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GJ 1214
GJ 1214 (sometimes Gliese 1214) is a dim Stellar classification#Class M, M4.5 red dwarf star in the constellation Ophiuchus with an apparent magnitude of 14.7. It is located at a distance of from Earth. GJ 1214 hosts one known exoplanet. Nomenclature The designation ''GJ 1214'' comes from the Gliese Catalogue of Nearby Stars. This star was first included in the second edition of the catalogue, published in 1979 by Wilhelm Gliese, Gliese and Hartmut Jahreiß, Jahreiß, hence the ''GJ'' prefix usually used for this star. In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project. The approved names, proposed by a team from Kenya, were announced in June 2023. GJ 1214 is named Orkaria and its planet is named Enaiposha, after the Maasai language, Maa words for red ochre and for a large body of water, alluding to the color of the star and likely composition of the planet. Properties GJ 1214 is about one-fifth the radius o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GJ1214b (Artist’s Impression)
(sometimes , also named Enaiposha since 2023) is an exoplanet that orbits the star GJ 1214, discovered in December 2009. Its parent star is from the Sun, in the constellation Ophiuchus. At the time of its discovery, was the most likely known candidate for being an ocean planet. For that reason, scientists at that time often called the planet a "waterworld". However, a recent study of the planet's internal structure informed by observations taken with the James Webb Space Telescope suggests that a "waterworld" composition is implausible and the planet is more likely to host a thick gaseous envelope consisting of hydrogen, helium, water and other volatile chemicals such as methane or carbon dioxide. It is a mini-Neptune, meaning it is larger than Earth but is significantly smaller (in mass and radius) than the gas giants of the Solar System. After CoRoT-7b, it was the second planet between Earth and Neptune in mass to have both its mass and radius measured and is the first of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Activity
A stellar magnetic field is a magnetic field generated by the motion of conductive Plasma (physics), plasma inside a star. This motion is created through convection, which is a form of energy transport involving the physical movement of material. A localized magnetic field exerts a force on the plasma, effectively increasing the pressure without a comparable gain in density. As a result, the magnetized region rises relative to the remainder of the plasma, until it reaches the star's photosphere. This creates starspots on the surface, and the related phenomenon of coronal loops. Measurement A star's magnetic field can be measured using the Zeeman effect. Normally the atoms in a star's atmosphere will absorb certain frequencies of energy in the electromagnetic spectrum, producing characteristic dark absorption lines in the spectrum. However, when the atoms are within a magnetic field, these lines become split into multiple, closely spaced lines. The energy also becomes Polarizati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CoRoT-7
CoRoT-7 (TYC 4799-1733-1) is a binary star system made up of a late G-type star and a M-dwarf star that was discovered in 2021. The primary star has three exoplanets, including CoRoT-7b, a super-Earth exoplanet that is remarkable due to its extremely high temperature (around 2000°C) and very short orbital period, around 20 hours. It was the first exoplanet shown to be rocky. The system has the name CoRoT-7 after the CoRoT space telescope, which discovered the exoplanets around the star CoRoT-7A. The stellar system is 520 light-years from the Earth. Stellar components CoRoT-7A The primary, CoRoT-7A is a G-type main sequence star, slightly smaller, cooler, and younger than the Sun. It has an apparent magnitude of 11.67, fainter than Proxima Centauri (mag. 11.05), the nearest star to the Sun, and is far too faint to be seen with the naked eye. This star is approximately 520 light-years away from the Solar System in the constellation Monoceros (the Unicorn). CoRoT-7B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methods Of Detecting Extrasolar Planets
Methods of detecting exoplanets usually rely on indirect strategies – that is, they do not directly image the planet but deduce its existence from another signal. Any planet is an extremely faint light source compared to its parent star. For example, a star like the Sun is about a billion times as bright as the reflected light from any of the planets orbiting it. In addition to the intrinsic difficulty of detecting such a faint light source, the glare from the parent star washes it out. For those reasons, very few of the exoplanets reported have been detected directly, with even fewer being resolved from their host star. Established detection methods The following methods have proven successful at least once for discovering a new planet or detecting an already discovered planet: Radial velocity A star with a planet will move in its own small orbit in response to the planet's gravity. This leads to variations in the speed with which the star moves toward or away from Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Silla Observatory
La Silla Observatory is an astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several other telescopes are also located at the site and are partly maintained by ESO. The observatory is one of the largest in the Southern Hemisphere and was the first in Chile to be used by ESO. The La Silla telescopes and instruments are located 150 km northeast of La Serena, on the outskirts of the Atacama Desert, one of the driest and most remote areas in the world. Like other observatories in this region, La Silla is far from sources of light pollution and, like the Paranal Observatory—home to the Very Large Telescope—it has some of the darkest night skies on Earth. History Following the decision in 1963 to approve Chile as the site for the ESO observatory, scouting parties were sent to various locations to assess their suitability. The site that was decided upon was La Silla in the southern part of the Atacama Des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Southern Observatory
The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 member states for ground-based astronomy. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky. The organisation employs over 750 staff members and receives annual member state contributions of approximately €162 million. Its observatories are located in northern Chile. ESO has built and operated some of the largest and most technologically advanced telescopes. These include the 3.6 m New Technology Telescope, an early pioneer in the use of active optics, and the Very Large Telescope (VLT), which consists of four individual 8.2 m telescopes and four smaller auxiliary telescopes which can all work together or separately. The Atacama Large Millimeter Array observes the u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Accuracy Radial Velocity Planet Searcher
The High Accuracy Radial Velocity Planet Searcher (HARPS) is a high-precision echelle planet-finding spectrograph installed in 2002 on the ESO's 3.6m telescope at La Silla Observatory in Chile. The first light was achieved in February 2003. HARPS has discovered over 130 exoplanets to date, with the first one in 2004, making it the most successful planet finder behind the Kepler space telescope. It is a second-generation radial-velocity spectrograph, based on experience with the ELODIE and CORALIE instruments. Characteristics The HARPS can attain a precision of 0.97 m/s (3.5 km/h), making it one of only two instruments worldwide with such accuracy. This is due to a design in which the target star and a reference spectrum from a thorium lamp are observed simultaneously using two identical optic fibre feeds, and to careful attention to mechanical stability: the instrument sits in a vacuum vessel which is temperature-controlled to within 0.01 kelvins. The precision ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MEarth Project
The MEarth Project (pronounced ''mirth'') is a NSF-funded project in the United States. It is a robotic exoplanet observatory that is part of the Fred Lawrence Whipple Observatory on Mount Hopkins in Arizona. The project monitors the brightness of thousands of red dwarf stars with the goal of finding transiting planets. As red dwarf stars are small, any transiting planet blocks a larger proportion of starlight than transits around a Sun-like star would, allowing smaller planets to be detected through ground-based observations. Equipment The original MEarth-North observatory on Mount Hopkins consists of eight RC Optical Systems 9 Ritchey-Chrétien telescopes equipped with 2048 × 2048 Apogee U42 CCDs, infrared filters, and equatorial mounts. It began operation in January 2008. In 2014, the MEarth-South observatory began operations at the Cerro Tololo Inter-American Observatory site east of La Serena, Chile, extending MEarth's coverage to the southern celestial hemisphe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mini-Neptune
A Mini-Neptune (sometimes known as a gas dwarf or transitional planet) is a planet less massive than Neptune but resembling Neptune in that it has a thick hydrogen-helium atmosphere, probably with deep layers of ice, rock or liquid oceans (made of water, ammonia, a mixture of both, or heavier volatiles). A gas dwarf is a gas planet with a rocky core that has accumulated a thick envelope of hydrogen, helium, and other Volatile (astrogeology), volatiles, having, as a result, a total radius between 1.7 and 3.9 Earth radii (). The term is used in a three-tier, metallicity-based classification regime for short-period exoplanets, which also includes the rocky, Terrestrial planet, terrestrial-like planets with less than and planets greater than , namely ice giants and gas giants. Properties Theoretical studies of such planets are loosely based on knowledge about Uranus and Neptune. Without a thick atmosphere, they would be classified as an ocean planet instead. An estimated dividing li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super-Earth
A super-Earth is a type of exoplanet with a mass higher than Earth, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17.1 times Earth's, respectively. The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or Planetary habitability, habitability. The alternative term "gas dwarfs" may be more accurate for those at the higher end of the mass scale, although "mini-Neptunes" is a more common term. Definition In general, super-Earths are defined by their masses. The term does not imply temperatures, compositions, orbital properties, habitability, or environments. While sources generally agree on an upper bound of 10 Earth masses (~69% of the mass of Uranus, which is the Solar System's giant planet with the least mass), the lower bound varies from 1 or 1.9 to 5, with various other definitions appearing in the popular media. The term "super-Earth" is also used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GJ 1214 B
(sometimes , also named Enaiposha since 2023) is an exoplanet that orbits the star GJ 1214, discovered in December 2009. Its parent star is from the Sun, in the constellation Ophiuchus. At the time of its discovery, was the most likely known candidate for being an ocean planet. For that reason, scientists at that time often called the planet a "waterworld". However, a recent study of the planet's internal structure informed by observations taken with the James Webb Space Telescope suggests that a "waterworld" composition is implausible and the planet is more likely to host a thick gaseous envelope consisting of hydrogen, helium, water and other volatile chemicals such as methane or carbon dioxide. It is a mini-Neptune, meaning it is larger than Earth but is significantly smaller (in mass and radius) than the gas giants of the Solar System. After CoRoT-7b, it was the second planet between Earth and Neptune in mass to have both its mass and radius measured and is the first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extrasolar Planet
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 Extraterrestrial atmosphere, composition, Natural environment, environmental conditions, and Extraterrestrial life, potential for life. There are many methods of detecting exoplanets. Astronomical transit, 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 tida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
