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PSR B1620−26
PSR B1620−26 is a binary star system located at a distance of 3,800 parsecs (12,400 light-years) in the globular cluster of Messier 4 (M4, NGC 6121) in the constellation of Scorpius. The system is composed of a pulsar (PSR B1620−26 A) and a white dwarf star (WD B1620−26, or PSR B1620−26 B). As of 2000, the system is also confirmed to have an exoplanet orbiting the two stars. History The double system (''triple'' including the substellar companion) is just outside the core of the globular cluster. The age of the cluster has been estimated to be about 12.2 billion years. Hence this is the age estimate for the birth of the planet, and two stars. There is a minor dispute about the proper nomenclature rules to use for this unusual star system. One side regards the A/B convention of naming binary stars as having priority, so that the pulsar is PSR B1620−26 A, the white dwarf companion is PSR B1620−26 B and the planet is PSR B1620−26 c. The other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Location Of Pulsar B1620-26
In geography, location or place are used to denote a region (point, line, or area) on Earth's surface or elsewhere. The term ''location'' generally implies a higher degree of certainty than ''place'', the latter often indicating an entity with an ambiguous boundary, relying more on human or social attributes of place identity and sense of place than on geometry. Types Locality A locality, settlement, or populated place is likely to have a well-defined name but a boundary that is not well defined varies by context. London, for instance, has a legal boundary, but this is unlikely to completely match with general usage. An area within a town, such as Covent Garden in London, also almost always has some ambiguity as to its extent. In geography, location is considered to be more precise than "place". Relative location A relative location, or situation, is described as a displacement from another site. An example is "3 miles northwest of Seattle". Absolute location An absolute locati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSR B1620−26 C
PSR may refer to: Organizations * Pacific School of Religion, Berkeley, California, US * Palestinian Center for Policy and Survey Research * Physicians for Social Responsibility, US ;Political parties: * Revolutionary Socialist Party (Portugal) (''Partido Socialista Revolucionário'') * Romanian Socialist Party (present-day) Places * Abruzzo Airport (IATA airport code), near Pescara, Italy * Pasir Ris MRT station (MRT station abbreviation), Singapore * Pioneer Scout Reservation, a Boy Scout camp in Ohio, US Science and technology * Pulsar, a kind of star * Primary radar * Perimeter surveillance radar * Posthumous sperm retrieval from dead men Computing * PHP Standard Recommendation * Predictive state representation of a system * Problem Steps Recorder, psr.exe, a Microsoft utility * Panel Self-Refresh in Embedded DisplayPort Law enforcement and military * US Precision Sniper Rifle *PSR-90, a Pakistani Precision Sniper Rifle Other uses * Portuguese Sign Language (ISO 639-3 l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scorpius (constellation)
Scorpius is a zodiac constellation located in the Southern celestial hemisphere, where it sits near the center of the Milky Way, between Libra to the west and Sagittarius to the east. Scorpius is an ancient constellation that pre-dates the Greeks; it is one of the 48 constellations identified by the Greek astronomer Ptolemy in the second century. Its old astronomical symbol is (♏︎). Notable features Stars Scorpius contains many bright stars, including Antares (α Sco), "rival of Mars," so named because of its distinct reddish hue; β1 Sco (Graffias or Acrab), a triple star; δ Sco ( Dschubba, "the forehead"); θ Sco ( Sargas, of unknown origin); ν Sco (Jabbah); ξ Sco; π Sco (Fang); σ Sco (Alniyat); and τ Sco (Paikauhale). Marking the tip of the scorpion's curved tail are λ Sco ( Shaula) and υ Sco (Lesath), whose names both mean "sting." Given their proximity to one another, λ Sco and υ Sco are sometimes referred to as the Cat's Eyes. The constellat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Dwarfs
A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes from the emission of residual thermal energy; no fusion takes place in a white dwarf. The nearest known white dwarf is at 8.6 light years, the smaller component of the Sirius binary star. There are currently thought to be eight white dwarfs among the hundred star systems nearest the Sun. The unusual faintness of white dwarfs was first recognized in 1910. The name ''white dwarf'' was coined by Willem Luyten in 1922. White dwarfs are thought to be the final evolutionary state of stars whose mass is not high enough to become a neutron star or black hole. This includes over 97% of the other stars in the Milky Way. After the hydrogen- fusing period of a main-sequence star of low or medium mass ends, such a star will expand to a red gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulsars
A pulsar (from ''pulsating radio source'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Earth (similar to the way a lighthouse can be seen only when the light is pointed in the direction of an observer), and is responsible for the pulsed appearance of emission. Neutron stars are very dense and have short, regular rotational periods. This produces a very precise interval between pulses that ranges from milliseconds to seconds for an individual pulsar. Pulsars are one of the candidates for the source of ultra-high-energy cosmic rays. (See also centrifugal mechanism of acceleration.) The periods of pulsars make them very useful tools for astronomers. Observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. The first extrasolar planets were discovered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Stars
A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in which case they are called ''visual binaries''. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known. They may also be detected by indirect techniques, such as spectroscopy (''spectroscopic binaries'') or astrometry (''astrometric binaries''). If a binary star happens to orbit in a plane along our line of sight, its components will eclipse and transit each other; these pairs are called ''eclipsing binaries'', or, together with other binaries that change brightness as they orbit, ''photometric binaries''. If components in binary star systems are close enough they can gravitationally distort their mutual outer stellar atmospheres. In some cases, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulsar Planet
Pulsar planets are planets that are found orbiting pulsars, or rapidly rotating neutron stars. The first such planets to be discovered were around a millisecond pulsar and were the first extrasolar planets to be confirmed as discovered. History Pulsar planets are discovered through pulsar timing measurements, to detect anomalies in the pulsation period. Any bodies orbiting the pulsar will cause regular changes in its pulsation. Since pulsars normally rotate at near-constant speed, any changes can easily be detected with the help of precise timing measurements. The discovery of pulsar planets was unexpected; pulsars or neutron stars have previously gone supernova, and it was thought that any planets orbiting such stars would have been destroyed in the explosion. In 1991, Andrew G. Lyne announced the first-ever pulsar planet discovered around PSR 1829–10. However, this was later retracted, just before the first real pulsar planets were announced. In 1992, Aleksander Wolszczan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Trianguli
Delta Trianguli, Latinized from Delta Tri, is a spectroscopic binary star system approximately away in the constellation of Triangulum. The primary star is a yellow dwarf, while the secondary star is thought to be an orange dwarf. It has an apparent magnitude of +4.87 and forms an optical (line-of-sight) triple with Gamma Trianguli and 7 Trianguli. Stellar components Delta Trianguli A is a main sequence star with a stellar classification of G0V and a mass similar to the Sun. The spectral characteristics of the smaller companion Delta Trianguli B are not well determined since the close orbit makes observations difficult, with estimates of the spectral class ranging from G9V to K4V. The Delta Trianguli stars orbit their center of mass with an estimated separation of 0.106 AU; it is certainly less than one AU. The orbital period is 10.02 days and the eccentricity of the orbit is only 0.020. The orbit is inclined about 167° to the line of sight from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSR B1257+12
PSR B1257+12, previously designated PSR 1257+12, alternatively designated PSR J1300+1240, is a millisecond pulsar located 2,300 light-years from the Sun in the constellation of Virgo, rotating at about 161 times per second (faster than a blender's blade). It is also named Lich, after a powerful, fictional undead creature of the same name. The pulsar has a planetary system with three known planets, named "Draugr" (PSR B1257+12 b or PSR B1257+12 A), "Poltergeist" (PSR B1257+12 c, or PSR B1257+12 B) and "Phobetor" (PSR B1257+12 d, or PSR B1257+12 C), respectively. They were both the first extrasolar planets and the first pulsar planets to be discovered; B and C in 1992 and A in 1994. A is the lowest-mass planet yet discovered by any observational technique, with somewhat less than twice the mass of Earth's moon. Nomenclature The convention that arose for designating pulsars was that of using the letters PSR (Pulsating Source of Radio) followed by the pulsar's right ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stephen Thorsett
Stephen Erik Thorsett (born December 3, 1964) is an American academic and astronomer serving as the president of Willamette University. His research interests include radio pulsars and gamma ray bursts. He is known for measurements of the masses of neutron stars and for the use of binary pulsars to test the theory of general relativity. Thorsett was a professor and dean at the University of California, Santa Cruz, before becoming president of Willamette University in July 2011. Early life and education Thorsett and his twin brother, David Thorsett, were born in New Haven, Connecticut, to Grant Thorsett and his wife, Karen. Stephen grew up in Salem, Oregon, where his father was a biology professor at Willamette University. After attending elementary school and junior high in Salem, he graduated from South Salem High School in 1983. During his youth, he earned money picking berries and with several jobs at Willamette. Following high school, he attended Carleton College in Northfiel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSR B1620−26 B
PSR B1620−26 b is an exoplanet located approximately 12,400 light-years from Earth in the constellation of Scorpius. It bears the unofficial nicknames "Methuselah" and "the Genesis planet" (named after the Biblical character Methuselah, who, according to the Bible, lived to be the oldest person) due to its extreme age. The planet is in a circumbinary orbit around the two stars of PSR B1620−26 (which are a pulsar (PSR B1620−26 A) and a white dwarf ( WD B1620-26)) and is the first circumbinary planet ever confirmed. It is also the first planet found in a globular cluster. The planet is one of the oldest known extrasolar planets, believed to be about 12.7 billion years old. Characteristics Mass, orbit, and age PSR B1620−26 b has a mass of 2.627 times that of Jupiter, and orbits at a distance of 23 AU (3.4 billion km), a little larger than the distance between Uranus and the Sun. Each orbit of the planet takes about 100 years. The triple system is just outside the core ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Evolution Of The PSR B1620-26 System
''The'' () is a grammatical article in English, denoting persons or things already mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with pronouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of pronoun ''thee'') when followed by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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