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Olivier Chesneau
Olivier Chesneau (1972 in Mozé-sur-Louet – May 17, 2014 in Nice) was a French astronomer. He contributed to a better understanding of several aspects of evolved stars physics, especially planetary nebulae, massive stars and novae. Among other discoveries, Olivier Chesneau discovered the "peanut star" HR 5171, the fact that novae explode with an hourglass shape already a few days after outburst (e.g. RS Ophiuchi), or the detection of disks in the heart of planetary nebulae. The Laboratoire J Lagrange at the Côte d'Azur Observatory in France, and ESO The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental research organisation made up of 16 member states for ground-based ast ... established a prize in his memory, The Chesneau Prize. Minor planet 6065 Chesneau is named in his honor. References {{DEFAULTSORT:Chesneau, Olivier 21st-century French astr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mozé-sur-Louet
Mozé-sur-Louet () is a commune in the Maine-et-Loire department in western France. Population See also *Communes of the Maine-et-Loire department The following is a list of the 177 communes of the Maine-et-Loire department of France. The communes cooperate in the following intercommunalities (as of 2020):Mozesurlouet {{MaineLoire-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nice
Nice ( , ; Niçard: , classical norm, or , nonstandard, ; it, Nizza ; lij, Nissa; grc, Νίκαια; la, Nicaea) is the prefecture of the Alpes-Maritimes department in France. The Nice agglomeration extends far beyond the administrative city limits, with a population of nearly 1 millionDemographia: World Urban Areas , Demographia.com, April 2016 on an area of . Located on the , the southeastern coast of France on the , at the foot of the |
Ouest France
''Ouest-France'' ( ; French for "West-France") is a daily French newspaper known for its emphasis on both local and national news. The paper is produced in 47 different editions covering events in different French départments within the régions of Brittany, Lower Normandy and Pays de la Loire. Its readership has been unaffected by the decline of newspaper reading in France, unlike most other dailies. With 2.5 million daily readers (and a circulation of almost 800 000 units), it is by far the most read francophone newspaper in the world, ahead of French national newspapers ''Le Figaro'' and ''Le Monde''. History ''Ouest-France'' was founded in 1944 by Adolphe Le Goaziou and others following the closure of ''Ouest-Éclair'', which was banned by Liberation forces for collaborationism during the war.Jean-Loup Avril, ''Mille Bretons, dictionnaire biographique'', Les Portes du Large, Saint-Jacques-de-la-Lande, 2003, () It is based in Rennes and Nantes and has a circulation about 7 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, galaxies – in either observational astronomy, observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, Sun, solar astronomy, the Star formation, origin or stellar evolution, evolution of stars, or the galaxy formation and evolution, formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole. Types Astronomers usually fall under either of two main types: observational astronomy, observational and theoretical astronomy, theoretical. Observational astronomers make direct observations of Astronomical object, celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Nebulae
A planetary nebula (PN, plural PNe) is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelated to planets. The term originates from the planet-like round shape of these nebulae observed by astronomers through early telescopes. The first usage may have occurred during the 1780s with the English astronomer William Herschel who described these nebulae as resembling planets; however, as early as January 1779, the French astronomer Antoine Darquier de Pellepoix described in his observations of the Ring Nebula, "very dim but perfectly outlined; it is as large as Jupiter and resembles a fading planet". Though the modern interpretation is different, the old term is still used. All planetary nebulae form at the end of the life of a star of intermediate mass, about 1-8 solar masses. It is expected that the Sun will form a planetary neb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Massive Stars
This is a list of the most massive stars that have been discovered, in solar masses (). Uncertainties and caveats Most of the masses listed below are contested and, being the subject of current research, remain under review and subject to constant revision of their masses and other characteristics. Indeed, many of the masses listed in the table below are inferred from theory, using difficult measurements of the stars' temperatures and absolute brightnesses. All the masses listed below are uncertain: Both the theory and the measurements are pushing the limits of current knowledge and technology. Both theories and measurements could be incorrect. For example, VV Cephei could be between , or , depending on which property of the star is examined. Complications with distance and obscuring clouds Since massive stars are rare, astronomers must look very far from Earth to find them. All the listed stars are many thousands of light years away, which makes measurements difficult. In addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Novae
A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramatic appearance of a nova vary, depending on the circumstances of the two progenitor stars. All observed novae involve white dwarfs in close binary systems. The main sub-classes of novae are classical novae, recurrent novae (RNe), and dwarf novae. They are all considered to be cataclysmic variable stars. Classical nova eruptions are the most common type. They are likely created in a close binary star system consisting of a white dwarf and either a main sequence, subgiant, or red giant star. When the orbital period falls in the range of several days to one day, the white dwarf is close enough to its companion star to start drawing accreted matter onto the surface of the white dwarf, which creates a dense but shallow atmosphere. This atmosphe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HR 5171
V766 Centauri, also known as HR 5171, is a yellow hypergiant in the constellation Centaurus, either 5,000 or 12,000 light years from Earth. It is said to be either an extreme red supergiant (RSG) or recent post-red supergiant (Post-RSG) yellow hypergiant (YHG), both of which suggest it is one of the largest known stars. The star's diameter is uncertain but likely to be between 1,100 and 1,600 times that of the Sun. It was previously thought to be a contact binary, sharing a common envelope of material with a smaller yellow supergiant and secondary star, the two orbiting each other every 1,304 ± 6 days. However this has since been deemed unlikely. An optical companion, HR 5171B, may or may not be at the same distance as the yellow supergiant. System The HR 5171 system contains at least three stars. The primary A is an eclipsing binary (components Aa and Ab, or A and C in the Catalog of Components of Double and Multiple Stars) with two yellow stars in contact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hourglass
An hourglass (or sandglass, sand timer, sand clock or egg timer) is a device used to measure the passage of time. It comprises two glass bulbs connected vertically by a narrow neck that allows a regulated flow of a substance (historically sand) from the upper bulb to the lower one. Typically, the upper and lower bulbs are symmetric so that the hourglass will measure the same duration regardless of orientation. The specific duration of time a given hourglass measures is determined by factors including the quantity and coarseness of the particulate matter, the bulb size, and the neck width. Depictions of an hourglass as a symbol of the passage of time are found in art, especially on tombstones or other monuments, from antiquity to the present day. The form of a winged hourglass has been used as a literal depiction of the well-known idiom "time flies". History Antiquity The origin of the hourglass is unclear. Its predecessor the clepsydra, or water clock, is known to have exi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RS Ophiuchi
RS Ophiuchi (''RS Oph'') is a recurrent nova system approximately 5,000 light-years away in the constellation Ophiuchus. In its quiet phase it has an apparent magnitude of about 12.5. It has been observed to erupt in 1898, 1933, 1958, 1967, 1985, 2006 and 2021 and reached about magnitude 5 on average. A further two eruptions, in 1907 and 1945, have been inferred from archival data. The recurrent nova is produced by a white dwarf star and a red giant in a binary system. About every 15 years, enough material from the red giant builds up on the surface of the white dwarf to produce a thermonuclear explosion. The white dwarf orbits close to the red giant, with an accretion disc concentrating the overflowing atmosphere of the red giant onto the white dwarf. Properties RS Ophiuchi is a system consisting of a white dwarf with a red giant companion. The stars are in a binary system with an orbital period of around 454 days. Eruptive history The chart below shows when every recor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Côte D'Azur Observatory
The Côte d'Azur Observatory (french: Observatoire de la Côte d'Azur, OCA) is a network of astronomical observatories throughout southern France. It originated in 1988 with the merger of two observatories: # Nice Observatory # Centre de recherches en géodynamique et astrométrie (CERGA) Cote d'Azure Observatory tested beam combining technology at CHARA array. Astronomers developed a theory about M-Type asteroids, that may be tested by the planned spacecraft ''Psyche''. See also * List of astronomical observatories This is a list of astronomical observatories ordered by name, along with initial dates of operation (where an accurate date is available) and location. The list also includes a final year of operation for many observatories that are no longer in ... * Lunar Laser Ranging Experiment * OCA-DLR Asteroid Survey References External links Côte d'Azur Observatory official website (English version) [...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 about 730 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 un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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