|
Gliese 581b
Gliese 581b or Gl 581b is an exoplanet orbiting within the Gliese 581 system, located away from Earth in the Libra constellation. It is the first planet discovered of three confirmed in the system so far, and the second in order from the star. Discovery The planet was discovered by a team of French and Swiss astronomers, who announced their findings on November 30, 2005, as a discovery of one of the smallest exoplanets then found, with one conclusion being that planets may be more common around the smallest stars. It was the fifth planet found around a red dwarf star (after Gliese 876's first three planets and Gliese 436 b). The planet was discovered using the HARPS instrument, with which they found the host star to have a wobble that implied the existence of the planet. The astronomers published their results in '' Astronomy and Astrophysics Letters''. Orbit and mass Gliese 581b has a minimum mass of approximately 15.8 times the Earth's mass, similar to Neptune's mass. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planet's equator. For pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanets Detected By Radial Velocity
An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detected in 1988, was confirmed in 2003. In 2016, it was recognized that the first possible evidence of an exoplanet had been noted in 1917. In collaboration with ground-based and other space-based observatories the James Webb Space Telescope (JWST) is expected to give more insight into exoplanet traits, such as their composition, environmental conditions, and potential for life. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. About 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanets Discovered In 2005
An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detected in 1988, was confirmed in 2003. In 2016, it was recognized that the first possible evidence of an exoplanet had been noted in 1917. In collaboration with ground-based and other space-based observatories the James Webb Space Telescope (JWST) is expected to give more insight into exoplanet traits, such as their composition, environmental conditions, and potential for life. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanets In The Gliese Catalog
An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first detected in 1988, was confirmed in 2003. In 2016, it was recognized that the first possible evidence of an exoplanet had been noted in 1917. In collaboration with ground-based and other space-based observatories the James Webb Space Telescope (JWST) is expected to give more insight into exoplanet traits, such as their composition, environmental conditions, and potential for life. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. About 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy & Astrophysics
''Astronomy & Astrophysics (A&A)'' is a monthly peer-reviewed scientific journal covering theoretical, observational, and instrumental astronomy and astrophysics. It is operated by an editorial team under the supervision of a board of directors representing 27 sponsoring countries plus a representative of the European Southern Observatory. The journal is published by EDP Sciences and the current editors-in-chief are Thierry Forveille and João Alves. History Origins ''Astronomy & Astrophysics'' was created as an answer to the publishing situation found in Europe in the 1960s. At that time, multiple journals were being published in several countries around the continent. These journals usually had a limited number of subscribers, and articles were written in languages other than English. They were less widely read than American and British journals and the research they reported had therefore less impact in the community. Starting in 1963, conversations between astronomers from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'' is the peer review, peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' cover the full range of List of academ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitability Of Red Dwarf Systems
The theorized habitability of red dwarf systems is determined by a large number of factors. Modern evidence suggests that planets in red dwarf systems are unlikely to be habitable, due to high probability of tidal locking, likely lack of atmospheres, and the high stellar variation many such planets would experience. However, the sheer number and longevity of red dwarfs could likely provide ample opportunity to realize any small possibility of habitability. Current arguments concerning the habitability of red dwarf systems are unresolved, and the area remains an open question of study in the fields of climate modeling and the evolution of life on Earth. Observational data and statistical arguments suggest that red dwarf systems are uninhabitable for indeterminate reasons. On the other hand, 3D climate models favor habitability and wider habitable zones for slow rotating and tidally locked planets. A major impediment to the development of life in red dwarf systems is the inten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gliese 581e
Gliese 581e or Gl 581e is an exoplanet orbiting within the Gliese 581 system, located away from Earth in the Libra constellation. It is the third planet discovered in the system (fourth if the disputed planet candidate Gliese 581d is included) and the first in order from the star. The planet was discovered by an Observatory of Geneva team led by Michel Mayor, using the HARPS instrument on the European Southern Observatory telescope in La Silla, Chile. The discovery was announced on 21 April 2009. Mayor's team employed the radial velocity technique, in which the orbit size and mass of a planet are determined based on the small perturbations it induces in its parent star's orbit via gravity. With a minimum mass of about 1.9 Earth masses, Gliese 581e was the least massive exoplanet known around a normal star at the time of discovery in 2009, with only PSR B1257+12 A being less massive. A 2024 study determined the orbital inclination of the planet, allowing its true mass to be d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gliese 581c
Gliese 581c (Gl 581c or GJ 581c) is an exoplanet orbiting within the Gliese 581 system. It is the second planet discovered in the system and the third in order from the star. With a mass about 6.8 times that of the Earth, it is classified as a super-Earth (a category of planets with masses greater than Earth's up to ten Earth masses). At the time of its discovery in 2007, Gliese 581c gained interest from astronomers because it was reported to be the first potentially Earth-like planet in the habitable zone of its star, with a temperature right for liquid water on its surface, and, by extension, potentially capable of supporting extremophile forms of Earth-like life. However, further research cast doubt upon the planet's habitability. Based on newer models of the habitable zone, the planet is likely too hot to be potentially habitable. In astronomical terms, the Gliese 581 system is relatively close to Earth, at in the direction of the constellation of Libra. This distance, alo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronal Mass Ejection
A coronal mass ejection (CME) is a significant ejection of plasma mass from the Sun's corona into the heliosphere. CMEs are often associated with solar flares and other forms of solar activity, but a broadly accepted theoretical understanding of these relationships has not been established. If a CME enters interplanetary space, it is sometimes referred to as an interplanetary coronal mass ejection (ICME). ICMEs are capable of reaching and colliding with Earth's magnetosphere, where they can cause geomagnetic storms, aurorae, and in rare cases damage to electrical power grids. The largest recorded geomagnetic perturbation, resulting presumably from a CME, was the solar storm of 1859. Also known as the ''Carrington Event'', it disabled parts of the newly created United States telegraph network, starting fires and electrically shocking some telegraph operators. Near solar maxima, the Sun produces about three CMEs every day, whereas near solar minima, there is about one CM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gliese 876 D
Gliese 876 d is an exoplanet away in the constellation of Aquarius. The planet was the third planet discovered orbiting the red dwarf Gliese 876, and is the innermost planet in the system. It was the lowest-mass known exoplanet apart from the pulsar planets orbiting PSR B1257+12 at the time of its discovery. Due to its low mass, it can be categorized as a super-Earth. Characteristics Mass, radius, and temperature The mass of any exoplanet from radial velocity has one problem, in that only a lower limit on the mass can be obtained. This is because the measured mass value also depends on the orbital inclination, which in general is unknown. However, in the case of Gliese 876, models incorporating the gravitational interactions between the resonant outer planets enables the inclination of the orbits to be determined. This reveals that the outer planets are nearly coplanar with an inclination of around 59° with respect to the plane of the sky. Assuming that Gliese 876 d orbits in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
