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169 (number)
169 (one hundred ndsixty-nine) is the natural number following 168 and preceding 170. In mathematics 169 is an odd number, a composite number, and a deficient number. 169 is a square number: 13 × 13 = 169, and if each number is reversed the equation is still true: 31 × 31 = 961. 144 shares this property: 12 × 12 = 144, 21 × 21 = 441. 169 is one of the few squares to also be a centered hexagonal number. Like all odd squares, it is a centered octagonal number. 169 is an odd-indexed Pell number, thus it is also a Markov number, appearing in the solutions (2, 169, 985), (2, 29, 169), (29, 169, 14701), etc. 169 is the sum of seven consecutive primes: 13 + 17 + 19 + 23 + 29 + 31 + 37. 169 is a difference in consecutive cubes, equaling 8^3-7^3. In astronomy * 169 Zelia is a bright main belt asteroid * Gliese 169 is an orange, main sequence (K7 V) star in the constellation Taurus * QSO B0307+169 is a quasar in the constellation Aries * Sayh al Uhaymir 169 is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
168 (number)
168 (one hundred [and] sixty-eight) is the natural number following 167 (number), 167 and preceding 169 (number), 169. In mathematics 168 is an even number, a composite number, an abundant number, and an idoneal number. There are 168 prime number, primes less than 1000 (number), 1000. 168 is the product of the first two perfect numbers. 168 is the order of the group PSL(2,7), the second smallest Nonabelian group, nonabelian simple group. From Hurwitz's automorphisms theorem, 168 is the maximum possible number of automorphisms of a genus 3 Riemann surface, this maximum being achieved by the Klein quartic, whose symmetry group is PSL(2,7). The Fano plane has 168 symmetries. 168 is the largest known n such that 2^n does not contain all decimal digits. In astronomy * 168P/Hergenrother is a periodic comet in the Solar System * 168 Sibylla is a dark Asteroid belt, Main belt asteroid In the military * was an Imperial Japanese Navy during World War II * is a United States Navy flee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
29 (number)
29 (twenty-nine) is the natural number following 28 and preceding 30. Mathematics * 29 is the tenth prime number, and the fourth primorial prime. * 29 forms a twin prime pair with thirty-one, which is also a primorial prime. Twenty-nine is also the sixth Sophie Germain prime. * 29 is the sum of three consecutive squares, 22 + 32 + 42. * 29 is a Lucas prime, a Pell prime, and a tetranacci number. * 29 is an Eisenstein prime with no imaginary part and real part of the form 3n − 1. 29 is also the 10th supersingular prime. * None of the first 29 natural numbers have more than two different prime factors. This is the longest such consecutive sequence. * 29 is a Markov number, appearing in the solutions to ''x'' + ''y'' + ''z'' = 3''xyz'': , , , , etc. * 29 is a Perrin number, preceded in the sequence by 12, 17, 22. * 29 is the smallest positive whole number that cannot be made from the numbers , using each exactly once and using only addition, subtraction, multiplication, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sayh Al Uhaymir 169
Sayh al Uhaymir 169 (SaU 169) is a 206 grams lunar meteorite found in the Sayh al Uhaymir region of the Sultanate of Oman in January 2002. This stone is an impact-melt breccia with exceedingly high concentrations of thorium and other incompatible elements; phosphorus, rare-earth elements, and the three most important naturally occurring radioactive elements, potassium, thorium, and uranium have been segregated in the liquid phase when the lunar minerals crystallized. The impact that eventually sent this stone to the Earth is dated at 3.9 billion years and could be the Imbrium impact. It collided with the Earth less than 9,700 years ago. It is complete, a light gray-greenish rounded stone, dimensions and mass , found on January 16, 2002, in the central desert of Oman at 20° 34.391' N and 57° 19.400' E. According to geologist Edwin Gnos and coworkers, the meteorite's origin can be pinpointed to the vicinity of the Lalande impact crater; isotopic analysis shows a complex his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aries (constellation)
Aries is one of the constellations of the zodiac. It is located in the Northern celestial hemisphere between Pisces to the west and Taurus to the east. The name Aries is Latin for ram. Its old astronomical symbol is (♈︎). It is one of the 48 constellations described by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. It is a mid-sized constellation ranking 39th in overall size, with an area of 441 square degrees (1.1% of the celestial sphere). Aries has represented a ram since late Babylonian times. Before that, the stars of Aries formed a farmhand. Different cultures have incorporated the stars of Aries into different constellations including twin inspectors in China and a porpoise in the Marshall Islands. Aries is a relatively dim constellation, possessing only four bright stars: Hamal (Alpha Arietis, second magnitude), Sheratan (Beta Arietis, third magnitude), Mesarthim (Gamma Arietis, fourth magnitude), and 41 Arietis (also fourt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasar
A quasar is an extremely luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous accretion disc. Gas in the disc falling towards the black hole heats up because of friction and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosities thousands of times greater than that of a galaxy such as the Milky Way. Usually, quasars are categorized as a subclass of the more general category of AGN. The redshifts of quasars are of cosmological origin. The term originated as a contraction of "quasi-stellar '' tar-like' radio source"—because quasars were first identified during the 1950s as sources of radio-wave emission of unknown physical origin—and when identi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QSO B0307+169
3C 79 is a Seyfert Galaxy located in the constellation Aries. The extended emission-line region (EELR) is almost certainly photoionized by the hidden quasar. References External links www.jb.man.ac.uk/atlas/(J. P. Leahy) * Wikiskimageof PGC 1524618 079 79 may refer to: * 79 (number) * one of the years 79 BC, AD 79, 1979, 2079 * ''79 A.D.'', a 1962 historical epic film * Eruption of Mount Vesuvius in 79, a catastrophic volcanic eruption in Italy See also * * List of highways numbered {{Num ... Radio galaxies 3C 79 Aries (constellation) Seyfert galaxies {{galaxy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taurus (constellation)
Taurus (Latin for "the Bull") is one of the constellations of the zodiac and is located in the northern celestial hemisphere. Taurus is a large and prominent constellation in the Northern Hemisphere's winter sky. It is one of the oldest constellations, dating back to the Early Bronze Age at least, when it marked the location of the Sun during the spring equinox. Its importance to the agricultural calendar influenced various bull figures in the mythologies of Ancient Sumer, Akkad, Assyria, Babylon, Egypt, Greece, and Rome. Its old astronomical symbol is (♉︎), which resembles a bull's head. A number of features exist that are of interest to astronomers. Taurus hosts two of the nearest open clusters to Earth, the Pleiades and the Hyades, both of which are visible to the naked eye. At first magnitude, the red giant Aldebaran is the brightest star in the constellation. In the northeast part of Taurus is Messier 1, more commonly known as the Crab Nebula, a supernova remn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellations likely go back to prehistory. People used them to relate stories of their beliefs, experiences, creation, or mythology. Different cultures and countries adopted their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. The 48 traditional Western constellations are Greek. They are given in Aratus' work ''Phenomena'' and Ptolemy's '' Almagest'', though their origin probably predates these works by several centuries. Constellations in the far southern sky were ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orange (colour)
Orange is the colour between yellow and red on the spectrum of visible light. Human eyes perceive orange when observing light with a dominant wavelength between roughly 585 and 620 nanometres. In traditional colour theory, it is a secondary colour of pigments, produced by mixing yellow and red. In the RGB colour model, it is a tertiary colour. It is named after the fruit of the same name. The orange colour of many fruits and vegetables, such as carrots, pumpkins, sweet potatoes, and oranges, comes from carotenes, a type of photosynthetic pigment. These pigments convert the light energy that the plants absorb from the Sun into chemical energy for the plants' growth. Similarly, the hues of autumn leaves are from the same pigment after chlorophyll is removed. In Europe and America, surveys show that orange is the colour most associated with amusement, the unconventional, extroversion, warmth, fire, energy, activity, danger, taste and aroma, the autumn and Allh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gliese 169
Gliese may refer to: * Rochus Gliese (1891—1978), a German actor, director, production designer, and art director * Wilhelm Gliese (1915–1993), a German astronomer, best known for the Gliese Catalogue of Nearby Stars * Gliese Catalogue of Nearby Stars, a modern star catalog of stars located within 25 parsecs of the Earth * Gliese 163, a red dwarf located 49 light years from the Sun * Gliese 229, a binary system composed of a red dwarf and a brown dwarf about 19 light years away in the constellation Lepus. * Gliese 581, a red dwarf orbited by several extra-solar planets, at least ** Gliese 581d, a planet in the star's habitable zone * Gliese 667, a triple star system in the constellation of Scorpius containing exoplanet GJ 667 Cc in one of the stars' habitable zone * Gliese 682, a red dwarf in the constellation of Scorpius with two candidate planets, one of which is in the star's habitable zone * Gliese 710, a star projected to pass through the Oort Cloud in 1.35 million years ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. Of the roughly one million known asteroids the greatest number are located between the orbits of Mars and Jupiter, approximately 2 to 4 AU from the Sun, in the main asteroid belt. Asteroids are generally classified to be of three types: C-type, M-type, and S-type. These were named after and are generally identified with carbonaceous, metallic, and silicaceous compositions, respectively. The size of asteroids varies greatly; the largest, Ceres, is almost across and qualifies as a dwarf planet. The total mass of all the asteroids combined is only 3% that of Earth's Moon. The majority of main belt asteroids follow slightly elliptical, stable orbits, revolving in the same direction as the Earth and taking from three to six years to co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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