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XO-4
XO-4 is a star located approximately 896 light-years away from Earth in the Lynx (constellation), Lynx constellation. It has a Apparent magnitude, magnitude of about 11 and cannot be seen with the naked eye but is visible through a small telescope. A search for a binary companion star using adaptive optics at MMT Observatory was negative. The star XO-4 is named Koit. The name was selected in the NameExoWorlds campaign by Estonia, during the 100th anniversary of the International Astronomical Union, IAU. Koit is Estonian for ''dawn'', and was named for a character in a folk tale written by Friedrich Robert Faehlmann. Planetary system One known exoplanet, XO-4b, which is classified as a hot jupiter, orbits XO-4. This exoplanet was discovered in 2008 by the XO Telescope project using the Methods of detecting extrasolar planets#Transit method, transit method. It has been named Hämarik, meaning ''dusk'', and referring to a character from the same Faehlmann story featuring Koit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XO-4b
XO-4b is an extrasolar planet approximately 956 light years away in the constellation of Lynx (constellation), Lynx. This planet was found by the transit method by McCullough in May 2008. The planet has mass and radius . This planet orbits very close to the Stellar classification#Class F, F-type parent star, as it is typical for transiting planets, classing this planet as Hot Jupiter. Orbit It takes only 4.125 days (or 99 hours) to orbit at a distance of 8.3 gigameters (0.0555 astronomical unit, AU) away from the star. The study in 2012, utilizing a Rossiter–McLaughlin effect, have determined the planetary orbit is strongly misaligned with the equatorial plane of the star, misalignment equal to -46.7°. Naming The planet XO-4b is named Hämarik. The name was selected in the NameExoWorlds campaign by Estonia, during the 100th anniversary of the International Astronomical Union, IAU. Hämarik is Estonian for dusk, and was named for a character in a folk tale written by Friedrich ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OLPC XO-4
The OLPC XO (formerly known as $100 Laptop, Children's Machine, 2B1) is a low cost laptop computer intended to be distributed to children in developing countries around the world, to provide them with access to knowledge, and opportunities to "explore, experiment and express themselves" (constructionist learning). The XO was developed by Nicholas Negroponte, a co-founder of MIT's Media Lab, and designed by Yves Behar's Fuseproject company. The laptop is manufactured by Quanta Computer and developed by One Laptop per Child (OLPC), a non-profit 501(c)(3) organization. The subnotebooks were designed for sale to government-education systems which then would give each primary school child their own laptop. Pricing was set to start at $188 in 2006, with a stated goal to reach the $100 mark in 2008 and the 50-dollar mark by 2010. When offered for sale in the Give One Get One campaigns of Q4 2006 and Q4 2007, the laptop was sold at $199. The rugged, low-power computers use flash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lynx (constellation)
Lynx is a constellation named after the animal, usually observed in the Northern Celestial Hemisphere. The constellation was introduced in the late 17th century by Johannes Hevelius. It is a faint constellation, with its brightest stars forming a zigzag line. The orange giant Alpha Lyncis is the brightest star in the constellation, and the semiregular variable star Y Lyncis is a target for amateur astronomers. Six star systems have been found to contain planets. Those of 6 Lyncis and HD 75898 were discovered by the Doppler method; those of XO-2, XO-4, XO-5 and WASP-13 were observed as they passed in front of the host star. Within the constellation's borders lie NGC 2419, an unusually remote globular cluster; the galaxy NGC 2770, which has hosted three recent Type Ib supernovae; the distant quasar APM 08279+5255, whose light is magnified and split into multiple images by the gravitational lensing effect of a foreground galaxy; and the Lynx Supercluster, which was the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XO Telescope
The XO Telescope is an astronomical telescope located on the 3,054 m (10,000 foot) summit of Haleakala on Maui, Hawaii. It consists of two 200-millimeter telephoto camera lenses, and resembles binoculars in shape. It is used by the XO Project to detect extrasolar planets using the transit method. It is similar to the TrES survey telescope. The construction of the one-of-a-kind telescope cost $60,000 for the hardware, and much more than that for the associated software. Planets discovered The ''XO telescope'' has discovered six objects so far, five are hot Jupiter planets and one, XO-3b, may be a brown dwarf. All were discovered using the transit method. ''Light green rows indicate that the planet orbits one of the stars in a binary star system.'' See also * List of extrasolar planets A subset of XO light curves are available at the NASA Exoplanet Archive. Other Ground-Based Transit Surveys * Next-Generation Transit Survey * Trans-Atlantic Exoplanet Survey or ''TrES'' * H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MMT Observatory
The MMT Observatory (MMTO) is an astronomical observatory on the site of Fred Lawrence Whipple Observatory (IAU observatory code 696). The Whipple observatory complex is located on Mount Hopkins, Arizona, US (55 km south of Tucson) in the Santa Rita Mountains. The observatory is operated by the University of Arizona and the Smithsonian Institution, and has a visitor center in nearby Amado, Arizona. The MMTO is the home of the MMT (formerly Multiple Mirror Telescope), which has a primary mirror 6.5 m in diameter. The name comes from the six smaller mirrors originally used before the single primary mirror was installed in 1998. The primary mirror has a special lightweight honeycomb design made by the University of Arizona's Steward Observatory Mirror Laboratory. The MMT is housed in a building which allows the walls and roof around the telescope to be completely rolled back, allowing it to cool down very quickly in order to improve observation. Multiple Mirror Telescope (197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-type Main-sequence Stars
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] |
Methods Of Detecting Extrasolar Planets
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 light from the parent star causes a glare that washes it out. For those reasons, very few of the exoplanets reported have been observed directly, with even fewer being resolved from their host star. Instead, astronomers have generally had to resort to indirect methods to detect extrasolar planets. As of 2016, several different indirect methods have yielded success. Established detection methods The following methods have at least once proved successful 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 move ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Jupiter
Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere temperatures resulted in their informal name "hot Jupiters". Hot Jupiters are the easiest extrasolar planets to detect via the radial-velocity method, because the oscillations they induce in their parent stars' motion are relatively large and rapid compared to those of other known types of planets. One of the best-known hot Jupiters is . Discovered in 1995, it was the first extrasolar planet found orbiting a Sun-like star. has an orbital period of about 4 days. General characteristics Though there is diversity among hot Jupiters, they do share some common properties. * Their defining characteristics are their large masses and short orbital periods, spanning 0.36–11.8 Jupiter masses and 1.3–111 Earth days. The mass c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanet
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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Robert Faehlmann
Friedrich Robert Faehlmann (Fählmann) (31 December 1798 in Ao Manor, Kreis Jerwen – 22 April 1850 in Tartu) was an Estonian writer, medical doctor and philologist active in Livonia, Russian Empire. He was a co-founder of the Learned Estonian Society at the University of Dorpat and its chairman (1843-1850). He was born to the family of the manager of Ao Manor (now in Väike-Maarja Parish) in Kreis Jerwen. In 1825 he graduated from the medical department of the University of Dorpat. In 1827 he earned the M.D. degree and become a physician in Dorpat (now Tartu). In addition he gave lectures in the Estonian language at the university during 1842–1850. In the 1820s he became interested in Estonian culture and, in 1838, became a co-founder of the Learned Estonian Society. He brought attention to Estonian folklore, notably the Kalevipoeg which, since his death, has become the Estonian national epic, thanks to the efforts of another Estophile, Friedrich Reinhold Kreutzwald. He a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded in 1919 and is based in Paris, France. The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. As of 2018, the Union had over 13,700 individual members, spanning 90 countries, and 82 national members. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estonia
Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, and to the east by Lake Peipus and Russia. The territory of Estonia consists of the mainland, the larger islands of Saaremaa and Hiiumaa, and over 2,200 other islands and islets on the eastern coast of the Baltic Sea, covering a total area of . The capital city Tallinn and Tartu are the two largest urban areas of the country. The Estonian language is the autochthonous and the official language of Estonia; it is the first language of the majority of its population, as well as the world's second most spoken Finnic language. The land of what is now modern Estonia has been inhabited by '' Homo sapiens'' since at least 9,000 BC. The medieval indigenous population of Estonia was one of the last " pagan" civilisations in Europe to adopt Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
