15-459: The protecting Mother Camels (Arabic العوائذ alʽawaʼid ) is an asterism in the constellation of Draco described by ancient Arabic nomadic tribes. The asterism was interpreted as a ring of mother camels – Beta Draconis (Rastaban), Gamma Draconis (Eltanin), Nu Draconis (Kuma) and Xi Draconis (Grumium) – surrounding a foal (the faint star Alruba ), with another mother camel, Mu Draconis (Alrakis) running to join them. The Arabs did not see
30-534: A more general concept than the 88 formally defined constellations . Constellations are based on asterisms, but unlike asterisms, constellations outline and today completely divide the sky and all its celestial objects into regions around their central asterisms. For example, the asterism known as the Big Dipper or the Plough comprises the seven brightest stars in the constellation Ursa Major . Another asterism
45-459: 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
60-434: Is the triangle , within the constellation of Capricornus . Asterisms range from simple shapes of just a few stars to more complex collections of many stars covering large portions of the sky. The stars themselves may be bright naked-eye objects or fainter, even telescopic, but they are generally all of a similar brightness to each other. The larger brighter asterisms are useful for people who are familiarizing themselves with
75-567: The Galactic Center . Some asterisms refer to portions of traditional constellation figures. These include: Other asterisms are also composed of stars from one constellation, but do not refer to the traditional figures. Other asterisms that are formed from stars in more than one constellation. Asterisms range from the large and obvious to the small, and even telescopic. Johann Bayer Johann Bayer ( German pronunciation: [ˈjoːhan ˈbaɪɐ] ; 1572 – 7 March 1625)
90-709: The International Astronomical Union (IAU) precisely divided the sky into 88 official constellations following geometric boundaries encompassing all of the stars within them. Any additional new selected groupings of stars or former constellations are often considered as asterisms. However, technical distinctions between the terms 'constellation' and 'asterism' often remain somewhat ambiguous. Some asterisms consist completely of bright first-magnitude stars , which mark out simple geometric shapes. Other asterisms consist partially of multiple first-magnitude stars. All other first-magnitude stars are
105-717: The Vedanga Jyotisha and the Babylonians . Different cultures identified different constellations, although a few of the more obvious patterns tend to appear in the constellations of multiple cultures, such as those of Orion and Scorpius . As anyone could arrange and name a grouping of stars there was no distinct difference between a constellation and an asterism . For example, Pliny the Elder mentions 72 asterisms in his book Naturalis Historia . A general list containing 48 constellations likely began to develop with
120-436: The astronomer Hipparchus (c. 190 – c. 120 BCE). As constellations were considered to be composed only of the stars that constituted the figure, it was always possible to use any leftover stars to create and squeeze in a new grouping among the established constellations. Exploration by Europeans to other parts of the globe exposed them to stars previously unknown to them. Two astronomers particularly known for greatly expanding
135-484: The constellation Draco as it is now. The Mother Camels were protecting the foal from the attack of two wolves or jackals – Zeta Draconis (Aldhibah) and Eta Draconis (Athebyne). The faint pair Omega Draconis and 27 Draconis was known as the "wolf's claws" (الأظفار الذئب al-ʼaẓfār al-dhiʼb ). Asterism (astronomy) An asterism is an observed pattern or group of stars in the sky . Asterisms can be any identified pattern or group of stars, and therefore are
150-465: 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 fisse ("Of the fixed stars"), although Bayer included an additional 1,000 stars. The Uranometria introduced a new system of star designation which has become known as the Bayer designation . Bayer's atlas included twelve new constellations invented
165-521: The night sky. The patterns of stars seen in asterisms are not necessarily a product of any physical association between the stars, but are rather the result of the particular perspectives of their observations. For example the Summer Triangle is a purely observational physically unrelated group of stars, but the stars of Orion's Belt are all members of the Orion OB1 association and five of
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#1732783680106180-424: The number of southern constellations were Johann Bayer (1572–1625) and Nicolas Louis de Lacaille (1713–1762). Bayer had listed twelve figures made out of stars that were too far south for Ptolemy to have seen. Lacaille created 14 new groups, mostly for the area surrounding South Celestial Pole . Many of these proposed constellations have been formally accepted, but the rest have remained as asterisms. In 1928,
195-791: The only such stars in their asterisms or constellations, with Canopus in the Argo Navis asterism south of Sirius, visually east of the Carina Nebula and near the Large Magellanic Cloud (both being first-magnitude deep-sky objects), Achernar in the Eridanus constellation east of Canopus, Fomalhaut in the Southern Fish constellation east of Achernar and Antares in the Scorpius constellation visually near
210-586: The seven stars of the Big Dipper are members of the Ursa Major Moving Group . Physical associations, such as the Hyades or Pleiades , can be asterisms in their own right and part of other asterisms at the same time. In many early civilizations, it was common to associate groups of stars in connect-the-dots stick-figure patterns. Some of the earliest records are those of ancient India in
225-515: 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
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