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Double Cluster
The Double Cluster, also known as Caldwell 14, consists of the open clusters NGC 869 and NGC 884 (often designated h Persei and χ (chi) Persei, respectively), which are close together in the constellation Perseus. Both visible to the naked eye, NGC 869 and NGC 884 lie at a distance of about in the Perseus Arm of the Milky Way galaxy. Membership NGC 869 has a mass of 4,700 solar masses and NGC 884 weighs in at 3,700 solar masses; both clusters are surrounded with a very extensive halo of stars, with a total mass for the complex of at least 20,000 solar masses. They form the core of the Perseus OB1 association of young hot stars. Based on their individual stars, the clusters are relatively young, both 14 million years old. In comparison, the Pleiades have an estimated age ranging from 75 million years to 150 million years. There are more than 300 blue-white supergiant stars in each of the clusters. The clusters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 869
NGC 869 (also known as h Persei) is an open cluster located around 7,460 light years away in the constellation of Perseus. The cluster is around 14 million years old. It is the west component of the Double Cluster with NGC 884. NGC 869 and 884 are often designated h and χ (chi) Persei, respectively. Some confusion surrounds what Bayer intended by these designations. It is sometimes claimed that Bayer did not resolve the pair into two patches of nebulosity, and that χ refers to the Double Cluster and h to a nearby star. Bayer's '' Uranometria'' chart for Perseus does not show them as nebulous objects, but his chart for Cassiopeia does, and they are described as ''Nebulosa Duplex'' in Schiller's '' Coelum Stellatum Christianum'', which was assembled with Bayer's help.Morton Wagman, ''Lost Stars'', McDonald & Woodward, 2003, , p. 240. The clusters are both located in the Perseus OB1 association, a few hundred light years apart from each other. The clusters were first recorded by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RS Persei
RS Persei is a red supergiant variable star located in the Double Cluster in Perseus constellation, Perseus. The star's apparent magnitude varies from 7.82 to 10.0, meaning it is never visible to the naked eye. It is a member of the cluster NGC 884, χ Persei, one half of the famous Double Cluster. Variability In March of 1904, Lidiya Tseraskaya discovered that the star, then referred to as BD+56°583, is a variable star. It was listed with its variable star designation, RS Persei, in Annie Jump Cannon, Annie Jump Cannon's 1907 work ''Second Catalog of Variable Stars''. RS Persei is classified as a semiregular variable star, with its brightness varying from magnitude 7.82 to 10.0 over 245 days, Detailed studies show that it also pulsates with a long secondary period variable, long secondary period of days. Properties RS Persei is a large cool star with a temperature of 3,500 K. Its size makes it luminous, although much of its radiation is emitted in the infrared. In 200 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiant (meteor Shower)
The radiant or apparent radiant of a meteor shower is the celestial point in the sky from which (from the point of view of a terrestrial observer) the paths of meteors appear to originate. The Perseids, for example, are meteors which appear to come from a point within the constellation of Perseus. Meteor paths appear at random locations in the sky, but the apparent paths of two or more meteors from the same shower will diverge from the radiant. The radiant is the vanishing point of the meteor paths, which are parallel lines in three-dimensional space, as seen from the perspective of the observer, who views a two-dimensional projection against the sky. The geometric effect is identical to crepuscular rays, where parallel sunbeams appear to diverge. A meteor that does not point back to the known radiant for a given shower is known as a ''sporadic'' and is not considered part of that shower. Shower meteors may appear a short time before the radiant has risen in the observer's ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassiopeia (constellation)
Cassiopeia () is a constellation and Asterism (astronomy), asterism in the northern sky named after the vain queen Cassiopeia (mother of Andromeda), Cassiopeia, mother of Andromeda (mythology), Andromeda, in Greek mythology, who boasted about her unrivaled beauty. Cassiopeia was one of the 48 constellations listed by the 2nd-century Greek astronomer Ptolemy, and it remains one of the 88 modern constellations today. It is easily recognizable due to its distinctive 'W' shape, formed by five bright stars. Cassiopeia is located in the northern sky and from latitudes above 34th parallel north, 34°N it is visible year-round. In the (sub)tropics it can be seen at its clearest from September to early November, and at low southern, tropical, latitudes of less than 25th parallel south, 25°S it can be seen, seasonally, low in the North. At magnitude 2.2, Alpha Cassiopeiae, or Schedar, is the brightest star in Cassiopeia. The constellation hosts some of the most luminous stars known, inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumpolar Star
A circumpolar star is a star that, as viewed from a given latitude on Earth, never sets below the horizon due to its apparent proximity to one of the celestial poles. Circumpolar stars are therefore visible from said location toward the nearest pole for the entire night on every night of the year (and would be continuously visible throughout the day too, were they not overwhelmed by the Sun's glare). Others are called ''seasonal'' stars. All circumpolar stars lie within a circumpolar circle whose size is determined by the observer's latitude. Specifically, the angular measure of the radius of this circle equals the observer's latitude. The closer the observer is to the North or South Pole, the larger its circumpolar circle. Before the definition of the Arctic was formalized as the region north of the Arctic Circle which experiences the midnight sun, it more broadly meant those places where the 'bear' constellations (Ursa Major, the Great Bear, and Ursa Minor, the Little Bear) we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelum Stellatum Christianum
The ''Coelum Stellatum Christianum'' is a star atlas published in 1627 by Julius Schiller ( 1580–1627), with the collaboration of Johann Bayer (1572–1625). In the treatise, which was published by Andreas Aperger at Augsburg during the same year as Schiller's death, pagan constellations were replaced with biblical figures and Christian motifs. Schiller replaced the zodiac constellations with the Twelve Apostles, the northern constellations with New Testament figures, and the southern constellations with Old Testament figures. The planets, the Sun, and the Moon were also replaced by biblical figures: *The Sun is replaced by Jesus Christ. *The Moon is replaced Mary (mother of Jesus), Mary. *Mercury (planet), Mercury is replaced by Elijah. *Venus is replaced by John the Baptist. *Mars is replaced by Joshua. *Jupiter is replaced by Moses. *Saturn is replaced by Adam. The engravings in the atlas were by Lucas Kilian. Constellations New Testament In general, New Testament figures an ... [...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] |
Johann Bayer
Johann Bayer (; 1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer). He was born in Rain in 1572. In 1592, aged 20, he began his study of philosophy and law at the University of Ingolstadt, after which he moved to Augsburg to begin work as a lawyer, becoming legal adviser to the city council in 1612. Bayer had several interests outside his work, including archaeology and mathematics. However, he is primarily known for his work in astronomy; particularly for his work on determining the positions of objects on the celestial sphere. He remained unmarried and died in 1625. Bayer's star atlas '' Uranometria Omnium Asterismorum'' (" Uranometry of all the asterisms") was first published in 1603 in Augsburg and dedicated to two prominent local citizens. This was the first atlas to cover the entire celestial sphere. It was based upon the work of Tycho Brahe and may have borrowed from Alessandro Piccolomini's 1540 star atlas, ''De le stelle fiss ... [...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] |
Cambridge University Press
Cambridge University Press was the university press of the University of Cambridge. Granted a letters patent by King Henry VIII in 1534, it was the oldest university press in the world. Cambridge University Press merged with Cambridge Assessment to form Cambridge University Press and Assessment under Queen Elizabeth II's approval in August 2021. With a global sales presence, publishing hubs, and offices in more than 40 countries, it published over 50,000 titles by authors from over 100 countries. Its publications include more than 420 academic journals, monographs, reference works, school and university textbooks, and English language teaching and learning publications. It also published Bibles, runs a bookshop in Cambridge, sells through Amazon, and has a conference venues business in Cambridge at the Pitt Building and the Sir Geoffrey Cass Sports and Social Centre. It also served as the King's Printer. Cambridge University Press, as part of the University of Cambridge, was a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Herschel
Frederick William Herschel ( ; ; 15 November 1738 – 25 August 1822) was a German-British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel. Born in the Electorate of Hanover, William Herschel followed his father into the military band of Hanover, before immigrating to Kingdom of Great Britain, Britain in 1757 at the age of nineteen. Herschel constructed his first large telescope in 1774, after which he spent nine years carrying out sky surveys to investigate double stars. Herschel published catalogues of nebulae in 1802 (2,500 objects) and in 1820 (5,000 objects). The resolving power of the Herschel telescopes revealed that many objects called nebulae in the Messier object, Messier catalogue were actually clusters of stars. On 13 March 1781 while making observations he made note of a new object in the constellation of Gemini. This would, after several weeks of verification and consultation with other astrono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Book Of Fixed Stars
''The Book of Fixed Stars'' ( ', literally ''The Book of the Shapes of Stars'') is an Astronomy, astronomical text written by Abd al-Rahman al-Sufi (Azophi) around 964. Following Graeco-Arabic translation movement, the translation movement in the 9th century AD, the book was written in Arabic language, Arabic, the common language for scholars across the vast Islamic territories, although the author himself was Persian people, Persian. It was an attempt to create a synthesis of the comprehensive star catalogue in Ptolemy's ''Almagest'' (books VII and VIII) with the indigenous Arabic astronomical traditions on the constellations (notably the Arabic constellation system of the ''Anwā). The original manuscript no longer survives as an Autograph (manuscript), autograph; however, the importance of tradition and the practice of diligence central to Islamic manuscript tradition have ensured the survival of the ''Book of Stars'' in later-made copies. Historical context The treatise w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
