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39 (number)
39 (thirty-nine) is the natural number following 38 and preceding 40. In mathematics *39 is the sum of five consecutive primes (3 + 5 + 7 + 11 + 13) and also is the product of the first and the last of those consecutive primes. Among small semiprimes only three other integers (10, 155, and 371) share this attribute. 39 also is the sum of the first three powers of 3 (3 + 3 + 3). Given 39, the Mertens function returns 0. *39 is the smallest natural number which has three partitions into three parts which all give the same product when multiplied: , , . *39 is the 12th distinct semiprime and the 4th in the family. It is the last member of the third distinct semiprime pair (38,39). *39 has an aliquot sum of 17 which is a prime. 39 is the 4th member of the 17-aliquot tree. It is a perfect totient number. *The thirteenth Perrin number is 39, which comes after 17, 22, 29 (it is the sum of the first two mentioned). *Since the greatest prime factor of 392 + 1 = 1522 is 761, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Number
In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country"). Numbers used for counting are called ''cardinal numbers'', and numbers used for ordering are called ''ordinal numbers''. Natural numbers are sometimes used as labels, known as '' nominal numbers'', having none of the properties of numbers in a mathematical sense (e.g. sports jersey numbers). Some definitions, including the standard ISO 80000-2, begin the natural numbers with , corresponding to the non-negative integers , whereas others start with , corresponding to the positive integers Texts that exclude zero from the natural numbers sometimes refer to the natural numbers together with zero as the whole numbers, while in other writings, that term is used instead for the integers (including negative integers). The natural numbers form a set. Many other number sets are built by succ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messier Object
The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his ''Catalogue des Nébuleuses et des Amas d'Étoiles'' (''Catalogue of Nebulae and Star Clusters''). Because Messier was only interested in finding comets, he created a list of those non-comet objects that frustrated his hunt for them. The compilation of this list, in collaboration with his assistant Pierre Méchain, is known as ''the Messier catalogue''. This catalogue of objects is one of the most famous lists of astronomical objects, and many Messier objects are still referenced by their Messier numbers. The catalogue includes most of the astronomical deep-sky objects that can easily be observed from Earth's Northern Hemisphere; many Messier objects are popular targets for amateur astronomers. A preliminary version first appeared in 1774 in the ''Memoirs'' of the French Academy of Sciences for the year 1771. The first version of Messier's catalogue conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sanhedrin
The Sanhedrin (Hebrew and Aramaic: סַנְהֶדְרִין; Greek: , ''synedrion'', 'sitting together,' hence ' assembly' or 'council') was an assembly of either 23 or 71 elders (known as "rabbis" after the destruction of the Second Temple), appointed to sit as a tribunal in every city in the ancient Land of Israel. There were two classes of Rabbinite Jewish courts which were called Sanhedrin, the Great Sanhedrin and the Lesser Sanhedrin. A lesser Sanhedrin of 23 judges was appointed to sit as a tribunal in each city, but there was only supposed to be one Great Sanhedrin of 71 judges, which among other roles acted as the Supreme Court, taking appeals from cases which were decided by lesser courts. In general usage, ''the Sanhedrin'' without qualifier normally refers to the Great Sanhedrin, which was presided over by the '' Nasi'', who functioned as its head or representing president, and was a member of the court; the '' Av Beit Din'' or the chief of the court, who was secon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torah
The Torah (; hbo, ''Tōrā'', "Instruction", "Teaching" or "Law") is the compilation of the first five books of the Hebrew Bible, namely the books of Genesis, Exodus, Leviticus, Numbers and Deuteronomy. In that sense, Torah means the same as Pentateuch or the Five Books of Moses. It is also known in the Jewish tradition as the Written Torah (, ). If meant for liturgic purposes, it takes the form of a Torah scroll ('' Sefer Torah''). If in bound book form, it is called ''Chumash'', and is usually printed with the rabbinic commentaries (). At times, however, the word ''Torah'' can also be used as a synonym for the whole of the Hebrew Bible or Tanakh, in which sense it includes not only the first five, but all 24 books of the Hebrew Bible. Finally, Torah can even mean the totality of Jewish teaching, culture, and practice, whether derived from biblical texts or later rabbinic writings. The latter is often known as the Oral Torah. Representing the core of the Jewish spi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halakha
''Halakha'' (; he, הֲלָכָה, ), also transliterated as ''halacha'', ''halakhah'', and ''halocho'' ( ), is the collective body of Jewish religious laws which is derived from the written and Oral Torah. Halakha is based on biblical commandments (''mitzvot''), subsequent Talmudic and rabbinic laws, and the customs and traditions which were compiled in the many books such as the ''Shulchan Aruch''. ''Halakha'' is often translated as "Jewish law", although a more literal translation of it might be "the way to behave" or "the way of walking". The word is derived from the root which means "to behave" (also "to go" or "to walk"). ''Halakha'' not only guides religious practices and beliefs, it also guides numerous aspects of day-to-day life. Historically, in the Jewish diaspora, ''halakha'' served many Jewish communities as an enforceable avenue of law – both civil and religious, since no differentiation of them exists in classical Judaism. Since the Jewish Enlightenment (''Haska ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
39 Melachot
The 39 Melakhot ( he, ל״ט אבות מלאכה, '' lamed-tet avot melakhah'', "39 categories of work") are thirty-nine categories of activity which Jewish law identifies as prohibited by biblical law on Shabbat. Many of these activities are also prohibited on the Jewish holidays listed in the Torah, although there are significant exceptions that permit carrying and preparing food under specific circumstances on holidays (except Yom Kippur). In addition to the 39 melakhot, certain other activities are forbidden on Shabbat due to rabbinic law. There are often disagreements between Orthodox Jews and Conservative Jews or other non-Orthodox Jews as to the practical observance of Shabbat. It is of note that the (strict) observance of Shabbat is often seen as a benchmark for orthodoxy and indeed has legal bearing on the way a Jew is seen by an Orthodox religious court regarding their affiliation to Judaism. The commandment The commandment to keep Shabbat as a day of rest is repeated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda (constellation)
Andromeda is one of the 48 constellations listed by the 2nd-century Greco-Roman astronomer Ptolemy, and one of the 88 modern constellations. Located in the northern celestial hemisphere, it is named for Andromeda, daughter of Cassiopeia, in the Greek myth, who was chained to a rock to be eaten by the sea monster Cetus. Andromeda is most prominent during autumn evenings in the Northern Hemisphere, along with several other constellations named for characters in the Perseus myth. Because of its northern declination, Andromeda is visible only north of 40° south latitude; for observers farther south, it lies below the horizon. It is one of the largest constellations, with an area of 722 square degrees. This is over 1,400 times the size of the full moon, 55% of the size of the largest constellation, Hydra, and over 10 times the size of the smallest constellation, Crux. Its brightest star, Alpha Andromedae, is a binary star that has also been counted as a part of Pegasus, whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiral Galaxy
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''Alt URL pp. 124–151) and, as such, form part of the . Most spiral galaxies consist of a flat, rotating disk containing s, gas and dust, and a central concentration of stars known as the |
NGC 39
NGC 39 (also known as UGC 114, MCG 5-1-52, ZWG 499.76 or PGC 852) is an unbarred spiral galaxy in the constellation Andromeda. It was discovered in 1790. References External links * * NGC 39seds.org {{DEFAULTSORT:NGC 0039 Unbarred spiral galaxies Andromeda (constellation) 0039 00852 00114 17901102 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New General Catalogue
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the ''Index Catalogues'' (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use. The NGC expanded and consolidated the cataloguing work of William and Caroline Herschel, and John Herschel's '' General Catalogue of Nebulae and Clusters of Stars''. Objects south of the celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop. The NGC contained multiple errors, but attempts to eliminate them were made by the ''Revised New General Catalogue'' (RNGC) by Jack W. Su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cygnus (constellation)
Cygnus is a northern constellation on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. Cygnus is one of the most recognizable constellations of the northern summer and autumn, and it features a prominent asterism known as the Northern Cross (in contrast to the Southern Cross). Cygnus was among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. Cygnus contains Deneb (ذنب, translit. ''ḏanab,'' tail)one of the brightest stars in the night sky and the most distant first-magnitude staras its "tail star" and one corner of the Summer Triangle. It also has some notable X-ray sources and the giant stellar association of Cygnus OB2. Cygnus is also known as the Northern Cross. One of the stars of this association, NML Cygni, is one of the largest stars currently known. The constellation is also home to Cygnus X-1, a distant X-ray binary containing a supergiant and unsee ... [...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] |
