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Kepler-406b
Kepler-4 is a sunlike star located about 1610 light-years away in the constellation Draco. It is in the field of view of the Kepler Mission, a NASA operation purposed with finding Earth-like planets. Kepler-4b, a Neptune-sized planet that orbits extremely close to its star, was discovered in its orbit and made public by the Kepler team on January 4, 2010. Kepler-4b was the first discovery by the Kepler satellite, and its confirmation helped to demonstrate the spacecraft's effectiveness. Nomenclature and history Kepler-4 is named for the Kepler spacecraft, a NASA telescope tasked with finding Earth-like planets that transit their stars as seen from Earth. As the previous three planets that Kepler confirmed had already been confirmed by others, Kepler-4 and its planet were the first to be discovered by the Kepler team. The star and its system were announced in Washington, D.C. at the 215th meeting of the American Astronomical Society on January 4, 2010, along with Kepler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrestrial Planet
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 plane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Draco (constellation)
Draco is a constellation in the far northern sky. Its name is Latin for dragon. It was one of the 48 Lists of constellations, constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations today. The north pole of the ecliptic is in Draco. Draco is circumpolar star, circumpolar from northern latitudes. There it is never setting and therefore can be seen all year. Features Stars Thuban (α Draconis) was the northern pole star from 3942 BC, when it moved farther north than Theta Boötis, until 1793 BC. The Egyptian Pyramids were designed to have one side facing north, with an entrance passage geometrically aligned so that Thuban would be visible at night. Due to the effects of Axial precession (astronomy), precession, it would again be the pole star around the year AD 21000. It is a blue-white giant star of magnitude 3.7, 309 light-years from Earth. The traditional name of Alpha Draconis, Thuban, means "head of the serpent". T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McDonald Observatory
McDonald Observatory is an astronomical observatory located near unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Locke in the Davis Mountains of West Texas, with additional facilities on Mount Fowlkes, approximately to the northeast. The observatory is part of The University of Texas at Austin. It is an organized research unit of the College of Natural Sciences. The observatory produces ''StarDate'', a daily syndicated radio program consisting of short segments related to astronomy that airs on both National Public Radio and commercial radio stations — about 400 affiliates in all. History McDonald Observatory was originally endowed by the Texas banker William Johnson McDonald (1844–1926), who left about $1 million — the bulk of his fortune — to The University of Texas at Austin to endow an astronomical observatory. The provision of the will was challenged by McDonald's relatives, but after a long ... [...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] |
Solar Radius
Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3: :1\,R_ = 6.957\times 10^8 \hbox is approximately 10 times the average radius of Jupiter, about 109 times the radius of the Earth, and 1/215th of an astronomical unit, the distance of the Earth from the Sun. It varies slightly from pole to equator due to its rotation, which induces an oblateness in the order of 10 parts per million. Measurements The unmanned SOHO spacecraft was used to measure the radius of the Sun by timing transits of Mercury across the surface during 2003 and 2006. The result was a measured radius of . Haberreiter, Schmutz & Kosovichev (2008) determined the radius corresponding to the solar photosphere to be . This new value is consistent with helioseismic estimates; the same study showed that previous estimates using inflection poin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Mass
The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass of the Sun. This equates to about two nonillion (short scale), two quintillion (long scale) kilograms or 2000 quettagrams: The solar mass is about times the mass of Earth (), or times the mass of Jupiter (). History of measurement The value of the gravitational constant was first derived from measurements that were made by Henry Cavendish in 1798 with a torsion balance. The value he obtained differs by only 1% from the modern value, but was not as precise. The diurnal parallax of the Sun was accurately measured during the transits of Venus in 1761 and 1769, yielding a value of (9 arcseconds, compared to the present value of ). From the value of the diurnal parallax, one can determine the distance to the Sun from the geometry o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Classification
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grating into a spectrum exhibiting the Continuum (spectrum), rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element. The strengths of the different spectral lines vary mainly due to the temperature of the photosphere, although in some cases there are true abundance differences. The ''spectral class'' of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere's temperature. Most stars are currently classified under the Morgan–Keenan (MK) system using the letters ''O'', ''B'', ''A'', ''F'', ''G'', ''K'', and ''M'', a sequence from the hottest (''O'' type) to the coo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler First Five Exoplanet Size
Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws of planetary motion, and his books ''Astronomia nova'', ''Harmonice Mundi'', and ''Epitome Astronomiae Copernicanae''. These works also provided one of the foundations for Newton's theory of universal gravitation. Kepler was a mathematics teacher at a seminary school in Graz, where he became an associate of Prince Hans Ulrich von Eggenberg. Later he became an assistant to the astronomer Tycho Brahe in Prague, and eventually the imperial mathematician to Emperor Rudolf II and his two successors Matthias and Ferdinand II. He also taught mathematics in Linz, and was an adviser to General Wallenstein. Additionally, he did fundamental work in the field of optics, invented an improved version of the refracting (or Keplerian) telescope, and wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canary Islands
The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocco. They are the southernmost of the autonomous communities of Spain. The islands have a population of 2.2 million people and they are the most populous special territory of the European Union. The seven main islands are (from largest to smallest in area) Tenerife, Fuerteventura, Gran Canaria, Lanzarote, La Palma, La Gomera, and El Hierro. The archipelago includes many smaller islands and islets, including La Graciosa, Alegranza, Isla de Lobos, Montaña Clara, Roque del Oeste, and Roque del Este. It also includes a number of rocks, including those of Salmor, Fasnia, Bonanza, Garachico, and Anaga. In ancient times, the island chain was often referred to as "the Fortunate Isles". The Canary Islands are the southernmost region of Spain, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Four Corners region with Utah to the north, Colorado to the northeast, and New Mexico to the east; its other neighboring states are Nevada to the northwest, California to the west and the Mexican states of Sonora and Baja California to the south and southwest. Arizona is the 48th state and last of the contiguous states to be admitted to the Union, achieving statehood on February 14, 1912. Historically part of the territory of in New Spain, it became part of independent Mexico in 1821. After being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848. The southernmost portion of the state was acquired in 1853 through the Gadsden Purchase. Southern Arizona is known for its desert cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territories of the United States by population, most populous U.S. state and the List of U.S. states and territories by area, 3rd largest by area. It is also the most populated Administrative division, subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous Statistical area (United States), urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento, California, Sacramento is the state's capital, while Los Angeles is the List of largest California cities by population, most populous city in the state and the List of United States cities by population, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises nearly the entire Hawaiian archipelago, 137 volcanic islands spanning that are physiographically and ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Kauai, Oahu, Molokai, Lānai, Kahoolawe, Maui, and Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawaii Island" to avoid confusion with the state or archipelago. The uninhabited Northwestern Hawaiian Islands make up most of the Papahānaumokuākea Marine National Monument, the United States' largest protected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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