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Pavo (constellation)
Pavo is a constellation in the Southern Celestial Hemisphere, southern sky whose name is Latin for . Pavo first appeared on a 35-cm (14 in) diameter celestial globe published in 1598 in Amsterdam by Petrus Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas ''Uranometria'' of 1603, and was likely conceived by Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. French explorer and astronomer Nicolas-Louis de Lacaille gave its stars Bayer designations in 1756. The constellations Pavo, Grus (constellation), Grus, Phoenix (constellation), Phoenix and Tucana are collectively known as the "Southern Birds". The constellation's brightest member, Alpha Pavonis, is also known as Peacock and appears as a 1.91-Apparent magnitude, magnitude blue-white star, but is actually a spectroscopic binary. Delta Pavonis is a nearby Sun-like star some 19.9 light-years distant. Six of the star systems in Pavo have been found to host planets, inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peafowl
Peafowl is a common name for two bird species of the genus '' Pavo'' and one species of the closely related genus '' Afropavo'' within the tribe Pavonini of the family Phasianidae (the pheasants and their allies). Male peafowl are referred to as peacocks, and female peafowl are referred to as peahens. The two Asiatic species are the blue or Indian peafowl originally from the Indian subcontinent, and the green peafowl from Southeast Asia. The third peafowl species, the Congo peafowl, is native only to the Congo Basin. Male peafowl are known for their piercing calls and their extravagant plumage. The latter is especially prominent in the Asiatic species, which have an eye-spotted "tail" or "train" of covert feathers, which they display as part of a courtship ritual. The functions of the elaborate iridescent coloration and large "train" of peacocks have been the subject of extensive scientific debate. Charles Darwin suggested that they served to attract females, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranometria
is a star atlas produced by Johann Bayer. It was published in Augsburg in 1603 by Christoph Mang (''Christophorus Mangus'') under the full title (from Latin: ''Uranometria, containing charts of all the constellations, drawn by a new method and engraved on copper plates''). The word "uranometria", , literally translates to "measuring the heavens". It was the first atlas to cover the entire celestial sphere. Charts ''Uranometria'' contains 51 star charts, engraved on copper plates by Alexander Mair ( 1562–1617). The first 48 charts illustrate each of the 48 Ptolemaic constellations. The 49th chart introduces 12 new constellations in the deep southern sky, which was unknown to Ptolemy. The final two charts are planispheres labeled "''Synopsis coeli superioris borea''" and "''Synopsis coeli inferioris austrina''", or (roughly), "Overview of the northern celestial hemisphere" and "Overview of the southern celestial hemisphere". Each plate includes a grid for accurately deter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 181433
HD 181433 is a star with a system of orbiting exoplanets located in the southern constellation of Pavo (the Peacock). With an apparent visual magnitude of 8.40, it is too faint to be visible to the naked eye. It lies at a distance of 88 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of +40 km/s. The system shows a high proper motion, traversing the celestial sphere at an angular rate of . This K-type star has a stellar classification of K3III-IV, which presents it as an evolved star with mixed traits of a red giant and a subgiant. G. Campanella and associates list a class of K3IV. These are inconsistent with the fact that its luminosity is only 0.34 times that of the Sun. Its entry in the Hipparcos catalogue lists a spectral type of K5V, classifying it as an ordinary K-type main-sequence star, an orange dwarf. HD 181433 is an older star with age estimates of around 7 billion years. It is smaller than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star System
A star system or stellar system is a small number of stars that orbit each other, bound by gravity, gravitational attraction. It may sometimes be used to refer to a single star. A large group of stars bound by gravitation is generally called a ''star cluster'' or ''galaxy'', although, broadly speaking, they are also star systems. Star systems are not to be confused with planetary systems, which include planets and similar bodies (such as comets). Terminology A star system of two stars is known as a ''binary star'', ''binary star system'' or ''physical double star''. Systems with four or more components are rare, and are much less commonly found than those with 2 or 3. Multiple-star systems are called ''triple'', ''ternary'', or ''trinary'' if they contain three stars; ''quadruple'' or ''quaternary'' if they contain four stars; ''quintuple'' or ''quintenary'' with five stars; ''sextuple'' or ''sextenary'' with six stars; ''septuple'' or ''septenary'' with seven stars; and ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-year
A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days). Despite its inclusion of the word "year", the term should not be misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years). Definitions As defined by the International Astronomical Union (IAU), the light-year is the product of the Julian year (365.25 days, as opposed to the 365.2425-day Gregorian year or the 365.24219-day Tropical year that both approxim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Pavonis
Delta Pavonis is a single star in the southern constellation of Pavo. Its name is a Bayer designation that is Latinized from δ Pavonis, and abbreviated Delta Pav or δ Pav. It has an apparent visual magnitude of 3.56, making it a fourth-magnitude star that is visible to the naked eye from the southern hemisphere. Parallax measurements yield an estimated distance of from Earth. This makes it one of the nearest bright stars to the Solar System. It is approaching the Sun with a radial velocity of −23.5 km/s, and is predicted to come as close as in around 49,200 years. Physical characteristics This object is a subgiant of spectral type G8 IV; it will stop fusing hydrogen at its core relatively soon, starting the process of becoming a red giant. Hence, Delta Pavonis is 24% brighter than the Sun, but the effective temperature of its outer atmosphere is less: 5,571 K. Its mass is 107% of Sun's mass, with a radius 120% of Sun's radius. Delta Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopic Binary
A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars using a telescope, in which case they are called ''visual binaries''. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known. They may also be detected by indirect techniques, such as spectroscopy (''spectroscopic binaries'') or astrometry (''astrometric binaries''). If a binary star happens to orbit in a plane along our line of sight, its components will eclipse and transit each other; these pairs are called ''eclipsing binaries'', or, together with other binaries that change brightness as they orbit, ''photometric binaries''. If components in binary star systems are close enough, they can gravitationally distort each other's outer stellar atmospheres. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), extinction of the object's light caused by interstellar dust along the sightline, line of sight to the observer. Unless stated otherwise, the word ''magnitude'' in astronomy usually refers to a celestial object's apparent magnitude. The magnitude scale likely dates to before the ancient Ancient Greek astronomy#Astronomy in the Greco-Roman and Late Antique eras, Roman astronomer Ptolemy, Claudius Ptolemy, whose Star catalogue, star catalog popularized the system by listing stars from First-magnitude star, 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined to closely match this historical system by Norman Robert Pogson, Norman Pogson in 1856. The scale is reverse logarithmic scale, logarithmic: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tucana
Tucana (The Toucan) is a constellation in the southern sky, named after the toucan, a South American bird. It is one of twelve constellations conceived in the late sixteenth century by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. Tucana first appeared on a celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas ''Uranometria'' of 1603. French explorer and astronomer Nicolas Louis de Lacaille gave its stars Bayer designations in 1756. The constellations Tucana, Grus (constellation), Grus, Phoenix (constellation), Phoenix and Pavo (constellation), Pavo are collectively known as the "Southern Birds". Tucana is not a prominent constellation as all of List of stars in Tucana, its stars are third magnitude or fainter; the brightest is Alpha Tucanae with an apparent magnitude, apparent visual magnitude of 2.87. Beta Tucanae is a star system with six member stars, while Ka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phoenix (constellation)
Phoenix is a minor constellation in the southern sky. Named after the mythical Phoenix (mythology), phoenix, it was first depicted on a celestial atlas by Johann Bayer in his 1603 ''Uranometria''. The French explorer and astronomer Nicolas Louis de Lacaille charted the brighter stars and gave their Bayer designations in 1756. The constellation stretches from roughly −39° to −57° declination, and from 23.5h to 2.5h of right ascension. The constellations Phoenix, Grus (constellation), Grus, Pavo (constellation), Pavo and Tucana, are known as the Southern Birds. The brightest star, Alpha Phoenicis, is named Ankaa, an Arabic word meaning 'the Phoenix'. It is an orange giant of apparent magnitude 2.4. Next is Beta Phoenicis, actually a Binary star, binary system composed of two yellow giants with a combined apparent magnitude of 3.3. Nu Phoenicis has a dust disk, while the constellation has ten star systems with known planets and the recently discovered galaxy clusters El Gord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grus (constellation)
Grus (, or colloquially ) is a constellation in the southern sky. Its name is Latin for the crane (bird), crane, a type of bird. It is one of twelve constellations conceived by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. Grus first appeared on a celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas ''Uranometria'' of 1603. French explorer and astronomer Nicolas-Louis de Lacaille gave Bayer designations to its stars in 1756, some of which had been previously considered part of the neighbouring constellation Piscis Austrinus. The constellations Grus, Pavo (constellation), Pavo, Phoenix (constellation), Phoenix and Tucana are collectively known as the "Southern Birds". The constellation's brightest star, Alpha Gruis, is also known as Alnair and appears as a 1.7-Apparent magnitude, magnitude blue-white star. Beta Gruis is a red giant variable star with a minimum mag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayer Designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek alphabet, Greek or Latin letter followed by the genitive case, genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1564 stars. The brighter stars were assigned their first systematic names by the German astronomer Johann Bayer in 1603, in his star atlas ''Uranometria''. Bayer catalogued only a few stars too far south to be seen from Germany, but later astronomers (including Nicolas-Louis de Lacaille and Benjamin Apthorp Gould) supplemented Bayer's catalog with entries for southern constellations. Scheme Bayer assigned a lowercase Greek alphabet, Greek letter (alpha (α), beta (β), gamma (γ), etc.) or a Latin letter (A, b, c, etc.) to each star he catalogued, combined with the Latin name of the star's parent constellation in genitive case, genitive (possessive) form. The constellation name is frequently abbreviated to a standard three ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
