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GD 165
GD 165 is a system of a white dwarf and a brown dwarf of spectral types DA4 + L4, located in constellation Boötes at approximately 103 light-years from Earth. GD 165 B remained the only brown dwarf companion of a white dwarf until the discovery of GD 1400 B, which was discovered 17 years later. Nomenclature and observation "GD" means " Giclas Dwarf". The component GD 165 B was discovered in 1988 by Becklin and Zuckerman. It is the first L-type brown dwarf, and in general, the first dwarf cooler than M dwarfs discovered, but it was not recognized as a brown dwarf until the 1990s, when other such objects were found, starting from Gliese 229 B in 1995. Initially it was tentatively assigned spectral type ≥M10, but in 1999 Kirkpatrick ''et al.'' established new spectral types L and T for newly discovered objects cooler than M-type stars, and GD 165 B was reclassified L4. Distance As of 1999 the most precise distance estimate of GD 165 was the trigonometric paral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GD 165
GD 165 is a system of a white dwarf and a brown dwarf of spectral types DA4 + L4, located in constellation Boötes at approximately 103 light-years from Earth. GD 165 B remained the only brown dwarf companion of a white dwarf until the discovery of GD 1400 B, which was discovered 17 years later. Nomenclature and observation "GD" means " Giclas Dwarf". The component GD 165 B was discovered in 1988 by Becklin and Zuckerman. It is the first L-type brown dwarf, and in general, the first dwarf cooler than M dwarfs discovered, but it was not recognized as a brown dwarf until the 1990s, when other such objects were found, starting from Gliese 229 B in 1995. Initially it was tentatively assigned spectral type ≥M10, but in 1999 Kirkpatrick ''et al.'' established new spectral types L and T for newly discovered objects cooler than M-type stars, and GD 165 B was reclassified L4. Distance As of 1999 the most precise distance estimate of GD 165 was the trigonometric paral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIMBAD
SIMBAD (the Set of Identifications, Measurements and Bibliography for Astronomical Data) is an astronomical database of objects beyond the Solar System. It is maintained by the Centre de données astronomiques de Strasbourg (CDS), France. SIMBAD was created by merging the Catalog of Stellar Identifications (CSI) and the Bibliographic Star Index as they existed at the Meudon Computer Centre until 1979, and then expanded by additional source data from other catalogues and the academic literature. The first on-line interactive version, known as Version 2, was made available in 1981. Version 3, developed in the C language and running on UNIX stations at the Volgograd Observatory, was released in 1990. Fall of 2006 saw the release of Version 4 of the database, now stored in PostgreSQL, and the supporting software, now written entirely in Java. JP11 is a star catalogue containing about 4,000 objects. Currently it exists only as a part of the SIMBAD database. , SIMBAD contains informa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelu-1
Kelu-1 is a system of two brown dwarfs of spectral types L2 and L4 located in constellation Hydra at approximately 60.6 light-years from Earth. It is among the first free-floating later-than-M-type brown dwarfs discovered, and sometimes considered as prototype of L-type brown dwarfs. History of observations Discovery In 1987 María Teresa Ruiz decided to start The Calán-ESO proper-motion survey using red plates taken (starting from the 1970s) with the 1-m ESO Schmidt Camera at La Silla Observatory, Chile. The survey was not specially designed for search for brown dwarfs, but in the main for search for another type of celestial bodies—white dwarfs. Pairs of plates, separated by long span of time, were compared with blink comparator to detect objects with high proper motion. Objects with high proper motion, which were found, were selected for follow-up spectroscopy using the 3.6-m telescope, equipped with EFOSC1, at the same observatory. In March 1997 was carri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DENIS-P J1228
The Deep Near Infrared Survey of the Southern Sky (DENIS) was a deep astronomical survey of the southern sky in the near-infrared and optical wavelengths, using an ESO 1-meter telescope at the La Silla Observatory. It operated from 1996 to 2001. See also * DENIS-P J1058.7-1548 * DENIS-P J1228.2-1547 * DENIS-P J020529.0-115925 * DENIS-P J082303.1-491201 b * DENIS-P J101807.5-285931 * DENIS J024011.0-014628,6dFGS gJ024011.1-014628 * Edinburgh-Cape Blue Object Survey The Edinburgh-Cape Blue Object Survey (or EC in astronomical notation)C. Aerts, J. Christensen-Dalsgaard, D. W. Kurtz, ''Asteroseismology'' (2010), p. 105. is a major astronomical survey to discover blue stellar objects brighter than B~18 in the so ... References External links DENIS—Deep Near Infrared Survey of the Southern SkyESO 1-metre telescope Astronomical catalogues Astronomical surveys {{astronomical-catalogue-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DENIS-P J1058
The Deep Near Infrared Survey of the Southern Sky (DENIS) was a deep astronomical survey of the southern sky in the near-infrared and optical wavelengths, using an ESO 1-meter telescope at the La Silla Observatory. It operated from 1996 to 2001. See also * DENIS-P J1058.7-1548 * DENIS-P J1228.2-1547 * DENIS-P J020529.0-115925 * DENIS-P J082303.1-491201 b * DENIS-P J101807.5-285931 * DENIS J024011.0-014628,6dFGS gJ024011.1-014628 * Edinburgh-Cape Blue Object Survey The Edinburgh-Cape Blue Object Survey (or EC in astronomical notation)C. Aerts, J. Christensen-Dalsgaard, D. W. Kurtz, ''Asteroseismology'' (2010), p. 105. is a major astronomical survey to discover blue stellar objects brighter than B~18 in the so ... References External links DENIS—Deep Near Infrared Survey of the Southern SkyESO 1-metre telescope Astronomical catalogues Astronomical surveys {{astronomical-catalogue-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DENIS-P J020529
The Deep Near Infrared Survey of the Southern Sky (DENIS) was a deep astronomical survey of the southern sky in the near-infrared and optical wavelengths, using an ESO 1-meter telescope at the La Silla Observatory. It operated from 1996 to 2001. See also * DENIS-P J1058.7-1548 * DENIS-P J1228.2-1547 * DENIS-P J020529.0-115925 * DENIS-P J082303.1-491201 b * DENIS-P J101807.5-285931 * DENIS J024011.0-014628,6dFGS gJ024011.1-014628 * Edinburgh-Cape Blue Object Survey The Edinburgh-Cape Blue Object Survey (or EC in astronomical notation)C. Aerts, J. Christensen-Dalsgaard, D. W. Kurtz, ''Asteroseismology'' (2010), p. 105. is a major astronomical survey to discover blue stellar objects brighter than B~18 in the so ... References External links DENIS—Deep Near Infrared Survey of the Southern SkyESO 1-metre telescope Astronomical catalogues Astronomical surveys {{astronomical-catalogue-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2MASP J0345432+254023
This is a list of brown dwarfs. These are objects that have masses between heavy gas giants and low-mass stars. The first isolated brown dwarf discovered was Teide 1 in 1995. The first brown dwarf discovered orbiting a star was Gliese 229 B, also discovered in 1995. The first brown dwarf found to have a planet was 2M1207, discovered in 2004. , more than 2,800 brown dwarfs have been identified. An isolated object with less than about 13 Jupiter masses is technically a sub-brown dwarf or rogue planet. Because the mass of a brown dwarf is between that of a planet and that of a star, they have also been called planetars or hyperjovians. Various catalog designations have been used to name brown dwarfs. Brown dwarfs with names ending in a letter such as B, C, or D are in orbit around a primary star; those with names ending in a lower-case letter such as b, c, or d, may be exoplanets (see Exoplanet naming convention). Some exoplanets, especially those detected by radial veloci ... [...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] |
Lithium
Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and flammable, and must be stored in vacuum, inert atmosphere, or inert liquid such as purified kerosene or mineral oil. When cut, it exhibits a metallic luster, but moist air corrodes it quickly to a dull silvery gray, then black tarnish. It never occurs freely in nature, but only in (usually ionic) compounds, such as pegmatitic minerals, which were once the main source of lithium. Due to its solubility as an ion, it is present in ocean water and is commonly obtained from brines. Lithium metal is isolated electrolytically from a mixture of lithium chloride and potassium chloride. The nucleus of the lithium atom verges on instability, since the two stable lithium isotopes foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosphere
The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it being a spherical surface that is perceived to emit light. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately , or equivalently, a depth from which 50% of light will escape without being scattered. A photosphere is the deepest region of a luminous object, usually a star, that is transparent to photons of certain wavelengths. Temperature The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. Stars, except neutron stars, have no solid or liquid surface. Therefore, the photosphere is typically used to describe the Sun's or another star's visual surface. Composition of the Sun The Sun is composed primarily of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perovskite
Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as (XIIA2+VIB4+X2−3), known as the perovskite structure. Many different cations can be embedded in this structure, allowing the development of diverse engineered materials. History The mineral was discovered in the Ural Mountains of Russia by Gustav Rose in 1839 and is named after Russian mineralogist Lev Perovski (1792–1856). Perovskite's notable crystal structure was first described by Victor Goldschmidt in 1926 in his work on tolerance factors. The crystal structure was later published in 1945 from X-ray diffraction data on barium titanate by Helen Dick Megaw. Occurrence Found in the Earth's mantle, perovskite's occurrence at Khibina Massif is restricted to the silica under-saturated ultramafic rocks and foidolites, due to the instability in a paragenesis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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