large diameter but low density). An example of this may be the exoplanet HAT-P-1b with about half the mass of Jupiter but about 1.38 times larger diameter. CoRoT-3b, with a mass around 22 Jupiter masses, is predicted to have an average density of 26.4 g/cm3, greater than osmium (22.6 g/cm3), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth the mass of the Sun. Jupiter is the List of brightest natural objects in the sky, third brightest natural object in the Earth's night sky after the Moon and Venus, and it has been observed since Pre-history, prehistoric times. It was named after the Jupiter (mythology), Roman god Jupiter, the king of the gods. Jupiter is primarily composed of hydrogen, but helium constitutes one-quarter of its mass and one-tenth of its volume. It probably has a rocky core of heavier elements, but, like the other giant planets in the Solar System, it lacks a well-defined solid surface. The ongoing contraction of Jupiter's interior generates more heat than it receives from the Sun. Because of its rapid rotation, the planet' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occurred about 370,000 ... [...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] |
Red Dwarf
''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. The series follows low-ranking technician Dave Lister, who awakens after being in suspended animation for three million years to find that he is the last living human, and that he is alone on the mining spacecraft ''Red Dwarf''—save for a hologram his deceased bunkmate Arnold Rimmer and "Cat", a life form which evolved from Lister's pregnant cat. As of 2020, the cast includes Chris Barrie as Rimmer, Craig Charles as Lister, Danny John-Jules as Cat, Robert Llewellyn as the sanitation droid Kryten, and Norman Lovett as the ship's computer, Holly. To date, twelve series of the show have aired, (including one miniseries), in addition to a feature-length special ''The Promised Land''. Four novels were published from 1989 to 1996. Two pilot ep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Planet Types
The following is a list of planet types by their mass, orbit, physical and chemical composition, or by another classification. The IAU defines that a ''planet'' in the Solar System must orbit around the Sun, has enough mass to assume hydrostatic equilibrium, and has " cleared its neighborhood". There is currently no accepted definition for exoplanets. Under the IAU definition, true or "major planets" can be distinguished from other planetary-mass objects (PMOs), such as dwarf planets and sub-brown dwarfs. Nonetheless, certain planet types have been applied to other planetary-mass objects; the Pluto–Charon system has been referred to as " double dwarf planets", for instance. By mass regime By orbital regime By composition Other types See also * * Minor planet * * Stellar classification * Substellar object * Sudarsky's gas giant classification Notes References External links Periodic Table of ExoplanetsaPlanetary Habitability Laboratory Universit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-1704b
Kepler-1704b is a super-Jupiter on a highly eccentric orbit around the star Kepler-1704. It has a mass of 4.51 . The planet's distance from its star varies from 0.16 to 3.9 AU. It is a failed hot Jupiter, been scattered from its birth orbit to orbit with periastron just above tidal circularization distance. Characteristics Kepler-1704b is much more massive than Jupiter, at 4.51 M''J.'' The high planetary mass makes Kepler-1704b a super-Jupiter. Kepler-1704b goes on a highly eccentric 2.7 year-long (988.88 days) orbit around its star as well as transiting. The extreme eccentricity yields a temperature difference of up to 700 K. Star The star, Kepler-1704, is a G2, 5745-kelvin star from Earth and the sun. It has a mass of , a radius of , and a luminosity of . The high radius for the star's mass hints that Kepler-1704 is not a main-sequence star. See also *Gas giant *List of planet types * Kepler-419b *HD 80606 b HD 80606 b (also Struve 1341 B b or HIP 45982 b) is an eccent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Giant
An ice giant is a giant planet composed mainly of elements heavier than hydrogen and helium, such as oxygen, carbon, nitrogen, and sulfur. There are two ice giants in the Solar System: Uranus and Neptune. In astrophysics and planetary science the term "ices" refers to volatile chemical compounds with freezing points above about 100 K, such as water, ammonia, or methane, with freezing points of 273 K (0°C), 195 K (−78°C), and 91 K (−182°C), respectively (see Volatiles). In the 1990s, it was determined that Uranus and Neptune are a distinct class of giant planet, separate from the other giant planets, Jupiter and Saturn, which are gas giants predominantly composed of hydrogen and helium. As such, Neptune and Uranus are now referred to as ''ice giants''. Lacking well defined solid surfaces, they are primarily composed of gases and liquids. Their constituent compounds were solids when they were primarily incorporated into the planets during their format ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extrasolar Planet
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 (astronomy), 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, List of multiplanetary systems, multiple planets have been observed around a star. About 1 in 5 Solar analog, 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 star, K-type stars. have an "Earth-sized"For the purpose of this 1 in 5 ... [...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] |
Kappa Andromedae B
} Kappa Andromedae b is a directly imaged substellar object and likely superjovian-mass planet orbiting Kappa Andromedae, a young B9IV star in the Andromeda constellation, about 170 light-years away. The companion's mass is roughly 13 times the mass of Jupiter. As early history on Kappa And b is filled with debate over whether it is an exoplanet or a brown dwarf, some scientists have broadly described it as a "super-Jupiter" object. Discovery Kappa Andromedae b was discovered through near-infrared high-contrast imaging the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS) survey at the Subaru Telescope, located atop Mauna Kea, Hawaii. Follow-up Subaru observations taken between January and July 2012 and covering a wider wavelength range confirmed that Kappa Andromedae is gravitationally bound (not a background star) and had infrared colors consistent with a substellar (possibly planet–mass) companion. Atmosphere and orbital properties The low resolution near-i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Gravity
The surface gravity, ''g'', of an astronomical object is the gravitational acceleration experienced at its surface at the equator, including the effects of rotation. The surface gravity may be thought of as the acceleration due to gravity experienced by a hypothetical test particle which is very close to the object's surface and which, in order not to disturb the system, has negligible mass. For objects where the surface is deep in the atmosphere and the radius not known, the surface gravity is given at the 1 bar pressure level in the atmosphere. Surface gravity is measured in units of acceleration, which, in the SI system, are meters per second squared. It may also be expressed as a multiple of the Earth's standard surface gravity, which is equal to :''g'' = In astrophysics, the surface gravity may be expressed as log ''g'', which is obtained by first expressing the gravity in cgs units, where the unit of acceleration and surface gravity is centimeters per seco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy And Astrophysics
''Astronomy & Astrophysics'' is a monthly peer-reviewed scientific journal covering theoretical, observational, and instrumental astronomy and astrophysics. The journal is run by a Board of Directors representing 27 sponsoring countries plus a representative of the European Southern Observatory. The journal is published by EDP Sciences and the editor-in-chief is . History Origins ''Astronomy and Astrophysics'' (A&A) was created as an answer to the publishing scenario found in Europe in the 1960s. At that time, multiple journals were being published in several countries around the continent. These journals usually had a limited number of subscribers, and published articles in languages other than English, resulting in a small number of citations compared to American and British journals. Starting in 1963, conversations between astronomers from European countries assessed the need for a common astronomical journal. On 8 April 1968, leading astronomers from Belgium, Denmark, Fran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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