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Bestla (moon)
Bestla or Saturn XXXIX is a retrograde irregular moon of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on 4 May 2005, from observations taken between 13 December 2004 and 5 March 2005. Description Bestla is about 7 kilometres in diameter, and orbits Saturn at an average distance of 20,192,000 km in 1088 days, at an inclination of 147° to the ecliptic (151° to Saturn's equator), in a retrograde direction and with an eccentricity of 0.5145. Early observations from 2005 suggested that Bestla had a very high eccentricity of 0.77. Like many of the outer irregular moons of the giant planets, Bestla's eccentricity may vary as a result of the Kozai mechanism. Bestla's rotation period is hours. Like Kiviuq, it is likely to be a contact binary or binary object, as its light curve has strong variation in brightness and a plateau-like maximum not seen in the other irregulars. Name This moon was named in April 2007 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassini (spacecraft)
Cassini may refer to: People * Cassini (surname) * Oleg Cassini (1913-2006), American fashion designer :Cassini family: * Giovanni Domenico Cassini (1625–1712), Italian mathematician, astronomer, engineer, and astrologer * Jacques Cassini (1677–1756), French astronomer, son of Giovanni Domenico Cassini * César-François Cassini de Thury (1714–1784), French astronomer and cartographer, son of Jacques Cassini * Jean-Dominique, comte de Cassini (1748–1845), French astronomer, son of César-François Cassini de Thury * Alexandre Henri Gabriel de Cassini (1781–1832), French botanist and naturalist, son of Jean-Dominique de Cassini Planetary science * Cassini's laws on the motion of the Moon * Cassini Division, a gap in the rings of Saturn * ''Cassini–Huygens'', the space mission to examine Saturn and its moons, of which the ''Cassini'' orbiter was a part * Cassini (Martian crater) * Cassini (lunar crater) * 24101 Cassini, an asteroid * 24102 Jacquescassini, another aster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kozai Mechanism
In celestial mechanics, the Kozai mechanism is a dynamical phenomenon affecting the orbit of a binary system perturbed by a distant third body under certain conditions. It is also known as the von Zeipel-Kozai-Lidov, Lidov–Kozai mechanism, Kozai–Lidov mechanism, or some combination of Kozai, Lidov–Kozai, Kozai–Lidov or von Zeipel-Kozai-Lidov effect, oscillations, cycles, or resonance. This effect causes the orbit's argument of pericenter to oscillate about a constant value, which in turn leads to a periodic exchange between its eccentricity and inclination. The process occurs on timescales much longer than the orbital periods. It can drive an initially near-circular orbit to arbitrarily high eccentricity, and ''flip'' an initially moderately inclined orbit between a prograde and a retrograde motion. The effect has been found to be an important factor shaping the orbits of irregular satellites of the planets, trans-Neptunian objects, extrasolar planets, and multiple star s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discoveries By Scott S
Discoveries may refer to: Music * ''Discoveries'' (Cannonball Adderley album), 1955 * ''Discoveries'' (Josh Nelson album), 2011 * ''Discoveries'' (Northlane album), 2011 Other uses * ''Discoveries'' (film), a 1939 British film * Discoveries (horse), a racehorse * ''Discoveries'' (Robertson Davies), a 2002 book by Robertson Davies * ''Discoveries'' (TV series), a Canadian youth science television series which aired on CBC Television in 1957 * ''Abrams Discoveries'', a series of illustrated non-fiction books published by Harry N. Abrams * ''Discoveries'', a work by William Butler Yeats, written in 1907 * ''Discoveries'', a magazine published by Cedars-Sinai Medical Center See also * Age of Discoveries * Discovery (other) Discovery may refer to: * Discovery (observation), observing or finding something unknown * Discovery (fiction), a character's learning something unknown * Discovery (law), a process in courts of law relating to evidence Discovery, The Discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irregular Satellites
In astronomy, an irregular moon, irregular satellite or irregular natural satellite is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit. They have been captured by their parent planet, unlike regular satellites, which formed in orbit around them. Irregular moons have a stable orbit, unlike temporary satellites which often have similarly irregular orbits but will eventually depart. The term does not refer to shape as Triton is a round moon, but is considered irregular due to its orbit. As of December 2022, 149 irregular moons are known, orbiting all four of the outer planets (Jupiter, Saturn, Uranus and Neptune). The largest of each planet are Himalia of Jupiter, Phoebe of Saturn, Sycorax of Uranus, and Triton of Neptune. It is currently thought that the irregular satellites were captured from heliocentric orbits near their current locations, shortly after the formation of their parent planet. An alternative theory, that they originated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moons Of Saturn
The moons of Saturn are numerous and diverse, ranging from tiny moonlets only tens of meters across to enormous Titan (moon), Titan, which is larger than the planet Mercury (planet), Mercury. Saturn has 83 natural satellite, moons with confirmed orbits that are not embedded in its Rings of Saturn, rings—of which only 13 have diameters greater than 50 kilometers—as well as dense rings that contain millions of embedded moonlets and innumerable smaller ring particles. Seven Saturnian moons are large enough to have collapsed into a relaxed, ellipsoidal shape, though only one or two of those, Titan and possibly Rhea (moon), Rhea, are currently in hydrostatic equilibrium. Particularly notable among Saturn's moons are Titan, the second-List of natural satellites, largest moon in the Solar System (after Jupiter's Ganymede (moon), Ganymede), with a Atmosphere of Titan#Composition, nitrogen-rich Earth-like Atmosphere of Titan, atmosphere and a landscape featuring dry river networks and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norse Group
The Norse group is a large group of retrograde irregular satellites of Saturn. Their semi-major axes range between 12 and 24 Gm, their inclinations between 136° and 175° and their eccentricities between 0.13 and 0.77. Unlike for the Inuit and Gallic groups, the orbital parameters are widely dispersed and group is likely to be composed from a number of subgroups with more homogenous orbital and physical parameters. For example, the satellites with inclinations around 174 degrees alone are thought to comprise at least two subgroups. Eight other moons form the Skathi subgroup. Their semi-major axes range between 15 and 20 Gm, their inclinations between 147° and 158°. Narvi forms a separate subgroup with Bestla. The International Astronomical Union (IAU) reserves names taken from Norse mythology (mostly giants) for these moons. The exception is Phoebe (Greek mythology), the largest, which was discovered long before the others. The discovery of 17 new moons in this group was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Odin
Odin (; from non, Óðinn, ) is a widely revered Æsir, god in Germanic paganism. Norse mythology, the source of most surviving information about him, associates him with wisdom, healing, death, royalty, the gallows, knowledge, war, battle, victory, sorcery, poetry, frenzy, and the Runes, runic alphabet, and depicts him as the husband of the goddess Frigg. In wider Germanic mythology and paganism, the god was also known in Old English as ', in Old Saxon as , in Old Dutch as ''Wuodan'', in Old Frisian as ''Wêda'', and in Old High German as , all ultimately stemming from the Proto-Germanic language, Proto-Germanic theonym *''Wōðanaz'', meaning 'lord of frenzy', or 'leader of the possessed'. Odin appears as a prominent god throughout the recorded history of Northern Europe, from the Roman occupation of regions of Germania (from BCE) through movement of peoples during the Migration Period (4th to 6th centuries CE) and the Viking Age (8th to 11th centuries CE). In the modern pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norse Mythology
Norse, Nordic, or Scandinavian mythology is the body of myths belonging to the North Germanic peoples, stemming from Old Norse religion and continuing after the Christianization of Scandinavia, and into the Nordic folklore of the modern period. The northernmost extension of Germanic mythology and stemming from Proto-Germanic folklore, Norse mythology consists of tales of various deities, beings, and heroes derived from numerous sources from both before and after the pagan period, including medieval manuscripts, archaeological representations, and folk tradition. The source texts mention numerous gods such as the thunder-god Thor, the raven-flanked god Odin, the goddess Freyja, and numerous other deities. Most of the surviving mythology centers on the plights of the gods and their interaction with several other beings, such as humanity and the jötnar, beings who may be friends, lovers, foes, or family members of the gods. The cosmos in Norse mythology consists of Nine Worl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jötunn
A (also jotun; in the normalised scholarly spelling of Old Norse, ; ; plural / ) or, in Old English, (plural ) is a type of supernatural being in Germanic mythology. In Norse mythology, they are often contrasted with gods (Æsir and Vanir) and other non-human figures, such as dwarfs and elves, although the groupings are not always mutually exclusive. The entities themselves are referred to by several other terms, including , (or ) and if male and or if female. The typically dwell across boundaries from the gods and humans in lands such as . The are frequently attested throughout the Old Norse record, with also featuring in the Old English epic poem ''Beowulf''. The usage of the terms is dynamic, with an overall trend that the beings become portrayed as less impressive and more negative as Christianity becomes more influential. Although the term "giant" is sometimes used to gloss the word "" and its apparent synonyms in some translations and academic texts, are not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bestla
Bestla (Old Norse: ) is a jötunn in Norse mythology, and the mother of the gods Odin, Vili and Vé (by way of Borr). She is also the sister of an unnamed man who assisted Odin, and the daughter (or granddaughter depending on the source) of the jötunn Bölþorn. Odin is frequently called "Bestla's son" in both skaldic verses and the Poetic Edda. Bestla is attested in the Poetic Edda, compiled in the 13th century from earlier traditional sources, the Prose Edda, written in the 13th century by Snorri Sturluson, and in the poetry of skalds. Scholars have commented on the obscurity of the figure's name and have proposed various theories to explain the role and origin of the giantess. Name The meaning of the Old Norse name ''Bestla'' remains uncertain. Scholars have proposed potential meanings such as 'wife', or ' bark, bast'. It might stem from ''*Bastilōn'' (perhaps a yew goddess, originally a 'bast-donor'), or from ''*Banstillōn'' (via an intermediate form ''*Böstla''), relat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Curve
In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequency interval or band. Light curves can be periodic, as in the case of eclipsing binaries, Cepheid variables, other periodic variables, and transiting extrasolar planets, or aperiodic, like the light curve of a nova, a cataclysmic variable star, a supernova or a microlensing event or binary as observed during occultation events. The study of the light curve, together with other observations, can yield considerable information about the physical process that produces it or constrain the physical theories about it. Variable stars Graphs of the apparent magnitude of a variable star over time are commonly used to visualise and analyse their behaviour. Although the categorisation of variable star types is increasingly done from their s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contact Binary
In astronomy, a contact binary is a binary star system whose component stars are so close that they touch each other or have merged to share their gaseous envelopes. A binary system whose stars share an envelope may also be called an overcontact binary. The term "contact binary" was introduced by astronomer Gerard Kuiper in 1941. Almost all known contact binary systems are eclipsing binaries; eclipsing contact binaries are known as W Ursae Majoris variables, after their type star, W Ursae Majoris. In a contact binary, both stars have filled their Roche lobes, allowing the more massive primary component to transfer both mass and luminosity to the secondary member. As a result, the components in a contact binary often have similar effective temperatures and luminosities, regardless of their respective masses. The rate of energy transfer between the components is dependent on their mass ratio and luminosity ratio. In cases where the stars are in geometric contact but the thermal c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
