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4959 Niinoama
4959 Niinoama ( ''prov. designation'': ) is a dark background asteroid from the outer regions of the asteroid belt. It was discovered by Japanese astronomers Akira Natori and Takeshi Urata at JCPM Yakiimo Station on 15 August 1991. The presumed carbonaceous C-type asteroid has a rotation period of 4.7 hours and measures approximately in diameter. It was named after Taira no Tokiko (1126–1185) of the Imperial House of Japan during the Heian period. Orbit and classification ''Niinoama'' is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. It orbits the Sun in the outer main-belt at a distance of 3.1–3.2 AU once every 5 years and 7 months (2,044 days). Its orbit has an eccentricity of 0.01 and an inclination of 9 ° with respect to the ecliptic. A first precovery was taken at Palomar Observatory in May 1950, extending the body's observation arc by more than 41 years pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightcurve
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heian Period
The is the last division of classical Japanese history, running from 794 to 1185. It followed the Nara period, beginning when the 50th emperor, Emperor Kanmu, moved the capital of Japan to Heian-kyō (modern Kyoto). means "peace" in Japanese. It is a period in Japanese history when the Chinese influences were in decline and the national culture matured. The Heian period is also considered the peak of the Japanese imperial court and noted for its art, especially poetry and literature. Two types of Japanese script emerged, including katakana, a phonetic script which was abbreviated into hiragana, a cursive alphabet with a unique writing method distinctive to Japan. This gave rise to Japan's famous vernacular literature, with many of its texts written by court women who were not as educated in Chinese compared to their male counterparts. Although the Imperial House of Japan had power on the surface, the real power was in the hands of the Fujiwara clan, a powerful aristocr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Tale Of The Heike
is an epic account compiled prior to 1330 of the struggle between the Taira clan and Minamoto clan for control of Japan at the end of the 12th century in the Genpei War (1180–1185). Heike () refers to the Taira (), ''hei'' being the ''on'yomi'' reading of the first ''kanji'' and "ke" () means family. Note that in the title of the Genpei War, "hei" is in this combination read as "pei" and the "gen" () is the first kanji used in the Minamoto (also known as "Genji" which is also pronounced using ''on'yomi'', for example as in '' The Tale of Genji'') clan's name. It has been translated into English at least five times, the first by Arthur Lindsay Sadler in 1918–1921. A complete translation in nearly 800 pages by Hiroshi Kitagawa & Bruce T. Tsuchida was published in 1975. Also translated by Helen McCullough in 1988. An abridged translation by Burton Watson was published in 2006. In 2012, Royall Tyler completed his translation, which seeks to be mindful of the performance s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emperor Antoku
was the 81st emperor of Japan, according to the traditional order of succession. His reign spanned the years from 1180 through 1185. During this time, the Imperial family was involved in a bitter struggle between warring clans. Minamoto no Yoritomo with his cousin Minamoto no Yoshinaka, led a force from the Minamoto clan against the Taira, who controlled the emperor. During the climactic sea Battle of Dan-no-ura in April 1185, Antoku's grandmother Taira no Tokiko took him and plunged with him into the water in the Shimonoseki Straits, drowning the child emperor rather than allowing him to be captured by the opposing forces. The conflict between the clans led to numerous legends and tales. The story of Emperor Antoku and his mother's family became the subject of the Kamakura period epic poem ''The Tale of the Heike'' (Heike is an alternative reading of the Japanese characters for "House of the Taira"). Antoku's tomb is said to be located in a number of places around western Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taira No Kiyomori
was a military leader and ''kugyō'' of the late Heian period of Japan. He established the first samurai-dominated administrative government in the history of Japan. Early life Kiyomori was born in Heian-kyō, Japan, in 1118 as the first son of Taira no Tadamori, who was the head of the Taira clan. It has been speculated that Kiyomori was actually an illegitimate son of Emperor Shirakawa. His mother, Gion no Nyogo, was a palace servant according to '' The Tale of the Heike''. Family * Father: Taira no Tadamori * Mother: Gion no Nyogo (d. 1147) *Concubines and regents: **Wife: N/A *** Taira no Shigemori *** Taira no Munemori *** Taira no Tomomori *** Taira no Tokuko *** Taira no Shigehira Career After the death of his father in 1159, Kiyomori assumed control of the Taira clan and ambitiously entered the political realm in which he had previously only held a minor post. Before that though, in 1156, he and Minamoto no Yoshitomo, head of the Minamoto clan, suppressed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minor Planet
According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor planet'', but that year's meeting reclassified minor planets and comets into dwarf planets and small Solar System bodies (SSSBs).Press release, IAU 2006 General Assembly: Result of the IAU Resolution votes International Astronomical Union, August 24, 2006. Accessed May 5, 2008. Minor planets include asteroids ( |
Observation Arc
In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly used in the discovery and tracking of asteroids and comets. Arc length has the greatest influence on the accuracy of an orbit. The number and spacing of intermediate observations has a lesser effect. Short arcs A very short arc leaves a high uncertainty parameter. The object might be in one of many different orbits, at many distances from Earth. In some cases, the initial arc was too short to determine if the object was in orbit around the Earth, or orbiting out in the asteroid belt. With a 1-day observation arc, was thought to be a trans-Neptunian dwarf planet, but is now known to be a 1 km main-belt asteroid. With an observation arc of 3 days, was thought to be a Mars-crossing asteroid that could be a threat to Earth, but was l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palomar Observatory
Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observatory is granted to Caltech and its research partners, which include the Jet Propulsion Laboratory (JPL), Yale University, and the National Optical Observatories of China. The observatory operates several telescopes, including the Hale Telescope, the Samuel Oschin Telescope (dedicated to the Zwicky Transient Facility, ZTF), the Palomar Telescope, and the Gattini-IR telescope. Decommissioned instruments include the Palomar Testbed Interferometer and the first telescopes at the observatory, an Schmidt camera from 1936. History Hale's vision for large telescopes and Palomar Observatory Astronomer George Ellery Hale, whose vision created the Palomar Observatory, built the world's largest telescope four times in succession. He published ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precovery
In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of an object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This happens most often with minor planets, but sometimes a comet, a dwarf planet, a natural satellite, or a star is found in old archived images; even exoplanet precovery observations have been obtained. "Precovery" refers to a pre-discovery image; "recovery" refers to imaging of a body which was lost to our view (as behind the Sun), but is now visible again ''(also see lost minor planet and lost comet)''. Orbit determination requires measuring an object's position on multiple occasions. The longer the interval between observations, the more accurately the orbit can be calculated; however, for a newly discovered object, only a few days' or weeks' worth of measured positions may be available, sufficient only for a preliminary (imprecise) orbit calcul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecliptic
The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the background of stars. The ecliptic is an important reference plane and is the basis of the ecliptic coordinate system. Sun's apparent motion The ecliptic is the apparent path of the Sun throughout the course of a year. Because Earth takes one year to orbit the Sun, the apparent position of the Sun takes one year to make a complete circuit of the ecliptic. With slightly more than 365 days in one year, the Sun moves a little less than 1° eastward every day. This small difference in the Sun's position against the stars causes any particular spot on Earth's surface to catch up with (and stand directly north or south of) the Sun about four minutes later each day than it would if Earth did not orbit; a day on Earth is therefore 24 hours ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planet's equator. For pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Eccentricity
In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit (or capture orbit), and greater than 1 is a hyperbola. The term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the Galaxy. Definition In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit. The eccentricity of this Kepler orbit is a non-negative number that defines its shape. The eccentricity may take the following values: * circular orbit: ''e'' = 0 * elliptic orbit: 0 < ''e'' < 1 * [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
