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Alcor–Mizar
Mizar and Alcor are two stars forming a naked eye double in the handle of the Big Dipper (or Plough) asterism in the constellation of Ursa Major. Mizar is the second star from the end of the Big Dipper's handle, and Alcor its fainter companion. The traditional name Mizar derives from the Arabic المئزر miʼzar meaning 'apron; wrapper, covering, cover'. Alcor was originally Arabic سها Suhā/Sohā, meaning either the ‘forgotten’ or ‘neglected’ one; notable as a faintly perceptible companion of Mizar. Mizar, also designated Zeta Ursae Majoris (ζ Ursae Majoris, abbreviated Zeta UMa, ζ UMa), is itself a quadruple system and Alcor, also designated 80 Ursae Majoris (80 UMa), is a binary, the pair together forming a sextuple system. The whole system lies about 83 light-years away from the Sun, as measured by the Hipparcos astrometry satellite. Stellar system With normal eyesight Alcor appears at about 12 minutes of arc from Mizar. Alcor is of magnit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Star
A binary star 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 using a telescope as separate stars, 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 their mutual outer stellar atmospheres. In some cases, thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipper
Dippers are members of the genus ''Cinclus'' in the bird family Cinclidae, so-called because of their bobbing or dipping movements. They are unique among passerines for their ability to dive and swim underwater. Taxonomy The genus ''Cinclus'' was introduced by the German naturalist Moritz Balthasar Borkhausen in 1797 with the white-throated dipper (''Cinclus cinclus'') as the type species. The name ''cinclus'' is from the Ancient Greek word ''kinklos'' that was used to describe small tail-wagging birds that resided near water. ''Cinclus'' is the only genus in the family Cinclidae. The white-throated dipper and American dipper are also known in Britain and America, respectively, as the ''water ouzel'' (sometimes spelt "ousel") – ouzel originally meant the only distantly related but superficially similar Eurasian blackbird (Old English ''osle''). Ouzel also survives as the name of a relative of the blackbird, the ring ouzel. The genus contains five species: *White-throated d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eta Ursae Majoris
Eta Ursae Majoris ( Latinised from η Ursae Majoris, abbreviated Eta UMa, η UMa), formally named Alkaid , is a star in the constellation of Ursa Major. It is the most eastern (leftmost) star in the Big Dipper (or Plough) asterism. However, unlike most stars of the Big Dipper, it is not a member of the Ursa Major moving group. With an apparent visual magnitude of +1.84, it is the third-brightest star in the constellation and one of the brightest stars in the night sky. Physical properties Eta Ursae Majoris is a 10-million-year-old B-type main sequence star with a stellar classification of B3 V. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. It has six times the mass; 3.4 times the radius, and is radiating around 594 times as much energy as the Sun. Its outer atmosphere has an effective temperature of about 15,540 K, giving it the blue-white hue of a B-type star. This star ... [...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, Lower Bavaria, in 1572. At twenty, in 1592 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eques (ancient Rome)
The ''equites'' (; literally "horse-" or "cavalrymen", though sometimes referred to as "knights" in English) constituted the second of the property-based classes of ancient Rome, ranking below the senatorial class. A member of the equestrian order was known as an ''eques'' (). Description During the Roman kingdom and the first century of the Roman Republic, legionary cavalry was recruited exclusively from the ranks of the patricians, who were expected to provide six ''centuriae'' of cavalry (300 horses for each consular legion). Around 400BC, 12 more ''centuriae'' of cavalry were established and these included non-patricians (plebeians). Around 300 BC the Samnite Wars obliged Rome to double the normal annual military levy from two to four legions, doubling the cavalry levy from 600 to 1,200 horses. Legionary cavalry started to recruit wealthier citizens from outside the 18 ''centuriae''. These new recruits came from the first class of commoners in the Centuriate Assembly orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the Roman Republic it became the dominant language in the Italian region and subsequently throughout the Roman Empire. Even after the fall of Western Rome, Latin remained the common language of international communication, science, scholarship and academia in Europe until well into the 18th century, when other regional vernaculars (including its own descendants, the Romance languages) supplanted it in common academic and political usage, and it eventually became a dead language in the modern linguistic definition. Latin is a highly inflected language, with three distinct genders (masculine, feminine, and neuter), six or seven noun cases (nominative, accusative, genitive, dative, ablative, and vocative), five declensions, four verb conjuga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greece
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of culturally and linguistically related city-states and other territories. Most of these regions were officially unified only once, for 13 years, under Alexander the Great's empire from 336 to 323 BC (though this excludes a number of Greek city-states free from Alexander's jurisdiction in the western Mediterranean, around the Black Sea, Cyprus, and Cyrenaica). In Western history, the era of classical antiquity was immediately followed by the Early Middle Ages and the Byzantine period. Roughly three centuries after the Late Bronze Age collapse of Mycenaean Greece, Greek urban poleis began to form in the 8th century BC, ushering in the Archaic period and the colonization of the Mediterranean Basin. This was followed by the age of Classical G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabic Star Names
This is a list of Arabic star names. In Western astronomy, most of the accepted star names are Arabic, a few are Greek language, Greek and some are of unknown origin. Typically only bright stars have names. History of Arabic star names Very old star names originated among people who lived in the Arabian Peninsula more than a thousand years ago, after the rise of Islam. However, some Arabic language star names sprang up later in history, as translations of ancient Greek language descriptions. The astronomer Ptolemy, Claudius Ptolemy in his ''Almagest'' (2nd century) tabulated the celestial position and brightness (visual magnitude) of 1,025 stars. Ptolemy's book was translated into Arabic in the 8th and 9th centuries and became famous in Europe as a 12th-century Latin translation. Many of the Arabic-language star descriptions in the ''Almagest'' came to be widely used as names for stars. Ptolemy used a strategy of "figure reference" to identify stars according to their position w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hindu
Hindus (; ) are people who religiously adhere to Hinduism.Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pages 35–37 Historically, the term has also been used as a geographical, cultural, and later religious identifier for people living in the Indian subcontinent. The term ''"Hindu"'' traces back to Old Persian which derived these names from the Sanskrit name ''Sindhu'' (सिन्धु ), referring to the river Indus. The Greek cognates of the same terms are "''Indus''" (for the river) and "''India''" (for the land of the river). The term "''Hindu''" also implied a geographic, ethnic or cultural identifier for people living in the Indian subcontinent around or beyond the Sindhu (Indus) River. By the 16th century CE, the term began to refer to residents of the subcontinent who were not Turkic or Muslims. Hindoo is an archaic spelling variant, whose use today is considered derogatory. The historical development of Hindu self-identity within the local In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Astronomy
Astronomy has long history in Indian subcontinent stretching from pre-historic to modern times. Some of the earliest roots of Indian astronomy can be dated to the period of Indus Valley civilisation or earlier. Astronomy later developed as a discipline of Vedanga, or one of the "auxiliary disciplines" associated with the study of the Vedas,Sarma (2008), ''Astronomy in India'' dating 1500 BCE or older. The oldest known text is the ''Vedanga Jyotisha'', dated to 1400–1200 BCE (with the extant form possibly from 700 to 600 BCE). Indian astronomy was influenced by Greek astronomy beginning in the 4th century BCEHighlights of Astronomy, Volume 11B: As presented at the XXIIIrd General Assembly of the IAU, 1997. Johannes Andersen Springer, 31 January 1999 – Science – 616 pages. page 72/ref>Babylon to Voyager and Beyond: A History of Planetary Astronomy. David Leverington. Cambridge University Press, 29 May 2010 – Science – 568 pages. page 4/ref>The History and Practice of Anci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arundhati (Hinduism)
Arundhati ( sa, अरुन्धती, translit=Arundhatī) is the wife of the sage Vasishtha, one of the seven sages ( Saptarshi) of Hinduism. Etymology The name in Sanskrit literally means 'washed from the rays of sun', from 'sun rays', and , 'washed'. Legend Arundhati's birth and life are mentioned in various Hindu scriptures. The birth of Arundhati is found in the Shiva Purana and Bhagavata Purana. The instruction by Brahma to Arundhati is described in the Uttara Kanda of the Ramcharitmanas. The rivalry between Vishvamitra and Vasishtha which leads to the death of her hundred sons is described in the Balakanda of Valmiki's Ramayana. The Mahabharata and several Brahmana works describe her sons, including Shakti, and grandson Parashara. Arundhati's meetings with Sita and Rama are mentioned in the Ramayana, Ramcharitmanas and Vinaya Patrika.Rambhadracharya 1994, pp. ''iii—vi''. Her role in pleading Shiva to marry Parvati is described in the sixth canto of Kuma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saptarishi
The Saptarishi () are the seven rishis of ancient India who are extolled in the Vedas, and other Hindu literature. The Vedic Samhitas never enumerate these rishis by name, although later Vedic texts such as the Brahmanas and Upanisads do so. Hinduism An early prototype of the "Saptarishi" concept may stem from the six families associated with the six "Family Books" in the Rigveda Samhita (Mandalas 2–7 in ascending order: Gṛtsamāda, Viśvāmitra, Vāmadeva, Atri, Bhardwaja, Vasiṣṭha). While not a "Family Book", Mandala 8 is mostly attributed to Kaṇva, who could be considered the 7th prototypical Saptarishi. The earliest formal list of the seven rishis is given by Jaiminiya Brahmana 2.218–221: Agastya, Atri, Bhardwaja, Gautama, Jamadagni, Vashistha, and Vishvamitra followed by Brihadaranyaka Upanisad 2.2.6 with a slightly different list: Atri, Bharadwaja, Gautama, Jamadagni, Kashyapa, Vashistha, and Vishvamitra. The late Gopatha Brahmana 1.2.8 has Vashisth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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