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HD 131399
HD 131399 is a star system in the constellation of Centaurus. Based on the system's electromagnetic spectrum, it is located around 350 light-years (107.9 parsecs) away. The total apparent magnitude is 7.07, but because of interstellar dust between it and the Earth, it appears 0.22 ± 0.09 magnitudes dimmer than it should. The brightest star, is a young A-type main-sequence star, and further out are two lower-mass stars. A Jupiter-mass planet or a low-mass brown dwarf was once thought to be orbiting the central star, but this has been ruled out. Stellar system The brightest star in the HD 131399 system is designated HD 131399 A. Its spectral type is A1V, and it is 2.08 times as massive as the Sun. The two lower-mass stars are designated HD 131399 B and C, respectively. B is a G-type main-sequence star, while HD 131399 C is a K-type main-sequence star. Both stars are less massive than the Sun. HD 131399 B and C are located very close to each ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPHERE Observations Of The Planet HD 131399Ab
A sphere (from Greek , ) is a surface analogous to the circle, a curve. In solid geometry, a sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the center (geometry), ''center'' of the sphere, and the distance is the sphere's ''radius''. The earliest known mentions of spheres appear in the work of the Greek mathematics, ancient Greek mathematicians. The sphere is a fundamental surface in many fields of mathematics. Spheres and nearly-spherical shapes also appear in nature and industry. Bubble (physics), Bubbles such as soap bubbles take a spherical shape in equilibrium. The Earth is spherical Earth, often approximated as a sphere in geography, and the celestial sphere is an important concept in astronomy. Manufactured items including pressure vessels and most curved mirrors and lenses are based on spheres. Spheres rolling, roll smoothly in any direction, so most balls used in sports and toys are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemically Peculiar Star
In astrophysics, chemically peculiar stars (CP stars) are stars with distinctly unusual Metallicity, metal abundances, at least in their surface layers. Classification Chemically peculiar stars are common among hot main-sequence (hydrogen-burning) stars. These hot peculiar stars have been divided into four main classes on the basis of their spectra, although two classification systems are sometimes used: * non-magnetic metallic-lined star, metallic-lined (Am, CP1) * Ap and Bp stars, magnetic (Ap, CP2) * non-magnetic mercury-manganese star, mercury-manganese (HgMn, CP3) * Helium-weak star, helium-weak (He-weak, CP4). The class names provide a good idea of the peculiarities that set them apart from other stars on or near the main sequence. The Am stars (CP1 stars) show weak lines of singly ionized Calcium, Ca and/or Scandium, Sc, but show enhanced abundances of heavy metals. They also tend to be slow rotators and have an effective temperature between 7000 and . The Ap stars (CP2 st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Cincinnati
The University of Cincinnati (UC or Cincinnati, informally Cincy) is a public university, public research university in Cincinnati, Ohio, United States. It was founded in 1819 and had an enrollment of over 53,000 students in 2024, making it the second-largest university in Ohio. It is part of the University System of Ohio. The university's primary uptown campus and medical campus are located in the List of Cincinnati neighborhoods, Heights and Corryville, Cincinnati, Corryville neighborhoods, with branch campuses located in University of Cincinnati Clermont College, Batavia and University of Cincinnati Blue Ash College, Blue Ash, Ohio. The university has 14 constituent colleges, with programs in University of Cincinnati College of Design, Architecture, Art, and Planning, architecture, Carl H. Lindner College of Business, business, University of Cincinnati College of Education Criminal Justice and Human Services, education, University of Cincinnati College of Engineering and Appli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daniel Apai
Daniel Apai (born 1977) is an astrophysicist at The University of Arizona in Tucson, Arizona. He is known for his studies of astrobiology, extrasolar planets, planetary atmospheres, space telescope technology, and the formation of planetary systems. He is the principal investigator of thEarths in Other Solar Systemsteam of NASA's '' Nexus for Exoplanet System Studies'' and the Hubble Space Telescope Cloud Atlas Treasury program, anProject EDEN a large survey for habitable planets in the immediate solar neighborhood. He is leading the Nautilus Space Observatory space telescope concept and co-leading the technology development underpinning it. Career Daniel Apai was born in Szeged, Hungary in 1977 and grew up in Budapest, Hungary. He studied physics at the University of Szeged, Hungary and the University of Jena, Germany, and received a diploma as research physicist in 2000. After graduation, he was awarded a German Academic Exchange Service Doctoral Fellowship and began his doct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Dwarf
A white dwarf is a Compact star, stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very density, dense: in an Earth sized volume, it packs a mass that is comparable to the Sun. No nuclear fusion takes place in a white dwarf; what light it radiates is from its residual heat. The nearest known white dwarf is Sirius B, at 8.6 light years, the smaller component of the Sirius binary star. There are currently thought to be eight white dwarfs among the hundred star systems nearest the Sun. The unusual faintness of white dwarfs was first recognized in 1910. The name ''white dwarf'' was coined by Willem Jacob Luyten in 1922. White dwarfs are thought to be the final stellar evolution, evolutionary state of stars whose mass is not high enough to become a neutron star or black hole. This includes over 97% of the stars in the Milky Way. After the hydrogen-stellar nucleosynthesis, fusing period of a main sequence, main-sequence star of Stellar mass, lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Giant Branch
The red-giant branch (RGB), sometimes called the first giant branch, is the portion of the giant branch before helium ignition occurs in the course of stellar evolution. It is a stage that follows the main sequence for low- to intermediate-mass stars. Red-giant-branch stars have an inert helium core surrounded by a shell of hydrogen fusing via the CNO cycle. They are K- and M-class but much larger and more luminous than main-sequence stars of the same temperature. Discovery Red giants were identified early in the 20th century when the use of the Hertzsprung–Russell diagram made it clear that there were two distinct types of cool stars with very different sizes: dwarfs, now formally known as the main sequence; and giant star, giants. The term ''red-giant branch'' came into use during the 1940s and 1950s, although initially just as a general term to refer to the red-giant region of the Hertzsprung–Russell diagram. Although the basis of a thermonuclear main-sequence lifetime, fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-type Star
An object with the spectral type T (also called T dwarf or methane brown dwarf) is either a brown dwarf or young free-floating planetary-mass object. A directly imaged exoplanet with a young age can also be a T-dwarf. T dwarfs are colder than L dwarfs, but warmer than Y dwarfs. Prototype Gliese 229B The first T-dwarf discovered was Gliese 229B, which was discovered in 1995. This object had a temperature below 1000 K and showed methane (CH4), water vapor (H2O) and carbon monoxide (CO) in its spectrum. In the upper atmosphere CO is converted into CH4 and H2O, while the opposite is true for the hotter lower atmosphere. It also showed absorption due to caesium (Cs), but absorption features commonly found in M-dwarfs ( CaH, FeH, TiO, and VO) were missing. Ammonia (NH3) was included in the analysis of the spectrum. Sodium (Na) and potassium (K) are also detected in this T-dwarf. Later work found a dynamical mass of 70 ± 5 for Gliese 229B, which is much higher than the coolin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chile
Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Pacific Ocean. Chile had a population of 17.5 million as of the latest census in 2017 and has a territorial area of , sharing borders with Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage to the south. The country also controls several Pacific islands, including Juan Fernández Islands, Juan Fernández, Isla Salas y Gómez, Desventuradas Islands, Desventuradas, and Easter Island, and claims about of Antarctica as the Chilean Antarctic Territory. The capital and largest city of Chile is Santiago, and the national language is Spanish language, Spanish. Conquest of Chile, Spain conquered and colonized the region in the mid-16th century, replacing Incas in Central Chile, Inca rule; however, they Arauco War ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atacama Desert
The Atacama Desert () is a desert plateau located on the Pacific Ocean, Pacific coast of South America, in the north of Chile. Stretching over a strip of land west of the Andes Mountains, it covers an area of , which increases to if the barren lower slopes of the Andes are included. The Atacama Desert is the driest nonpolar desert in the world, and the second driest overall, behind some specific spots within the McMurdo Dry Valleys. It is the only Desert climate, true desert to receive less precipitation than polar deserts, and the largest fog desert in the world. The area has been used as an experimentation site for Mars expedition simulations due to its similarities to the Martian environment. The constant Inversion (meteorology), temperature inversion caused by the cool north-flowing Humboldt Current, Humboldt ocean current and the strong South Pacific High, Pacific anticyclone contribute to the extreme aridity of the desert. The most arid region of the Atacama Desert is s ... [...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] |
Very Large Telescope
The Very Large Telescope (VLT) is an astronomical facility operated since 1998 by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each equipped with a primary mirror that measures in diameter. These optical telescopes, named ''Antu'', ''Kueyen'', ''Melipal'', and ''Yepun'' (all words for astronomical objects in the Mapuche language), are generally used separately but can be combined to achieve a very high angular resolution. The VLT array is also complemented by four movable Auxiliary Telescopes (ATs) with apertures. The VLT is capable of observing both visible and infrared wavelengths. Each individual telescope can detect objects that are roughly four billion times fainter than what can be seen with the naked eye. When all the telescopes are combined, the facility can achieve an angular resolution of approximately 0.002 arcsecond. In single telescope mode, the angular resol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectro-Polarimetric High-Contrast Exoplanet Research
Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT-SPHERE) is an adaptive optics system and coronagraphic facility at the Very Large Telescope (VLT). It provides direct imaging as well as spectroscopic and polarimetric characterization of exoplanet systems. The instrument operates in the visible and near infrared, achieving exquisite image quality and contrast over a small field of view around bright targets. Results from SPHERE complement those from other planet finder projects, which include HARPS, CoRoT, and the Kepler Mission. The instrument was installed on Unit Telescope "Melipal" (UT3) and achieved First light (astronomy), first light in May, 2014. At the time of installation, it was the latest of a series of second generation VLT-instruments such as Very Large Telescope#Instruments, X-shooter, K-band Multi-Object Spectrograph, KMOS and Multi Unit Spectroscopic Explorer, MUSE. Science goals Direct imaging of exoplanets is extremely challenging: # The brightnes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
