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Kojima-1Lb
Kojima-1Lb (TCP J05074264+2447555) is an exoplanet discovered trough the microlensing method. The host star lens was discovered by the amateur astronomer Tadashi Kojima (小嶋正). As of November 2019 it is the planet around the brightest microlensing host star and consequently around a nearby star, as opposed to most of the microlensing planets, which are usually found around distant and inaccessible host stars. Kojima-1Lb is a mildly cold Neptune around a red dwarf located from the solar system. Naming The microlensing event was first reported on CBAT as TCP J05074264+2447555 by Kojima. Conventionally microlensing planets are named after the discoverer of the microlensing event and not after the discoverer of the planetary feature. The discovery group of the planetary feature nicknamed the microlensing event Feynman-01 in honour of the Osservatorio Astroficico R.P. Feynman that discovered the planetary feature. The star now appears as Kojima-1 in SIMBAD. Discovery Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Astronomy
Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers make contributions in doing citizen science, such as by monitoring variable stars, double stars, sunspots, or occultations of stars by the Moon or asteroids, or by discovering transient astronomical events, such as comets, galactic novae or supernovae in other galaxies. Amateur astronomers do not use the field of astronomy as their primary source of income or support, and usually have no professional degree in astrophysics or advanced academic training in the subject. Most amateurs are hobbyists, while others have a high degree of experience in astronomy and may often assist and work alongside professional astronomers. Many astronomers have studied the sky throughout history in an amateur framework; however, since the beginning of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitational Microlensing
Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect. It can be used to detect objects that range from the mass of a planet to the mass of a star, regardless of the light they emit. Typically, astronomers can only detect bright objects that emit much light (stars) or large objects that block background light (clouds of gas and dust). These objects make up only a minor portion of the mass of a galaxy. Microlensing allows the study of objects that emit little or no light. When a distant star or quasar gets sufficiently aligned with a massive compact foreground object, the bending of light due to its gravitational field, as discussed by Albert Einstein in 1915, leads to two distorted images (generally unresolved), resulting in an observable magnification. The time-scale of the transient brightening depends on the mass of the foreground object as well as on the relative proper motion between the background 'source' and the foreground 'lens' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-type Main-sequence Star
An F-type main-sequence star (F V) is a main-sequence, hydrogen-fusing star of spectral type F and luminosity class V. These stars have from 1.0 to 1.4 times the mass of the Sun and surface temperatures between 6,000 and 7,600 K.Tables VII and VIII. This temperature range gives the F-type stars a whitish hue when observed by the atmosphere. Because a main-sequence star is referred to as a dwarf star, this class of star may also be termed a yellow-white dwarf (not to be confused with white dwarfs, remnant stars that are a possible final stage of stellar evolution). Notable examples include Procyon A, Gamma Virginis A and B, and KIC 8462852. Spectral standard stars The revised Yerkes Atlas system (Johnson & Morgan 1953) listed a dense grid of F-type dwarf spectral standard stars; however, not all of these have survived to this day as stable standards. The ''anchor points'' of the MK spectral classification system among the F-type main-sequence dwarf stars, i.e. those standa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanets Detected By Microlensing
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. 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 in 5 Sun-like starsFor the purpose of this 1 in 5 statistic, "Sun-like" means G-type star. Data for Sun-like stars was not available so this statistic is an extrapolation from data about K-type stars. have an "Earth-sized"For the purpose of this 1 in 5 statistic, Earth-sized means 1–2 Earth radii. planet in the habitable zone.F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taurus (constellation)
Taurus (Latin for "the Bull") is one of the constellations of the zodiac and is located in the northern celestial hemisphere. Taurus is a large and prominent constellation in the Northern Hemisphere's winter sky. It is one of the oldest constellations, dating back to the Early Bronze Age at least, when it marked the location of the Sun during the spring equinox. Its importance to the agricultural calendar influenced various bull figures in the mythologies of Ancient Sumer, Akkad, Assyria, Babylon, Egypt, Greece, and Rome. Its old astronomical symbol is (♉︎), which resembles a bull's head. A number of features exist that are of interest to astronomers. Taurus hosts two of the nearest open clusters to Earth, the Pleiades and the Hyades, both of which are visible to the naked eye. At first magnitude, the red giant Aldebaran is the brightest star in the constellation. In the northeast part of Taurus is Messier 1, more commonly known as the Crab Nebula, a supernova remnant co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sky & Telescope
''Sky & Telescope'' (''S&T'') is a monthly American magazine covering all aspects of amateur astronomy, including the following: *current events in astronomy and space exploration; *events in the amateur astronomy community; *reviews of astronomical equipment, books, and computer software; *amateur telescope making; and *astrophotography. The articles are intended for the informed lay reader and include detailed discussions of current discoveries, frequently by participating scientists. The magazine is illustrated in full color, with both amateur and professional photography of celestial sights, as well as tables and charts of upcoming celestial events. History ''Sky & Telescope'' was founded by Charles A Federer and his wife Helen Spence Federer and began publication at Harvard College Observatory in November 1941, as a result of the merger of the separate magazines, '' The Sky'' and '' The Telescope''. In 2005, Sky Publishing Corporation was acquired by New Track Media, a portfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subaru Telescope
is the telescope of the National Astronomical Observatory of Japan, located at the Mauna Kea Observatory on Hawaii. It is named after the open star cluster known in English as the Pleiades. It had the largest monolithic primary mirror in the world from its commissioning until 2005. Overview The Subaru Telescope is a Ritchey-Chretien reflecting telescope. Instruments can be mounted at a Cassegrain focus below the primary mirror; at either of two Nasmyth focal points in enclosures on the sides of the telescope mount, to which light can be directed with a tertiary mirror; or at the prime focus in lieu of a secondary mirror, an arrangement rare on large telescopes, to provide a wide field of view suited to deep wide-field surveys. In 1984, the University of Tokyo formed an engineering working group to develop and study the concept of a telescope. In 1985, the astronomy committee of Japan's science council gave top priority to the development of a "Japan National Large Tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doppler Spectroscopy
Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star. 1,018 extrasolar planets (about 19.5% of the total) have been discovered using Doppler spectroscopy, as of November 2022. History Otto Struve proposed in 1952 the use of powerful spectrographs to detect distant planets. He described how a very large planet, as large as Jupiter, for example, would cause its parent star to wobble slightly as the two objects orbit around their center of mass. He predicted that the small Doppler shifts to the light emitted by the star, caused by its continuously varying radial velocity, would be detectable by the most sensitive spectrographs as tiny redshifts and blueshifts in the star's emission. However, the technology of the time produced radial-velocity meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ESPRESSO
Espresso (, ) is a coffee-brewing method of Italian origin, in which a small amount of nearly boiling water (about ) is forced under of pressure through finely-ground coffee beans. Espresso can be made with a wide variety of coffee beans and roast degrees. Espresso is the most common way of making coffee in southern Europe, especially in Italy, France, Spain, and Portugal. It is also popular in Switzerland, Croatia, Bosnia and Herzegovina, Bulgaria, Greece, South Africa, the United Kingdom, the United States, Canada, Australia and New Zealand. Espresso is generally thicker than coffee brewed by other methods, with a viscosity similar to that of warm honey. This is due to the higher concentration of suspended and dissolved solids, and the ''crema'' on top (a foam with a creamy consistency). As a result of the pressurized brewing process, the flavors and chemicals in a typical cup of espresso are very concentrated. Espresso has more caffeine per unit volume than most coffee be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptive Optics
Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of incoming wavefront distortions by deforming a mirror in order to compensate for the distortion. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, in microscopy, optical fabrication and in retinal imaging systems to reduce optical aberrations. Adaptive optics works by measuring the distortions in a wavefront and compensating for them with a device that corrects those errors such as a deformable mirror or a liquid crystal array. Adaptive optics should not be confused with active optics, which works on a longer timescale to correct the primary mirror geometry. Other methods can achieve resolving power exceeding the limit imposed by atmospheric distortion, such as speckle imaging, aperture synthesis, and lucky imaging, or by moving outside the atmosphere with space telescopes, such as the Hubble Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frost Line (astrophysics)
In astronomy or planetary science, the frost line, also known as the snow line or ice line, is the particular distance in the solar nebula from the central protostar where it is cold enough for volatile compounds such as water, ammonia, methane, carbon dioxide, and carbon monoxide to condense into solid ice grains. Each volatile substance has its own snow line (e.g. carbon monoxide, nitrogen, and argon), so it is important to always specify which material's snow line is meant. A tracer gas may be used for materials that are difficult to detect; for example diazenylium for carbon monoxide. The term is borrowed from the notion of "frost line" in soil science. Location Different volatile compounds have different condensation temperatures at different partial pressures (thus different densities) in the protostar nebula, so their respective frost lines will differ. The actual temperature and distance for the snow line of water ice depend on the physical model used to calculate it a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits the Sun, from a maximum (aphelion) to a minimum (perihelion) and back again once each year. The astronomical unit was originally conceived as the average of Earth's aphelion and perihelion; however, since 2012 it has been defined as exactly (see below for several conversions). The astronomical unit is used primarily for measuring distances within the Solar System or around other stars. It is also a fundamental component in the definition of another unit of astronomical length, the parsec. History of symbol usage A variety of unit symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union (IAU) had used the symbol ''A'' to denote a length equal to the astronomical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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