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HIP 11915 B
HIP 11915 b is an exoplanet orbiting the solar twin star HIP 11915 about 190 light-years (57 parsecs, or nearly km) from Earth in the constellation Cetus. It is notable as the first exoplanet to be discovered with an orbit and mass similar to that of Jupiter (essentially, a "Jupiter analog"), suggesting that its system may be similar to that of the Solar System. It orbits its star at a distance of approximately 4.8 AU. The exoplanet was found by using the radial velocity method, where periodic Doppler shifts of spectral lines of the host star suggest an orbiting object. Physical characteristics Mass, radius and temperature HIP 11915 b is a jovian planet, an exoplanet with a mass and radius close to that of the planet Jupiter. It has a mass of 0.99 (315 ) and a likely radius of around 1 . Based on models, it is expected to have a temperature of around . This is nearly the same as the planet Jupiter. Host star The host star, HIP 11915, is a G-type star that is just abou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jorge Meléndez
Jorge Meléndez Ramírez (April 15, 1871 – November 22, 1953), was born to Rafael Meléndez and Mercedes Ramírez (daughter of Norberto Ramírez). Married to Tula Mazzini, he had three children: Jorge (who died in his youth), María de los Angeles, and Ricardo. He was the younger brother of president Carlos Meléndez. He served as 26th President of El Salvador The president of El Salvador ( es, Presidente de El Salvador), officially known as the President of the Republic of El Salvador ( es, Presidente de la República de El Salvador), is the head of state and head of government of El Salvador. He i ... from March 1, 1919 to March 1, 1923. Presidents of El Salvador 1871 births 1953 deaths People from San Salvador 20th-century Salvadoran politicians {{ElSalvador-politician-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Line
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules. These "fingerprints" can be compared to the previously collected ones of atoms and molecules, and are thus used to identify the atomic and molecular components of stars and planets, which would otherwise be impossible. Types of line spectra Spectral lines are the result of interaction between a quantum system (usually atoms, but sometimes molecules or atomic nuclei) and a single photon. When a photon has about the right amount of energy (which is connected to its frequency) to allow a change in the energy state of the system (in the case of an atom this is usually an electron changing orbitals), the photon is absorbed. Then the energy will be spontaneously re-emitted, either as one photon at the same frequenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Analog
An Earth analog, also called an Earth analogue, Earth twin, or second Earth, is a planet or moon with environmental conditions similar to those found on Earth. The term Earth-like planet is also used, but this term may refer to any terrestrial planet. The possibility is of particular interest to astrobiologists and astronomers under reasoning that the more similar a planet is to Earth, the more likely it is to be capable of sustaining complex extraterrestrial life. As such, it has long been speculated and the subject expressed in science, philosophy, science fiction and popular culture. Advocates of space colonization and space and survival have long sought an Earth analog for settlement. In the far future, humans might artificially produce an Earth analog by terraforming. Before the scientific search for and study of extrasolar planets, the possibility was argued through philosophy and science fiction. Philosophers have suggested that the size of the universe is such that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrestrial Planets
A terrestrial planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the Sun: Mercury, Venus, Earth and Mars. Among astronomers who use the geophysical definition of a planet, two or three planetary-mass satellites – Earth's Moon, Io, and sometimes Europa – may also be considered terrestrial planets; and so may be the rocky protoplanet-asteroids Pallas and Vesta.Emily Lakdawalla et al.What Is A Planet?The Planetary Society, 21 April 2020 The terms "terrestrial planet" and "telluric planet" are derived from Latin words for Earth (''Terra'' and ''Tellus''), as these planets are, in terms of structure, ''Earth-like''. Terrestrial planets are generally studied by geologists, astronomers, and geophysicists. Terrestrial planets have a solid planetary surface, making them substantially different from the larger gaseous planet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area and the seventh most populous. Its capital is Brasília, and its most populous city is São Paulo. The federation is composed of the union of the 26 States of Brazil, states and the Federal District (Brazil), Federal District. It is the largest country to have Portuguese language, Portuguese as an List of territorial entities where Portuguese is an official language, official language and the only one in the Americas; one of the most Multiculturalism, multicultural and ethnically diverse nations, due to over a century of mass Immigration to Brazil, immigration from around the world; and the most populous Catholic Church by country, Roman Catholic-majority country. Bounded by the Atlantic Ocean on the east, Brazil has a Coastline of Brazi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of São Paulo
The University of São Paulo ( pt, Universidade de São Paulo, USP) is a public university in the Brazilian state of São Paulo. It is the largest Brazilian public university and the country's most prestigious educational institution, the best university in Ibero-America, and holds a high reputation among world universities, being ranked 100 worldwide in reputation by the Times Higher Education World University Rankings. The USP is involved in teaching, research and university extension in all areas of knowledge, offering a broad range of courses. The university was founded in 1934, regrouping already existing schools in the state of São Paulo, such as the Faculdade de Direito do Largo de São Francisco (Faculty of Law), the Escola Politécnica (Engineering School) and the Escola Superior de Agricultura Luiz de Queiroz (College of Agriculture). The university's foundation is marked by the creation in 1934 of the Faculdade de Filosofia, Ciências e Letras (Faculty of Philoso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-type Main-sequence Star
A G-type main-sequence star (Spectral type: G-V), also often, and imprecisely called a yellow dwarf, or G star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective temperature between about 5,300 and 6,000 K. Like other main-sequence stars, a G-type main-sequence star is converting the element hydrogen to helium in its core by means of nuclear fusion, but can also fuse helium when hydrogen runs out. The Sun, the star in the center of the Solar System to which the Earth is gravitationally bound, is an example of a G-type main-sequence star (G2V type). Each second, the Sun fuses approximately 600 million tons of hydrogen into helium in a process known as the proton–proton chain (4 hydrogens form 1 helium), converting about 4 million tons of matter to energy. Besides the Sun, other well-known examples of G-type main-sequence stars include Alpha Centauri, Tau Ceti, Capella and 51 Pegasi. The term ''yel ... [...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] |
Grand Tack Hypothesis
In planetary astronomy, the grand tack hypothesis proposes that Jupiter formed at 3.5 AU, then migrated inward to 1.5 AU, before reversing course due to capturing Saturn in an orbital resonance, eventually halting near its current orbit at 5.2 AU. The reversal of Jupiter's planetary migration is likened to the path of a sailboat changing directions ( tacking) as it travels against the wind. The planetesimal disk is truncated at 1.0 AU by Jupiter's migration, limiting the material available to form Mars. Jupiter twice crosses the asteroid belt, scattering asteroids outward then inward. The resulting asteroid belt has a small mass, a wide range of inclinations and eccentricities, and a population originating from both inside and outside Jupiter's original orbit. Debris produced by collisions among planetesimals swept ahead of Jupiter may have driven an early generation of planets into the Sun. Description In the ''grand tack hypothesis'' Jupiter underwent a two-phase migration after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's light caused by interstellar dust along the line of sight to the observer. The word ''magnitude'' in astronomy, unless stated otherwise, usually refers to a celestial object's apparent magnitude. The magnitude scale dates back to the ancient Roman astronomer Claudius Ptolemy, whose star catalog listed stars from 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined in a way to closely match this historical system. The scale is reverse logarithmic: the brighter an object is, the lower its magnitude number. A difference of 1.0 in magnitude corresponds to a brightness ratio of \sqrt /math>, or about 2.512. For example, a star of magnitude 2.0 is 2.512 times as bright as a star of magnitude 3.0, 6. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universe Today
Universe Today (U.T.) is a popular North American-based non-commercial space and astronomy news website. The domain was registered on December 30, 1998, and the website went live in March 1999, founded by Canadian Fraser Cain. The ''Universe Today'' assumed its current form on July 24, 2003, featuring astronomy news and space-related issues. By early September 2005, the forum section merged with ''Bad Astronomy'' as a combined site with the BAUT forum. During April 2011, the Association of British Science Writers noted that ''Universe Today'' decided not to make preparations for reporting on embargoed stories until they are public knowledge. Emily Lakdawalla said that she relies on ''Universe Today'' and ''Bad Astronomy'' to "give ... an independent look at big news stories". Publications ''Universe Today'' has published two books, which are available both as e-books and on physical media: * * See also * ''Astronomy Cast'' * ''Space.com'' * ''The Space Show ''The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelvin
The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907). The Kelvin scale is an absolute thermodynamic temperature scale, meaning it uses absolute zero as its null (zero) point. Historically, the Kelvin scale was developed by shifting the starting point of the much-older Celsius scale down from the melting point of water to absolute zero, and its increments still closely approximate the historic definition of a degree Celsius, but since 2019 the scale has been defined by fixing the Boltzmann constant to be exactly . Hence, one kelvin is equal to a change in the thermodynamic temperature that results in a change of thermal energy by . The temperature in degree Celsius is now defined as the temperature in kelvins minus 273.15, meaning t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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