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Circumbinary
A circumbinary planet is a planet that orbits two stars instead of one. The two stars orbit each other in a binary system, while the planet typically orbits farther from the center of the system than either of the two stars. In contrast, circumstellar planets in a binary system have stable orbits around one of the two stars, closer in than the orbital distance of the other star. Studies in 2013 showed that there is a strong hint that a circumbinary planet and its stars originate from a single disk. Observations and discoveries Confirmed planets PSR B1620-26 The first confirmed circumbinary planet was found orbiting the system PSR B1620-26, which contains a millisecond pulsar and a white dwarf and is located in the globular cluster M4. The existence of the third body was first reported in 1993, and was suggested to be a planet based on 5 years of observational data. In 2003 the planet was characterised as being 2.5 times the mass of Jupiter in a low eccentricity orbit wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumbinary Planetary Systems
A circumbinary planet is a planet that orbits two stars instead of one. The two stars orbit each other in a binary system, while the planet typically orbits farther from the center of the system than either of the two stars. In contrast, circumstellar planets in a binary system have stable orbits around one of the two stars, closer in than the orbital distance of the other star. Studies in 2013 showed that there is a strong hint that a circumbinary planet and its stars originate from a single disk. Observations and discoveries Confirmed planets PSR B1620-26 The first confirmed circumbinary planet was found orbiting the system PSR B1620-26, which contains a millisecond pulsar and a white dwarf and is located in the globular cluster M4. The existence of the third body was first reported in 1993, and was suggested to be a planet based on 5 years of observational data. In 2003 the planet was characterised as being 2.5 times the mass of Jupiter in a low eccentricity orbit wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PH1b
PH1b (standing for "Planet Hunters 1"), or by its NASA designation Kepler-64b, is an extrasolar planet found in a circumbinary orbit in the quadruple star system Kepler-64. The planet was discovered by two amateur astronomers from the Planet Hunters project of amateur astronomers using data from the Kepler space telescope with assistance of a Yale University team of international astronomers. The discovery was announced on 15 October 2012. It is the first known transiting planet in a quadruple star system, first known circumbinary planet in a quadruple star system, and the first planet in a quadruple star system found. It was the first confirmed planet discovered by PlanetHunters.org. An independent and nearly simultaneous detection was also reported from a revision of Kepler space telescope data using a transit detection algorithm. Star system The giant planet is Neptune-sized, about 20-55 Earth-masses (). It has a radius 6.2 times that of Earth. The star system is 7200 ligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-1647b
Kepler-1647b (sometimes named Kepler-1647(AB)-b to distinguish it from the secondary component) is a circumbinary exoplanet that orbits the binary star system Kepler-1647, from Earth in the constellation Cygnus. It was announced on June 13, 2016, in San Diego at a meeting of the American Astronomical Society. It was detected using the transit method, when it caused the dimming of the primary star, and then again of the secondary star blended with the primary star eclipse. The first transit of the planet was identified in 2012, but at the time the single event was not enough to rule out contamination, or confirm it as a planet. It was discovered by the analysis of the Kepler light-curve, which showed the planet in transit. Characteristics Mass and orbit The exoplanet is a gas giant, similar in size to Jupiter, and has an orbital period of 1107 days. This is the longest transit period of any confirmed transiting Kepler exoplanet discovered yet. It is also the largest circumb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planet Hunters
Planet Hunters is a citizen science project to find exoplanets using human eyes. It does this by having users analyze data from the NASA Kepler space telescope and the NASA Transiting Exoplanet Survey Satellite. It was launched by a team led by Debra Fischer at Yale University, as part of the Zooniverse project. History Planet Hunters and Planet Hunters 2.0 The project was launched on December 16, 2010, after the first Data Release of Kepler data as the Planet Hunters Project. 300,000 volunteers participated in the project and the project team published 8 scientific papers. On December 14, 2014, the project was re-launched as Planet Hunters 2.0, with an improved website and considering that the volunteers will look at K2 data. As of November 2018 Planet Hunters identified 50% of the known planets with an orbital period larger than two years. Non-Planet Hunters project: Exoplanet Explorers In 2017 the project Exoplanet Explorers was launched. It was another planet hunting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-16b
Kepler-16b (formally Kepler-16 (AB)-b) is an extrasolar planet. It is a Saturn-mass planet consisting of half gas and half rock and ice, and it orbits a binary star, Kepler-16, with a period of 229 days. "[It] is the first confirmed, unambiguous example of a circumbinary planet – a planet orbiting not one, but two stars," said Josh Carter of the Harvard-Smithsonian Center for Astrophysics, Center for Astrophysics Harvard & Smithsonian, one of the discovery team. Kepler-16b was Discovery (observation), discovered using the space observatory aboard NASA's Kepler (spacecraft), Kepler spacecraft. Scientists were able to detect Kepler-16b using the transit method, when they noticed the dimming of one of the system's stars even when the other was not eclipsing it. Furthermore, duration of transits and timing all the eclipses and transits of Kepler-16b and its stars in the system has allowed for unusually high Accuracy and precision, precision in the calculations of the sizes and masse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler Space Telescope
The Kepler space telescope is a disused space telescope launched by NASA in 2009 to discover Earth-sized planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched into an Earth-trailing heliocentric orbit. The principal investigator was William J. Borucki. After nine and a half years of operation, the telescope's reaction control system fuel was depleted, and NASA announced its retirement on October 30, 2018. Designed to survey a portion of Earth's region of the Milky Way to discover Earth-size exoplanets in or near habitable zones and estimate how many of the billions of stars in the Milky Way have such planets, Kepler's sole scientific instrument is a photometer that continually monitored the brightness of approximately 150,000 main sequence stars in a fixed field of view. These data were transmitted to Earth, then analyzed to detect periodic dimming caused by exoplanets that cross in front of their host star. Only planets whose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AK Scorpii
AK Scorpii is a Herbig Ae/Be star and spectroscopic binary star about 459 light-years distant in the constellation Scorpius. The star belongs to the nearby Upper Centaurus–Lupus star-forming region and the star is actively accreting material. The binary is surrounded by a circumbinary disk that was imaged with VLT/SPHERE in scattered light and with ALMA. Characteristics AK Scorpii is about 18 million years old, which is young on astronomical timescales. The binary consists out of two stars with an equal mass of 1.25 respectively and the two stars orbit each other within 13.6 days. The binary is surrounded by a narrow ring of dust with a radius of about 30 astronomical units and the gap between the binary and the dust disk is filled by some gas. The binary is in an eccentric orbit that causes variable accretion rates due to gravitational interactions with the disk. During the furthest point in the orbit of the binary (apastron), matter is dragged from the inner ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eclipsing Binary
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, these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-453b
Kepler-453b is a transiting circumbinary exoplanet in the binary-star system Kepler-453. It orbits the binary system in the habitable zone every 240.5 days. The orbit of the planet is inclined relative to the binary orbit therefore precession of the orbit leads to it spending most of its time in a non-transiting configuration. By the time the TESS and PLATO Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ... spacecraft are available for follow up observations it will no longer be transiting. References Exoplanets discovered in 2015 Transiting exoplanets Giant planets in the habitable zone 453b Circumbinary planets {{extrasolar-planet-stub Lyra (constellation) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Star
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, thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subdwarf B Star
A B-type subdwarf (sdB) is a kind of subdwarf star with spectral type B. They differ from the typical subdwarf by being much hotter and brighter. They are situated at the "extreme horizontal branch" of the Hertzsprung–Russell diagram. Masses of these stars are around 0.5 solar masses, and they contain only about 1% hydrogen, with the rest being helium. Their radius is from 0.15 to 0.25 solar radii, and their temperature is from 20,000 to 40,000K. These stars represent a late stage in the evolution of some stars, caused when a red giant star loses its outer hydrogen layers before the core begins to fuse helium. The reasons why this premature mass loss occurs are unclear, but the interaction of stars in a binary star system is thought to be one of the main mechanisms. Single subdwarfs may be the result of a merger of two white dwarfs. The sdB stars are expected to become white dwarfs without going through any more giant stages. Subdwarf B stars, being more luminous than white ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 202206
HD 202206 is a binary star system in the southern constellation of Capricornus. With an apparent visual magnitude of +8.1, it is too faint to be visible to the naked eye. It is located at a distance of 150 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +14.7 km/s. The primary component is a G-type main-sequence star with a stellar classification of G6V, indicating it is generating energy through core hydrogen fusion. It is an estimated three billion years old and is spinning with a projected rotational velocity of 2.3 km/s. It is a metal-rich star – what astronomers term the abundance of elements of higher atomic number than helium – which may explain the star's unusually high luminosity for its class. The star has a slightly greater mass and radius compared to the Sun. __NOTOC__ Companions In 2000, analysis of radial velocity measurements of the star revealed the existence of a brown dwarf com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
