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Canopus (star)
Canopus is the brightest star in the southern constellation of Carina and the second-brightest star in the night sky. It is also designated α Carinae, which is Latinised to Alpha Carinae. With a visual apparent magnitude of −0.74, it is outshone only by Sirius. Located around from the Sun, Canopus is a bright giant of spectral type A9, so it is essentially white when seen with the naked eye. It has a luminosity over 10,000 times the luminosity of the Sun, is eight times as massive, and has expanded to 71 times the Sun's radius. Its enlarged photosphere has an effective temperature of around . Canopus is undergoing core helium burning and is currently in the so-called blue loop phase of its evolution, having already passed through the red-giant branch after exhausting the hydrogen in its core. Canopus is a source of X-rays, which are likely being emitted from its corona. The prominent appearance of Canopus means it has been the subject of mytholog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canopus
Canopus is the brightest star in the southern constellation of Carina (constellation), Carina and the list of brightest stars, second-brightest star in the night sky. It is also Bayer designation, designated α Carinae, which is Latinisation of names, Latinised to Alpha Carinae. With a visual apparent magnitude of −0.74, it is outshone only by Sirius. Located around from the Sun, Canopus is a bright giant of spectral type A9, so it is essentially white when seen with the naked eye. It has a luminosity over 10,000 times the luminosity of the Sun, is eight times as mass of the Sun, massive, and has expanded to 71 times the Sun's radius. Its enlarged photosphere has an effective temperature of around . Canopus is undergoing stellar core, core helium fusion, helium burning and is currently in the so-called blue loop phase of its stellar evolution, evolution, having already passed through the red-giant branch after exhausting the hydrogen in its core. Canopus is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Core
A stellar core is the extremely hot, dense region at the center of a star. For an ordinary main sequence star, the core region is the volume where the temperature and pressure conditions allow for energy production through thermonuclear fusion of hydrogen into helium. This energy in turn counterbalances the mass of the star pressing inward; a process that self-maintains the conditions in thermal and hydrostatic equilibrium. The minimum temperature required for stellar hydrogen fusion exceeds 107 K (), while the density at the core of the Sun is over . The core is surrounded by the stellar envelope, which transports energy from the core to the stellar atmosphere where it is radiated away into space. Main sequence Main sequence stars are distinguished by the primary energy-generating mechanism in their central region, which joins four hydrogen nuclei to form a single helium atom through thermonuclear fusion. The Sun is an example of this class of stars. Once stars with the mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vedas
upright=1.2, The Vedas are ancient Sanskrit texts of Hinduism. Above: A page from the '' Atharvaveda''. The Vedas (, , ) are a large body of religious texts originating in ancient India. Composed in Vedic Sanskrit, the texts constitute the oldest layer of Sanskrit literature and the oldest scriptures of Hinduism. There are four Vedas: the Rigveda, the Yajurveda, the Samaveda and the Atharvaveda. Each Veda has four subdivisions – the Samhitas (mantras and benedictions), the Aranyakas (text on rituals, ceremonies, sacrifices and symbolic-sacrifices), the Brahmanas (commentaries on rituals, ceremonies and sacrifices), and the Upanishads (texts discussing meditation, philosophy and spiritual knowledge).Gavin Flood (1996), ''An Introduction to Hinduism'', Cambridge University Press, , pp. 35–39A Bhattacharya (2006), ''Hindu Dharma: Introduction to Scriptures and Theology'', , pp. 8–14; George M. Williams (2003), Handbook of Hindu Mythology, Oxford University Press, , p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agastya
Agastya ( kn, ಅಗಸ್ತ್ಯ, ta, அகத்தியர், sa, अगस्त्य, te, అగస్త్యుడు, ml, അഗസ്ത്യൻ, hi, अगस्त्य) was a revered Indian sage of Hinduism. In the Indian tradition, he is a noted recluse and an influential scholar in diverse languages of the Indian subcontinent. He and his wife Lopamudra are the celebrated authors of hymns 1.165 to 1.191 in the Sanskrit text ''Rigveda'' and other Vedic literature. Agastya is considered to be the father of Siddha medicine. Agastya appears in numerous itihasas and Puranas including the major ''Ramayana'' and ''Mahabharata''. He is one of the seven most revered rishis (the Saptarishi) in the Vedic texts, and is revered as one of the Tamil Siddhar in the Shaivism tradition, who invented an early grammar of the Old Tamil language, Agattiyam, playing a pioneering role in the development of Tampraparniyan medicine and spirituality at Saiva centres in pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acronychal Rising
The heliacal rising ( ) or star rise of a star occurs annually, or the similar phenomenon of a planet, when it first becomes visible above the eastern horizon at dawn just before sunrise (thus becoming "the morning star") after a complete orbit of the earth around the sun. Historically, the most important such rising is that of Sirius, which was an important feature of the Egyptian calendar and astronomical development. The rising of the Pleiades heralded the start of the Ancient Greek sailing season, using celestial navigation. Cause and significance Relative to the stars, the sun appears to drift eastward about one degree per day along a path called the ecliptic because there are 360 degrees in any complete revolution (circle), which takes about 365 days in the case of one revolution of the earth around the sun. Any given "distant" star in the belt of the ecliptic will be visible at night for only half of the year, when it will always remain below the horizon. During the ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sparta
Sparta ( Doric Greek: Σπάρτα, ''Spártā''; Attic Greek: Σπάρτη, ''Spártē'') was a prominent city-state in Laconia, in ancient Greece. In antiquity, the city-state was known as Lacedaemon (, ), while the name Sparta referred to its main settlement on the banks of the Eurotas River in Laconia, in south-eastern Peloponnese. Around 650 BC, it rose to become the dominant military land-power in ancient Greece. Given its military pre-eminence, Sparta was recognized as the leading force of the unified Greek military during the Greco-Persian Wars, in rivalry with the rising naval power of Athens. Sparta was the principal enemy of Athens during the Peloponnesian War (431–404 BC), from which it emerged victorious after the Battle of Aegospotami. The decisive Battle of Leuctra in 371 BC ended the Spartan hegemony, although the city-state maintained its political independence until its forced integration into the Achaean League in 192 BC. The city nevertheless ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menelaus
In Greek mythology, Menelaus (; grc-gre, Μενέλαος , 'wrath of the people', ) was a king of Mycenaean (pre- Dorian) Sparta. According to the ''Iliad'', Menelaus was a central figure in the Trojan War, leading the Spartan contingent of the Greek army, under his elder brother Agamemnon, king of Mycenae. Prominent in both the ''Iliad'' and ''Odyssey'', Menelaus was also popular in Greek vase painting and Greek tragedy, the latter more as a hero of the Trojan War than as a member of the doomed House of Atreus. Description In the account of Dares the Phrygian, Menelaus was described as ". . .of moderate stature, auburn-haired, and handsome. He had a pleasing personality." Family Menelaus was a descendant of Pelops son of Tantalus. He was the younger brother of Agamemnon, and the husband of Helen of Troy. According to the usual version of the story, followed by the ''Iliad'' and ''Odyssey'' of Homer, Agamemnon and Menelaus were the sons of Atreus, king of Mycenae and Ae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canopus (mythology)
In Greek mythology, Canopus or Canobus (Ancient Greek: Κάνωβος) was the pilot of the ship of King Menelaus of Sparta during the Trojan War. Mythology Canopus is described as a handsome young man who was loved by the Egyptian prophetess, Theonoe, but never reciprocated her feelings. According to legend, while visiting the Egyptian coast, Canopus was bitten by a serpent and died. His master, Menelaus, erected a monument to him at one of the mouths of the River Nile, around which the town of Canopus later developed.Strabo, ''Geographica'' 17.1.17 Legacy Also named for Canopus is Canopus, the brightest star in the southern constellation of Carina (the ''keel'' of the ship Argo), and the second-brightest star in the night sky, after Sirius. Notes References * Conon'', Fifty Narrations, surviving as one-paragraph summaries in the Bibliotheca (Library) of Photius, Patriarch of Constantinople'' translated from the Greek by Brady KieslingOnline version at the Topos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Mythology
A major branch of classical mythology, Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the Cosmogony, origin and Cosmology#Metaphysical cosmology, nature of the world, the lives and activities of List of Greek mythological figures, deities, Greek hero cult, heroes, and List of Greek mythological creatures, mythological creatures, and the origins and significance of the ancient Greeks' own cult (religious practice), cult and ritual practices. Modern scholars study the myths to shed light on the religious and political institutions of ancient Greece, and to better understand the nature of myth-making itself. The Greek myths were initially propagated in an oral tradition, oral-poetic tradition most likely by Minoan civilization, Minoan and Mycenaean Greece, Mycenaean singers starting in the 18th century BC; eventually the myths of the heroes of the Trojan War and its after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Corona
A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma. The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar eclipse, but it is also observable with a coronagraph. Spectroscopic measurements indicate strong ionization in the corona and a plasma temperature in excess of , much hotter than the surface of the Sun, known as the photosphere. The word ''corona'' is , in turn derived . History In 1724, French-Italian astronomer Giacomo F. Maraldi recognized that the aura visible during a solar eclipse belongs to the Sun, not to the Moon. In 1809, Spanish astronomer José Joaquín de Ferrer coined the term 'corona'. Based in his own observations of the 1806 solar eclipse at Kinderhook (New York), de Ferrer also proposed that the corona was part of the Sun and not of the Moon. English astronomer Norman Lockyer identified the first element unknown o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red-giant Branch
The red-giant branch (RGB), sometimes called the first giant branch, is the portion of the giant branch before helium ignition occurs in the course of stellar evolution. It is a stage that follows the main sequence for low- to intermediate-mass stars. Red-giant-branch stars have an inert helium core surrounded by a shell of hydrogen fusing via the CNO cycle. They are K- and M-class stars much larger and more luminous than main-sequence stars of the same temperature. Discovery Red giants were identified early in the 20th century when the use of the Hertzsprung–Russell diagram made it clear that there were two distinct types of cool stars with very different sizes: dwarfs, now formally known as the main sequence; and giants. The term ''red-giant branch'' came into use during the 1940s and 1950s, although initially just as a general term to refer to the red-giant region of the Hertzsprung–Russell diagram. Although the basis of a thermonuclear main-sequence lifetime, followed by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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