1.
Messier catalog
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The Messier objects are a set of over 100 astronomical objects first listed by French astronomer Charles Messier in 1771. The number of objects in the lists he published reached 103, a similar list had been published in 1654 by Giovanni Hodierna, but attracted attention only recently and was probably not known to Messier. The first edition covered 45 objects numbered M1 to M45, the first such addition came from Nicolas Camille Flammarion in 1921, who added Messier 104 after finding a note Messier made in a copy of the 1781 edition of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, M102 was observed by Méchain, who communicated his notes to Messier. Méchain later concluded that this object was simply a re-observation of M101, though sources suggest that the object Méchain observed was the galaxy NGC5866. Messiers final catalogue was included in the Connaissance des Temps for 1784 and these objects are still known by their Messier number from this list. Messier lived and did his work at the Hôtel de Cluny. The list he compiled contains only objects found in the sky area he could observe and he did not observe or list objects visible only from farther south, such as the Large and Small Magellanic Clouds. A summary of the astrophysics of each Messier object can be found in the Concise Catalog of Deep-sky Objects, in early spring, astronomers sometimes gather for Messier marathons, when all of the objects can be viewed over a single night
2.
Legion of Honour
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The Legion of Honour, full name National Order of the Legion of Honour, is the highest French order of merit for military and civil merits, established 1802 by Napoléon Bonaparte. The order is divided into five degrees of increasing distinction, Chevalier, Officier, Commandeur, Grand Officier and Grand-Croix. The orders motto is Honneur et Patrie and its seat is the Palais de la Légion dHonneur next to the Musée dOrsay, in the French Revolution, all French orders of chivalry were abolished, and replaced with Weapons of Honour. The Légion however did use the organization of old French orders of chivalry, the badges of the legion also bear a resemblance to the Ordre de Saint-Louis, which also used a red ribbon. Napoleon originally created this to ensure political loyalty, the organization would be used as a facade to give political favours, gifts, and concessions. The Légion was loosely patterned after a Roman legion, with legionaries, officers, commanders, regional cohorts, the highest rank was not a grand cross but a Grand Aigle, a rank that wore all the insignia common to grand crosses. The members were paid, the highest of them extremely generously,5,000 francs to an officier,2,000 francs to a commandeur,1,000 francs to an officier,250 francs to a légionnaire. Napoleon famously declared, You call these baubles, well, it is with baubles that men are led, do you think that you would be able to make men fight by reasoning. That is good only for the scholar in his study, the soldier needs glory, distinctions, rewards. This has been quoted as It is with such baubles that men are led. The order was the first modern order of merit, under the monarchy, such orders were often limited to Roman Catholics, and all knights had to be noblemen. The military decorations were the perks of the officers, the Légion, however, was open to men of all ranks and professions—only merit or bravery counted. The new legionnaire had to be sworn in the Légion and it is noteworthy that all previous orders were crosses or shared a clear Christian background, whereas the Légion is a secular institution. The jewel of the Légion has five arms, in a decree issued on the 10 Pluviôse XIII, a grand decoration was instituted. This decoration, a cross on a sash and a silver star with an eagle, symbol of the Napoleonic Empire, became known as the Grand Aigle. After Napoleon crowned himself Emperor of the French in 1804 and established the Napoleonic nobility in 1808, the title was made hereditary after three generations of grantees. Napoleon had dispensed 15 golden collars of the legion among his family and this collar was abolished in 1815. The Légion dhonneur was prominent and visible in the French Empire, the Emperor always wore it and the fashion of the time allowed for decorations to be worn most of the time
3.
Astronomy
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Astronomy is a natural science that studies celestial objects and phenomena. It applies mathematics, physics, and chemistry, in an effort to explain the origin of those objects and phenomena and their evolution. Objects of interest include planets, moons, stars, galaxies, and comets, while the phenomena include supernovae explosions, gamma ray bursts, more generally, all astronomical phenomena that originate outside Earths atmosphere are within the purview of astronomy. A related but distinct subject, physical cosmology, is concerned with the study of the Universe as a whole, Astronomy is the oldest of the natural sciences. The early civilizations in recorded history, such as the Babylonians, Greeks, Indians, Egyptians, Nubians, Iranians, Chinese, during the 20th century, the field of professional astronomy split into observational and theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects, theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. The two fields complement each other, with theoretical astronomy seeking to explain the results and observations being used to confirm theoretical results. Astronomy is one of the few sciences where amateurs can play an active role, especially in the discovery. Amateur astronomers have made and contributed to many important astronomical discoveries, Astronomy means law of the stars. Astronomy should not be confused with astrology, the system which claims that human affairs are correlated with the positions of celestial objects. Although the two share a common origin, they are now entirely distinct. Generally, either the term astronomy or astrophysics may be used to refer to this subject, however, since most modern astronomical research deals with subjects related to physics, modern astronomy could actually be called astrophysics. Few fields, such as astrometry, are purely astronomy rather than also astrophysics, some titles of the leading scientific journals in this field includeThe Astronomical Journal, The Astrophysical Journal and Astronomy and Astrophysics. In early times, astronomy only comprised the observation and predictions of the motions of objects visible to the naked eye, in some locations, early cultures assembled massive artifacts that possibly had some astronomical purpose. Before tools such as the telescope were invented, early study of the stars was conducted using the naked eye, most of early astronomy actually consisted of mapping the positions of the stars and planets, a science now referred to as astrometry. From these observations, early ideas about the motions of the planets were formed, and the nature of the Sun, Moon, the Earth was believed to be the center of the Universe with the Sun, the Moon and the stars rotating around it. This is known as the model of the Universe, or the Ptolemaic system. The Babylonians discovered that lunar eclipses recurred in a cycle known as a saros
4.
Nebula
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A nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases. Originally, nebula was a name for any diffuse astronomical object, the Andromeda Galaxy, for instance, was once referred to as the Andromeda Nebula before the true nature of galaxies was confirmed in the early 20th century by Vesto Slipher, Edwin Hubble and others. Most nebulae are of vast size, even millions of years in diameter. The Orion Nebula, the brightest nebula in the sky that occupies a region twice the diameter of the full Moon, can be viewed with the naked eye but was missed by early astronomers. Many nebulae are visible due to their fluorescence caused by the hot stars, while others are so diffuse they can only be detected with long exposures. Some nebulae are variably illuminated by T Tauri variable stars, Nebulae are often star-forming regions, such as in the Pillars of Creation in the Eagle Nebula. In these regions the formations of gas, dust, and other materials together to form denser regions, which attract further matter. The remaining material is believed to form planets and other planetary system objects. Around 150 AD, Claudius Ptolemaeus recorded, in books VII–VIII of his Almagest and he also noted a region of nebulosity between the constellations Ursa Major and Leo that was not associated with any star. The first true nebula, as distinct from a cluster, was mentioned by the Persian astronomer Abd al-Rahman al-Sufi. He noted a little cloud where the Andromeda Galaxy is located and he also cataloged the Omicron Velorum star cluster as a nebulous star and other nebulous objects, such as Brocchis Cluster. The supernova that created the Crab Nebula, the SN1054, was observed by Arabic, in 1610, Nicolas-Claude Fabri de Peiresc discovered the Orion Nebula using a telescope. This nebula was observed by Johann Baptist Cysat in 1618. However, the first detailed study of the Orion Nebula was not performed until 1659 by Christiaan Huygens, in 1715, Edmund Halley published a list of six nebulae. This number steadily increased during the century, with Jean-Philippe de Cheseaux compiling a list of 20 in 1746, from 1751 to 1753, Nicolas Louis de Lacaille cataloged 42 nebulae from the Cape of Good Hope, most of which were previously unknown. Charles Messier then compiled a catalog of 103 nebulae by 1781, his interest was detecting comets, the number of nebulae was then greatly expanded by the efforts of William Herschel and his sister Caroline Herschel. Their Catalogue of One Thousand New Nebulae and Clusters of Stars was published in 1786, a second catalog of a thousand was published in 1789 and the third and final catalog of 510 appeared in 1802. During much of their work, William Herschel believed that these nebulae were merely unresolved clusters of stars, in 1790, however, he discovered a star surrounded by nebulosity and concluded that this was a true nebulosity, rather than a more distant cluster
5.
Star cluster
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Star clusters or star clouds are groups of stars. Star clusters visible to the eye include Pleiades, Hyades. Globular clusters, or GC, are roughly spherical groupings of from 10,000 to several million stars packed into regions of from 10 to 30 light years across. They commonly consist of very old Population II stars—just a few hundred years younger than the universe itself—which are mostly yellow and red. Such stars predominate within clusters because hotter and more stars have exploded as supernovae. Yet a few rare blue stars exist in globulars, thought to be formed by mergers in their dense inner regions. In our galaxy, globular clusters are distributed roughly spherically in the halo, around the galactic centre. Super star clusters, such as Westerlund 1 in the Milky Way, may be the precursors of globular clusters. Our galaxy has about 150 globular clusters, some of which may have captured from small galaxies disrupted by the Milky Way. Some galaxies are much richer in globulars, the giant elliptical galaxy M87 contains over a thousand. A few of the brightest globular clusters are visible to the eye, with the brightest, Omega Centauri, having been known since antiquity. The best known globular cluster in the northern hemisphere is M13, in 2005, astronomers discovered a completely new type of star cluster in the Andromeda Galaxy, which is, in several ways, very similar to globular clusters. Currently, there are not any intermediate clusters discovered in the Milky Way, the three discovered in Andromeda Galaxy are M31WFS C1 M31WFS C2, and M31WFS C3. These new-found star clusters contain hundreds of thousands of stars, a number of stars that can be found in globular clusters. The clusters also share characteristics with globular clusters, e. g. the stellar populations. What distinguishes them from the clusters is that they are much larger – several hundred light-years across –. The distances between the stars are, therefore, much greater within the newly discovered extended clusters, parametrically, these clusters lie somewhere between a globular cluster and a dwarf spheroidal galaxy. How these clusters are formed is not yet known, but their formation might well be related to that of globular clusters, why M31 has such clusters, while the Milky Way has not, is not yet known
6.
Messier object
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The Messier objects are a set of over 100 astronomical objects first listed by French astronomer Charles Messier in 1771. The number of objects in the lists he published reached 103, a similar list had been published in 1654 by Giovanni Hodierna, but attracted attention only recently and was probably not known to Messier. The first edition covered 45 objects numbered M1 to M45, the first such addition came from Nicolas Camille Flammarion in 1921, who added Messier 104 after finding a note Messier made in a copy of the 1781 edition of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, M102 was observed by Méchain, who communicated his notes to Messier. Méchain later concluded that this object was simply a re-observation of M101, though sources suggest that the object Méchain observed was the galaxy NGC5866. Messiers final catalogue was included in the Connaissance des Temps for 1784 and these objects are still known by their Messier number from this list. Messier lived and did his work at the Hôtel de Cluny. The list he compiled contains only objects found in the sky area he could observe and he did not observe or list objects visible only from farther south, such as the Large and Small Magellanic Clouds. A summary of the astrophysics of each Messier object can be found in the Concise Catalog of Deep-sky Objects, in early spring, astronomers sometimes gather for Messier marathons, when all of the objects can be viewed over a single night
7.
Comet
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A comet is an icy small Solar System body that, when passing close to the Sun, warms and begins to evolve gasses, a process called outgassing. This produces an atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred metres to tens of kilometres across and are composed of collections of ice, dust. The coma may be up to 15 times the Earths diameter, if sufficiently bright, a comet may be seen from the Earth without the aid of a telescope and may subtend an arc of 30° across the sky. Comets have been observed and recorded since ancient times by many cultures, Comets usually have highly eccentric elliptical orbits, and they have a wide range of orbital periods, ranging from several years to potentially several millions of years. Short-period comets originate in the Kuiper belt or its associated scattered disc, long-period comets are thought to originate in the Oort cloud, a spherical cloud of icy bodies extending from outside the Kuiper belt to halfway to the nearest star. Long-period comets are set in motion towards the Sun from the Oort cloud by gravitational perturbations caused by passing stars, hyperbolic comets may pass once through the inner Solar System before being flung to interstellar space. The appearance of a comet is called an apparition, Comets are distinguished from asteroids by the presence of an extended, gravitationally unbound atmosphere surrounding their central nucleus. This atmosphere has parts termed the coma and the tail, however, extinct comets that have passed close to the Sun many times have lost nearly all of their volatile ices and dust and may come to resemble small asteroids. Asteroids are thought to have a different origin from comets, having formed inside the orbit of Jupiter rather than in the outer Solar System, the discovery of main-belt comets and active centaur minor planets has blurred the distinction between asteroids and comets. As of November 2014 there are 5,253 known comets, however, this represents only a tiny fraction of the total potential comet population, as the reservoir of comet-like bodies in the outer Solar System is estimated to be one trillion. Roughly one comet per year is visible to the eye, though many of those are faint. Particularly bright examples are called Great Comets, the word comet derives from the Old English cometa from the Latin comēta or comētēs. That, in turn, is a latinisation of the Greek κομήτης, Κομήτης was derived from κομᾶν, which was itself derived from κόμη and was used to mean the tail of a comet. The astronomical symbol for comets is ☄, consisting of a disc with three hairlike extensions. The solid, core structure of a comet is known as the nucleus, cometary nuclei are composed of an amalgamation of rock, dust, water ice, and frozen gases such as carbon dioxide, carbon monoxide, methane, and ammonia. As such, they are described as dirty snowballs after Fred Whipples model
8.
Lorraine
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Lorraine is a cultural and historical region in north-eastern France, now located in the administrative region of Grand Est. Lorraines name stems from the kingdom of Lotharingia, which in turn was named for either Emperor Lothair I or King Lothair II. It became later the Duchy of Lorraine before it was annexed to France in 1766, from 1982 until January 2016, Lorraine was an administrative region of France, when it became part of the new region Grand Est. As a region in modern France, Lorraine consisted of the four departments Meurthe-et-Moselle, Meuse, Moselle and Vosges, the regional prefecture was Metz, although the largest metropolitan area of Lorraine is Nancy. Lorraine borders Germany, Belgium, and Luxembourg and its inhabitants are called Lorrains in French and number about 2,356,000. Lorraines borders have changed often in its long history, in 840, Charlemagnes son Louis the Pious died, and the Carolingian Empire was divided among Louis three sons by the Treaty of Verdun of 843. On the death of Lothair I, Middle Francia was divided in three by the Treaty of Prüm in 855, with the northern third called Lotharingia and going to Lothair II and this allowed it to be a duchy in name but an independent kingdom in reality. In 870, it allied itself with East Francia while remaining an autonomous duchy, along with the rest of Europe, this prosperity was terminated in Lorraine in the 14th century by a series of harsh winters, bad harvests, and the Black Death. During the Renaissance, a flourishing prosperity returned to Lotharingia until the Thirty Years War, France annexed Lorraine by force in 1766, a condition that remains today. However, the population was mixed, with the north largely Germanic, speaking Lorraine Franconian, in 1871, the German Empire regained a part of Lorraine Bezirk Lothringen, corresponding to the current department of Moselle). The department formed part of the new Imperial German State of Alsace-Lorraine, however, after 1877 higher education, including state-run colleges, universities and teacher seminaries, was exclusively in German. The prevalence of German and the usage of French, though restricted, were both guaranteed by the 1911 constitution of Alsace-Lorraine. In the 1919 Treaty of Versailles, the former German Empire suffered severe territorial losses, with the exception of its de facto annexation by Nazi Germany during World War II, that area has since remained a part of France. During that war, the cross of Lorraine was a symbol of Free France, the administrative region of Lorraine is larger than the 18th century duchy of Lorraine, which gradually came under French sovereignty between 1737 and 1766. The modern region includes provinces and areas that were separate from the duchy of Lorraine proper. These are, Barrois Three Bishoprics, non-contiguous territories around Metz, Verdun, several small principalities which were still part of the Holy Roman Empire at the time of the French Revolution. Some people consider the traditional province of Lorraine as limited to the duchy of Lorraine proper, while other people consider that it includes Barrois, the problem is that this duchy of Lorraine was originally the duchy of upper Lorraine, and did not include the entire area called Lorraine. Thus the duchies of Bar and Lorraine were united in personal union under the same duke, during the French Revolution, four departments were created on the main parts of the territories of Barrois, Three Bishoprics and the Duchy of Lorraine, Meuse, Meurthe, Moselle and Vosges
9.
Kingdom of France
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The Kingdom of France was a medieval and early modern monarchy in Western Europe. It was one of the most powerful states in Europe and a great power since the Late Middle Ages and it was also an early colonial power, with possessions around the world. France originated as West Francia, the half of the Carolingian Empire. A branch of the Carolingian dynasty continued to rule until 987, the territory remained known as Francia and its ruler as rex Francorum well into the High Middle Ages. The first king calling himself Roi de France was Philip II, France continued to be ruled by the Capetians and their cadet lines—the Valois and Bourbon—until the monarchy was overthrown in 1792 during the French Revolution. France in the Middle Ages was a de-centralised, feudal monarchy, in Brittany and Catalonia the authority of the French king was barely felt. Lorraine and Provence were states of the Holy Roman Empire and not yet a part of France, during the Late Middle Ages, the Kings of England laid claim to the French throne, resulting in a series of conflicts known as the Hundred Years War. Subsequently, France sought to extend its influence into Italy, but was defeated by Spain in the ensuing Italian Wars, religiously France became divided between the Catholic majority and a Protestant minority, the Huguenots, which led to a series of civil wars, the Wars of Religion. France laid claim to large stretches of North America, known collectively as New France, Wars with Great Britain led to the loss of much of this territory by 1763. French intervention in the American Revolutionary War helped secure the independence of the new United States of America, the Kingdom of France adopted a written constitution in 1791, but the Kingdom was abolished a year later and replaced with the First French Republic. The monarchy was restored by the great powers in 1814. During the later years of the elderly Charlemagnes rule, the Vikings made advances along the northern and western perimeters of the Kingdom of the Franks, after Charlemagnes death in 814 his heirs were incapable of maintaining political unity and the empire began to crumble. The Treaty of Verdun of 843 divided the Carolingian Empire into three parts, with Charles the Bald ruling over West Francia, the nucleus of what would develop into the kingdom of France. Viking advances were allowed to increase, and their dreaded longboats were sailing up the Loire and Seine rivers and other waterways, wreaking havoc. During the reign of Charles the Simple, Normans under Rollo from Norway, were settled in an area on either side of the River Seine, downstream from Paris, that was to become Normandy. With its offshoots, the houses of Valois and Bourbon, it was to rule France for more than 800 years. Henry II inherited the Duchy of Normandy and the County of Anjou, and married Frances newly divorced ex-queen, Eleanor of Aquitaine, after the French victory at the Battle of Bouvines in 1214, the English monarchs maintained power only in southwestern Duchy of Guyenne. The death of Charles IV of France in 1328 without male heirs ended the main Capetian line, under Salic law the crown could not pass through a woman, so the throne passed to Philip VI, son of Charles of Valois
10.
Great Comet of 1744
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It was discovered independently in late November 1743 by Jan de Munck, in the second week of December by Dirk Klinkenberg, and, four days later, by Jean-Philippe de Chéseaux. It became visible with the eye for several months in 1744 and displayed dramatic. Its absolute magnitude — or intrinsic brightness — of 0.5 was the sixth highest in recorded history and its apparent magnitude may have reached as high as -7, leading it to be classified among what are called the Great Comets. This comet is noted especially for developing a fan of six tails after reaching its perihelion, Chéseaux said it lacked a tail and resembled a nebulous star of the third magnitude, he measured the coma as five minutes across. The comet brightened steadily as it approached perihelion, by February 18,1744, it reportedly was as bright as the planet Venus and at this time displayed a double tail. The comet reached perihelion about March 1,1744, when it was 0.2 astronomical units from the Sun, at about this time it was bright enough to be observed in daylight with the naked eye. As it moved away from perihelion, a spectacular tail developed — extending well above the horizon while the head remained invisible due to the morning twilight. In early March 1744, Chéseaux and several other observers reported an unusual phenomenon — a fan of six separate tails rose above the horizon. The tail structure was a puzzle to astronomers for many years, although other comets had displayed multiple tails on occasion, the 1744 comet was unique by having six. It has been suggested that the fan of tails was generated by as many as three active sources on the nucleus, exposed in turn to solar radiation as the nucleus rotated. It also has proposed that the tail phenomenon was a very prominent example of the dust striae seen in the tails of some comets, such as Comet West. The comet was not seen after April 22,1744, the comet also was noted in Japanese astronomical records in the Nihon Odai Ichiran of the Kanpō era. Among those who saw the comet was the thirteen-year-old Charles Messier, on whom it had a profound and he went on to become a significant figure in astronomy, and later discovered many comets during his observations. Catherine the Great, then Sophia, also observed the brilliant comet as a girl as she was travelling to Russia to be wedded. Orbit Diagram, C/1743 X1 NASA Jet Propulsion Laboratory
11.
Solar eclipse
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As seen from the Earth, a solar eclipse is a type of eclipse that occurs when the Moon passes between the Sun and Earth, and the Moon fully or partially blocks the Sun. This can happen only at new moon when the Sun and the Moon are in conjunction as seen from Earth in an alignment referred to as syzygy, in a total eclipse, the disk of the Sun is fully obscured by the Moon. In partial and annular eclipses, only part of the Sun is obscured, if the Moon were in a perfectly circular orbit, a little closer to the Earth, and in the same orbital plane, there would be total solar eclipses every month. However, the Moons orbit is inclined at more than 5 degrees to the Earths orbit around the Sun, Earths orbit is called the ecliptic plane as the Moons orbit must cross this plane in order for an eclipse to occur. In addition, the Moons actual orbit is elliptical, often taking it far away from Earth that its apparent size is not large enough to block the Sun totally. The orbital planes cross each other at a line of nodes resulting in at least two, and up to five, solar eclipses occurring each year, no more than two of which can be total eclipses. However, total solar eclipses are rare at any particular location because totality exists only along a path on the Earths surface traced by the Moons shadow or umbra. An eclipse is a natural phenomenon, nevertheless, in some ancient and modern cultures, solar eclipses have been attributed to supernatural causes or regarded as bad omens. A total solar eclipse can be frightening to people who are unaware of its explanation, as the Sun seems to disappear during the day. People referred to as eclipse chasers or umbraphiles will travel to locations to observe or witness predicted central solar eclipses. For the date of the next eclipse see the section Recent, during any one eclipse, totality occurs at best only in a narrow track on the surface of Earth. An annular eclipse occurs when the Sun and Moon are exactly in line with the Earth, hence the Sun appears as a very bright ring, or annulus, surrounding the dark disk of the Moon. A hybrid eclipse shifts between a total and annular eclipse, at certain points on the surface of Earth, it appears as a total eclipse, whereas at other points it appears as annular. A partial eclipse occurs when the Sun and Moon are not exactly in line with the Earth and this phenomenon can usually be seen from a large part of the Earth outside of the track of an annular or total eclipse. However, some eclipses can only be seen as an eclipse, because the umbra passes above the Earths polar regions. Partial eclipses are virtually unnoticeable in terms of the suns brightness, even at 99%, it would be no darker than civil twilight. Of course, partial eclipses can be observed if one is viewing the sun through a darkening filter, the Suns distance from Earth is about 400 times the Moons distance, and the Suns diameter is about 400 times the Moons diameter. Because these ratios are approximately the same, the Sun and the Moon as seen from Earth appear to be approximately the same size, about 0.5 degree of arc in angular measure
12.
Joseph-Nicolas Delisle
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Joseph-Nicolas Delisle was a French astronomer and cartographer. He was born in Paris, one of the 11 sons of Claude Delisle, like many of his brothers, among them Guillaume Delisle, he initially followed classical studies. Soon however, he moved to astronomy under the supervision of Joseph Lieutaud, in 1714 he entered the French Academy of Sciences as pupil of Giacomo Filippo Maraldi. Though he was a good scientist and member of a family he did not have much money. In 1712 he set up an observatory at the Luxembourg Palace, from 1719 to 1722 he was employed at the Royal observatory, before returning to his observatory at the Luxembourg Palace. In 1724 he met Edmond Halley in London and, among other things and his life changed radically in 1725 when he was called by the Russian czar Peter the Great to Saint Petersburg to create and run the school of astronomy. He arrived there only in 1726, after the death of the czar and he became quite rich and famous, to such an extent that when he returned to Paris in 1747, he built a new observatory in the palace of Cluny, later made famous by Charles Messier. Also he received the title of Astronomer from the Academy, in Russia he prepared the map of the known North Pacific that was used by Vitus Bering. He was elected a Fellow of the Royal Society in 1725, in 1760 he proposed that the international scientific community coordinate observations of the 1761 Transit of Venus in order to determine the absolute distance of the Earth from the Sun. He developed a map showing where on Earth this transit would be visible, actual implementation of these observational efforts were hindered by the Seven Years War. In 1763 he retired to the Abbey of St Genevieve, dying in Paris sometime in 1768, in 1740 Delisle undertook an expedition to Siberia with the object of observing from Beryozovo the transit of Mercury across the sun. An account of the expedition is given in Volume 72 of the LHistoire générale des voyages. Delisle and his party set out from St. Petersburg on 28 February 1740, arriving in Beryozovo, on the bank of the River Ob, on 9 April, having travelled via Moscow, the Volga, and Tyumen. On 22 April, the date of the transit of Mercury, the sun was obscured by clouds, however, Delisle arrived back in St. Petersburg on 29 December 1740, having sojourned in Tobolsk and Moscow en route. Throughout the expedition, Delisle recorded numerous ornithological, botanical, zoological, geographical and it seems that Delisle even planned to write a general study of the peoples of Siberia. On 30 June 1740, Delisle visited a monastery in Tobolsk, the plan for a map of the Russian Empire was launched by Peter the Great, but did not come to fruition until two decades later, in the reign of Empress Anna. Ivan Kirilov, the first director of the imperial Cartographic Office, had Delisle officially invited to Russia with a view to his collaborating on the map of the empire. Using his own methods, but consulting Delisle for expert advice, Kirilov published in 1734 a general map, the edition was abandoned after Kirilovs death in 1737
13.
French Navy
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The French Navy, informally La Royale, is the maritime arm of the French Armed Forces. As of June 2014, the French Navy employed a total of 36,776 personnel, the reserve element of the French Navy consisted of 4,827 personnel of the Operational Reserve. The French naval fleet includes more than a hundred vessels and nuclear type submarines, the history of the French Navy dates back to the History of the French Navy of Antiquity to the Renaissance, part of the History of the French Navy. The French Royal Navy was quasi inexistent prior 1624, the Ordre de Saint-Jean de Jérusalem, which was both a religious and military order, had its own respective international war fleet which assured the policing of the seas in the Mediterranean. The members which had satisfied obligations for periods in service at sea fulfilling their service, were granted the rank of Knights Hospitaller, however, many considered the naval service formation to integrate later, while being well formed, their respective navy. The Ordre de Saint-Jean de Jérusalem was one of the ancestors of the French naval schools and in principal, the Order accordingly formed most of the ships Captains, Officers of the French Royal Navy and Admirals of the Marine française de guerre de la Méditerranée. During the Revolution, the French Navy succeeded to the French Royal Navy, under the First French Empire and the Second French Empire, the navy was designated as the Imperial French Navy. The French Navy is still designated today familiarly as La Royale and this expression was used by commercial sailors due to their military service at the corps of the navy by the institution of maritime inscription. The implementation then of the Ministère de la Marine later the de la Marine de guerre française at rue Royale. The symbol of the French Navy, which was since origin a golden anchor » and this symbol featured on all naval vessels, the arms, uniforms, the couriers, equipment, and general arms of the navy. This symbol was replaced in 1990 by a logo featuring a bow section of a warship with two ascending red and blue spray foams, and the inscription Marine nationale. The Chief of Staff of the French Navy was Admiral Bernard Louzeau, the navy became a consistent instrument of national power around the seventeenth century with Richelieus efforts under Louis XIII, and Colberts under Louis XIV. Under the tutelage of the Sun King, the French Navy was well-financed and -equipped, managing to score several victories in the Nine Years War against the Royal Navy. Financial troubles, however, forced the navy back to port and allowed the English, before the Nine Years War, in the Franco-Dutch War, it managed to score a decisive victory over a combined Spanish-Dutch fleet at the Battle of Palermo. The French Navy scored various successes, as in the campaigns led in the Atlantic by Picquet de la Motte, in 1766, Bougainville led the first French circumnavigation. During the American Revolutionary War the French Navy played a role in supporting the Americans. French warships participated in the battle by bombarding British ground forces, in India, Suffren waged campaigns against the British, successfully contending for supremacy against Vice-Admiral Sir Edward Hughes. In the Mediterranean, the French Navy waged a campaign during a 1798 French invasion of Egypt
14.
Transit of Mercury
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A transit of Mercury across the Sun takes place when the planet Mercury passes directly between the Sun and a superior planet, becoming visible against the solar disk. During a transit, Mercury appears as a black dot moving across the disk of the Sun. Transits of Mercury with respect to Earth are much more frequent than transits of Venus, with about 13 or 14 per century, in part because Mercury is closer to the Sun, Transits of Mercury occur in May or November. The last four transits occurred on November 15,1999, May 7,2003, November 8,2006, the next will occur on November 11,2019, and then on November 13,2032. A typical transit lasts several hours, on June 3,2014, the Mars rover Curiosity observed the planet Mercury transiting the Sun, marking the first time a planetary transit has been observed from a celestial body besides Earth. More generally, transits can also occur for Venus and were investigated in the context of searching for the inner planet Vulcan. The most common observation to be made at a transit is to record the times when the disk of Mercury appears to be in contact with the limb of the Sun. Those contacts are traditionally referred to as the 1st, 2nd, 3rd and 4th contacts – with the 2nd, observed contact times for transits between 1677 and 1881 are given in S Newcombs analysis of transits of Mercury. Observed 2nd and 3rd contacts times for transits between 1677 and 1973 are given in Royal Greenwich Observatory Bulletin No.181, 359-420. Images of the 1999 Nov 15 transit from the Transition Region, Transits of Mercury can only occur when the Earth is aligned with a node of Mercurys orbit. Currently that alignment occurs within a few days of May 8 and November 10, with the diameter of Mercury being about 12 for May transits. The average date for a transit increases over centuries as a result of the longitude of the nodes of Mercurys orbit increasing by about 1.1 deg per century, Transits of Mercury occur on a regular basis. From the ratio of values, it can be easily shown that Mercury will make an almost integral number of revolutions about the Sun over intervals of 4,6,7,13,33,46,171 and 217 years. In 1894 Crommelin noted that at intervals, the successive paths of Mercury relative to the Sun are consistently displaced northwards or southwards. For November transits, an interval of 6 years is possible but rare, Transits that occur 46 years apart can be grouped into a series. For November transits each series includes about 20 transits over 874 years, for May transits each series includes about 10 transits over 414 years, with the path of Mercury across the Sun passing further south than for the previous transit. Some authors have allocated a number to transits on the basis of this 46-year grouping. Similarly transits that occur 217 years apart can be grouped into a series, for November transits each series would include about 135 transits over 30,000 years
15.
Royal Society
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Founded in November 1660, it was granted a royal charter by King Charles II as The Royal Society. The society is governed by its Council, which is chaired by the Societys President, according to a set of statutes and standing orders. The members of Council and the President are elected from and by its Fellows, the members of the society. As of 2016, there are about 1,600 fellows, allowed to use the postnominal title FRS, there are also royal fellows, honorary fellows and foreign members, the last of which are allowed to use the postnominal title ForMemRS. The Royal Society President is Venkatraman Ramakrishnan, who took up the post on 30 November 2015, since 1967, the society has been based at 6–9 Carlton House Terrace, a Grade I listed building in central London which was previously used by the Embassy of Germany, London. The Royal Society started from groups of physicians and natural philosophers, meeting at variety of locations and they were influenced by the new science, as promoted by Francis Bacon in his New Atlantis, from approximately 1645 onwards. A group known as The Philosophical Society of Oxford was run under a set of rules still retained by the Bodleian Library, after the English Restoration, there were regular meetings at Gresham College. It is widely held that these groups were the inspiration for the foundation of the Royal Society, I will not say, that Mr Oldenburg did rather inspire the French to follow the English, or, at least, did help them, and hinder us. But tis well known who were the men that began and promoted that design. This initial royal favour has continued and, since then, every monarch has been the patron of the society, the societys early meetings included experiments performed first by Hooke and then by Denis Papin, who was appointed in 1684. These experiments varied in their area, and were both important in some cases and trivial in others. The Society returned to Gresham in 1673, there had been an attempt in 1667 to establish a permanent college for the society. Michael Hunter argues that this was influenced by Solomons House in Bacons New Atlantis and, to a lesser extent, by J. V. The first proposal was given by John Evelyn to Robert Boyle in a letter dated 3 September 1659, he suggested a scheme, with apartments for members. The societys ideas were simpler and only included residences for a handful of staff and these plans were progressing by November 1667, but never came to anything, given the lack of contributions from members and the unrealised—perhaps unrealistic—aspirations of the society. During the 18th century, the gusto that had characterised the early years of the society faded, with a number of scientific greats compared to other periods. The pointed lightning conductor had been invented by Benjamin Franklin in 1749, during the same time period, it became customary to appoint society fellows to serve on government committees where science was concerned, something that still continues. The 18th century featured remedies to many of the early problems
16.
Royal Swedish Academy of Sciences
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The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. Every year the Academy awards the Nobel Prizes in Physics and Chemistry, the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel, the Crafoord Prize, the Academy has elected about 1.700 Swedish and 1.200 foreign members since it was founded in 1739. Hansson, appointed from 1 July 2015 The transactions of the Academy were published as its main series between 1739 and 1974, in parallel, other major series have appeared and gone, Öfversigt af Kungl. These lasted into the 1860s, when they were replaced by the single Bihang series, further restructuring of their topics occurred in 1949 and 1974. The purpose of the academy was to focus on practically useful knowledge, the academy was intended to be different from the Royal Society of Sciences in Uppsala, which had been founded in 1719 and published in Latin. The location close to the activities in Swedens capital was also intentional. The academy was modeled after the Royal Society of London and Academie Royale des Sciences in Paris, France, members of the Royal Swedish Academy of Sciences Official website Royal Swedish Academy of Sciences video site
17.
French Academy of Sciences
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The French Academy of Sciences is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at the forefront of developments in Europe in the 17th and 18th centuries. Currently headed by Sébastien Candel, it is one of the five Academies of the Institut de France, the Academy of Sciences makes its origin to Colberts plan to create a general academy. He chose a group of scholars who met on 22 December 1666 in the Kings library. The first 30 years of the Academys existence were relatively informal, in contrast to its British counterpart, the Academy was founded as an organ of government. The Academy was expected to remain apolitical, and to avoid discussion of religious, on 20 January 1699, Louis XIV gave the Company its first rules. The Academy received the name of Royal Academy of Sciences and was installed in the Louvre in Paris, following this reform, the Academy began publishing a volume each year with information on all the work done by its members and obituaries for members who had died. This reform also codified the method by which members of the Academy could receive pensions for their work, on 8 August 1793, the National Convention abolished all the academies. Almost all the old members of the previously abolished Académie were formally re-elected, among the exceptions was Dominique, comte de Cassini, who refused to take his seat. In 1816, the again renamed Royal Academy of Sciences became autonomous, while forming part of the Institute of France, in the Second Republic, the name returned to Académie des sciences. During this period, the Academy was funded by and accountable to the Ministry of Public Instruction, the Academy came to control French patent laws in the course of the eighteenth century, acting as the liaison of artisans knowledge to the public domain. As a result, academicians dominated technological activities in France, the Academy proceedings were published under the name Comptes rendus de lAcadémie des sciences. The Comptes rendus is now a series with seven titles. The publications can be found on site of the French National Library, in 1818 the French Academy of Sciences launched a competition to explain the properties of light. The civil engineer Augustin-Jean Fresnel entered this competition by submitting a new theory of light. Siméon Denis Poisson, one of the members of the judging committee, being a supporter of the particle-theory of light, he looked for a way to disprove it. The Poisson spot is not easily observed in every-day situations, so it was natural for Poisson to interpret it as an absurd result. However, the head of the committee, Dominique-François-Jean Arago, and he molded a 2-mm metallic disk to a glass plate with wax
18.
C/1769 P1
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C/1769 P1 is a long-period comet that was visible to the naked eye at its last apparition in 1769. Because of its outstanding brightness it is called a great comet, on the next evening he saw the nebulosity by unassisted eye and confirmed it to be a comet due to its motion in the sky. On August 15 Messier estimated the length of the tail to be 6°. Giovanni Domenico Maraldi and César François Cassini de Thury saw the comet for the first time on August 22 by telescope, chinese observers reported a “broom star” appearing on August 24 in the southeastern sky. Jean François Marie de Surville observed the comet in the pre-dawn of August 26 from a ship off the Philippines and reported the comet as having a tail, according to observers, throughout the month of August the comet became brighter with a lengthening tail. On August 28 Eustachio Zanotti in Bologna and Messier observed a tail length of about 15°, Captain James Cook aboard the Endeavour in the South Pacific saw the comet for the first time on the pre-dawn of August 30 and measured the tail at 42°. On the 31st of August, Maraldi and Cassini measured the tail at 18°, toward the end of August the comet was observed from many ships, but the reports added little of value to the land-based observations. On September 3 Messier observed a tail length of 36° and on September 5 a tail length of 43°, he reported that the tail was slightly curved, on the following nights, the tail displayed bright parallel rays. The tail became even longer and on September 9 Messier measured a length of 55°. By September 10 when the comet made its closest approach to Earth, according to Messier, the maximum tail length measured for the comet was 97° at Île Bourbon by de la Nux. In September the comet became more difficult to see and the visibility of the tail dwindled, on September 16 Messier saw the comet for the last time before its return after perihelion. Maraldi was able to see the comet in the evening twilight up to September 18, in September Jérôme Lalande had calculated predictive orbital elements, which indicated that the perihelion would occur on October 7. Because of Lallende’s predictions, astronomers began to search for the comet again around the middle of October, at Royal Greenwich Observatory Maskelynes observations on October 23 revealed a short, broad and weakly visible tail. On October 24 Messier saw the comet in the sky with the unassisted eye but difficult to discern. On October 25 Joseph-Louis Lagrange in Milan saw the comet with a dim tail, in November the comet became much dimmer although still followed by many observers, but only Messier made precise measurements. On November 17 the comet was very dim but the tail was still 1. 5° long, after November 18 Messier could only see the comet by telescope. Chinese observers reported that by November 25 the “broom star” had completely disappeared, Messier and Maraldi saw the comet for the last time on December 1. On December 3 Pehr Wilhelm Wargentin became the last observer to report a sighting of the comet, on September 22 the comet’s brightness reached magnitude 0
19.
D/1770 L1
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D/1770 L1, popularly known as Lexells Comet after its orbit computer Anders Johan Lexell, was a comet discovered by astronomer Charles Messier in June 1770. It is notable for having passed closer to Earth than any comet in recorded history. The comet has not been seen since 1770 and is considered a lost comet, the comet was discovered on June 14,1770, in the constellation Sagittarius by Messier, who had just completed an observation of Jupiter and was examining several nebulae. The comet was also noted by other astronomers. The comet was observed in Japan, surviving records identify it as an astronomical and historical phenomenon. It was observed in the Hejaz in Safar 1184 AH, where some believed it to be the predicted by the poet al-Fasi. On July 1,1770, the comet passed 0.015 astronomical units from Earth, Charles Messier measured the coma as 2°23 across, around four times the apparent angular size of the Moon. Messier was the last astronomer to observe the comet as it moved away from the Sun, when it turned out that the parabolic solution was not a good fit to the comets orbit, Anders Johan Lexell suggested that the comet followed an elliptical orbit. His calculations, made over a period of years, gave a perihelion of August 13–14. It is, therefore, the earliest identified Jupiter family comet, the comet was never seen again. The comet likely no longer approaches any closer to the Sun than Jupiters orbit, although Comet Lexell was never seen again, it remained interesting to astronomers. The Paris Academy of Sciences offered a prize for an investigation into the orbit of the comet, johann Karl Burckhardt won in 1801, and confirmed the calculations of Lexell. He calculated that the 1779 close approach to Jupiter drastically altered its orbit and this foreshadowed the modern scientific idea of chaos. Lexells work on the orbit of the comet is considered to be the beginning of understanding of orbit determination. Tanuma Okitsugu, 1719–1788, Forerunner of Modern Japan, OCLC445621 D/1770 L1 Orbit Diagram, NASA JPL
20.
Anders Johan Lexell
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Anders Johan Lexell was a Finnish-Swedish astronomer, mathematician, and physicist who spent most of his life in Imperial Russia, where he was known as Andrei Ivanovich Leksel. Lexell made important discoveries in polygonometry and celestial mechanics, the led to a comet named in his honour. His name was given to a theorem of spherical triangles, Lexell was one of the most prolific members of the Russian Academy of Sciences at that time, having published 66 papers in 16 years of his work there. A statement attributed to Leonhard Euler expresses high approval of Lexells works, Besides Lexell, Lexell was unmarried, and kept up a close friendship with Leonhard Euler and his family. He witnessed Eulers death at his house and succeeded Euler to the chair of the department at the Russian Academy of Sciences. The asteroid 2004 Lexell is named in his honour, as is the lunar crater Lexell, anders Johan Lexell was born in Turku to Johan Lexell, a local administrative officer, and Madeleine-Catherine Björkegren. At the age of fourteen he enrolled at the University of Åbo, in 1763 Lexell moved to Uppsala and worked at Uppsala University as a mathematics lecturer. From 1766 he was a professor of mathematics at the Uppsala Nautical School, in 1762, Catherine the Great ascended to the Russian throne and started the politics of enlightened absolutism. She was aware of the importance of science and ordered to offer Leonhard Euler to state his conditions, to be admitted to the Russian Academy of Sciences, Lexell in 1768 wrote a paper on integral calculus called Methodus integrandi nonnulis aequationum exemplis illustrata. In the same year he received permission from the Swedish king to leave Sweden and his first task was to become familiar with the astronomical instruments that would be used in the observations of the transit of Venus. Lexell made a contribution to Lunar theory and especially to determining the parallax of the Sun from the results of observations of the transit of Venus. He earned universal recognition and, in 1771, when the Russian Academy of Sciences affiliated new members and he was admitted to membership in the Academy of Stockholm and Academy of Uppsala in 1773 and 1774, and became a corresponding member of the Paris Royal Academy of Sciences. Hence, in 1780, Lexell was supposed to leave St. Petersburg and return to Sweden, therefore, Director Domashnev proposed that Lexell travel to Germany, England, and France and then to return to St. Petersburg via Sweden. Lexell made the trip and, to the Academys pleasure, got a discharge from the Swedish King and returned to St. Petersburg in 1781, after more than a year of absence, very satisfied with his trip. Sending academicians abroad was quite rare at that time, so Lexell willingly agreed to make the trip and he was instructed to write his itinerary, which without changes was signed by Domashnev. He should also learn everything about cartography and try to get new geographic, hydrographic, military and he should also write letters to the Academy regularly to report interesting news on science, arts, and literature. In September he left for Bavaria, visiting Leipzig, Göttingen, in October he traveled to Straßbourg and then to Paris, where he spent the winter. In March 1781 he moved to London, in August he left London for Belgium, where he visited Flanders and Brabant, then moved to the Netherlands, visited The Hague, Amsterdam, and Saardam, and then returned to Germany in September
21.
Abraham-Louis Breguet
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Abraham-Louis Breguet, born in Neuchâtel, Switzerland, was a horologist who made many innovations in the course of a career in watchmaking in France. In his lifetime he was considered the leading watchmaker of his day, alongside his friend and contemporary John Arnold, Breguet is now widely acknowledged as one of the greatest horologists of all time. One of his famous ancestors was the Swiss Jean Breguet a Protestant pastor in Neuchâtel very much influenced by the ideas of Jean Calvin and he is the founder of the Breguet company, which is now the luxury watch division of the Swiss Swatch Group. Breguet was born in Neuchâtel, Switzerland to Jonas-Louis Breguet and Suzanne-Marguerite Bollein, Breguets father died in 1758, when he was ten, and his formal schooling ended when he was 12. Breguets mother remarried to Joseph Tattet, who came from a family of watchmakers, at this time the Court had a great influence on the trade and the best watchmakers established themselves around Versailles. Unfortunately, Marie met an end, either through murder or suicide. How he managed this in the period between his parents deaths and the establishment of his business is unknown, Breguet was allowed to marry in 1775 after finishing his apprenticeship. He and his bride, Cécile Marie-Louise LHuillier, set up their home, ca.1812 the firms address was 79, quai de lHorloge du Palais, although Salomons speculated that this might have been merely a change of number and name, not of actual location. By the year of Breguets death in 1823 the firm also had a shop at 4, place de la Bourse, the firm later moved to Rue de la Paix and in the early 20th century to 2, rue Édouard-VII. Breguet invented innovative escapements, including the tourbillon, automatic winding mechanisms, within ten years Breguet had commissions from the aristocratic families of France and even the French queen, Marie-Antoinette. He met Abraham-Louis Perrelet in Switzerland and became a Master Clockmaker in 1784, in 1787 Abraham-Louis established a partnership with Xavier Gide, which lasted until 1791. Ca.1792 the Duke of Orléans went to England and met John Arnold, Europes leading watch, the Duke showed Arnold a clock made by Breguet, who was so impressed that he immediately travelled to Paris and asked Breguet to accept his son as an apprentice. As Breguets fame gradually increased he became friendly with revolutionary leader Jean-Paul Marat, Salomons biography records that Marat and Breguet were at the house of a mutual friend one day when an angry crowd gathered outside, shouting Down with Marat. But Breguet contrived their escape by disguising Marat as an old woman and he remained there for two years, during which time he worked for King George III. When the political scene in France stabilised, Breguet returned to Paris, in 1795 Breguet returned to Paris with many ideas for innovations in watch and clock making. He set up again in Quai de lHorloge and quickly established a reputation among the new wealthy classes in the Empire. Breguet met another watchmaker Louis Moinet, recognised his worth at once, from 1811 on, Moinet became Breguets personal adviser. Breguet became a member of the Board of Longitude in 1814 and he entered the French Academy of Sciences in 1816 as a full member, and received the Chevalier of the Legion of Honour from the hands of Louis XVIII in 1819
22.
Orion Nebula
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The Orion Nebula is a diffuse nebula situated in the Milky Way, being south of Orions Belt in the constellation of Orion. It is one of the brightest nebulae, and is visible to the eye in the night sky. M42 is located at a distance of 1,344 ±20 light years and is the closest region of star formation to Earth. The M42 nebula is estimated to be 24 light years across and it has a mass of about 2000 times the mass of the Sun. Older texts frequently refer to the Orion Nebula as the Great Nebula in Orion or the Great Orion Nebula, the Orion Nebula is one of the most scrutinized and photographed objects in the night sky, and is among the most intensely studied celestial features. The nebula has revealed much about the process of how stars and planetary systems are formed from collapsing clouds of gas, astronomers have directly observed protoplanetary disks, brown dwarfs, intense and turbulent motions of the gas, and the photo-ionizing effects of massive nearby stars in the nebula. The nebula is visible with the eye even from areas affected by some light pollution. It is seen as the star in the sword of Orion. The star appears fuzzy to sharp-eyed observers, and the nebulosity is obvious through binoculars or a small telescope, the peak surface brightness of the central region is about 17 Mag/arcsec2 and the outer bluish glow has a peak surface brightness of 21.3 Mag/arcsec2. The Orion Nebula contains a young open cluster, known as the Trapezium due to the asterism of its primary four stars. Two of these can be resolved into their component binary systems on nights with good seeing, giving a total of six stars, the stars of the Trapezium, along with many other stars, are still in their early years. The Trapezium is a component of the much larger Orion Nebula Cluster, observers have long noted a distinctive greenish tint to the nebula, in addition to regions of red and of blue-violet. The red hue is a result of the Hα recombination line radiation at a wavelength of 656.3 nm, the blue-violet coloration is the reflected radiation from the massive O-class stars at the core of the nebula. The green hue was a puzzle for astronomers in the part of the 20th century because none of the known spectral lines at that time could explain it. There was some speculation that the lines were caused by a new element, and this radiation was all but impossible to reproduce in the laboratory at the time, because it depended on the quiescent and nearly collision-free environment found in the high vacuum of deep space. This has led to speculation that a flare-up of the illuminating stars may have increased the brightness of the nebula. The first published observation of the nebula was by the Jesuit mathematician, charles Messier first noted the nebula on March 4,1769, and he also noted three of the stars in Trapezium. Messier published the first edition of his catalog of deep sky objects in 1774, as the Orion Nebula was the 42nd object in his list, it became identified as M42
23.
Galaxy
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A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. The word galaxy is derived from the Greek galaxias, literally milky, Galaxies range in size from dwarfs with just a few billion stars to giants with one hundred trillion stars, each orbiting its galaxys center of mass. Galaxies are categorized according to their morphology as elliptical, spiral. Many galaxies are thought to have holes at their active centers. The Milky Ways central black hole, known as Sagittarius A*, has a four million times greater than the Sun. Recent estimates of the number of galaxies in the observable universe range from 200 billion to 2 trillion or more, most of the galaxies are 1,000 to 100,000 parsecs in diameter and separated by distances on the order of millions of parsecs. The space between galaxies is filled with a gas having an average density of less than one atom per cubic meter. The majority of galaxies are organized into groups, clusters. At the largest scale, these associations are generally arranged into sheets and filaments surrounded by immense voids. In Greek mythology, Zeus places his son born by a mortal woman, the infant Heracles, on Heras breast while she is asleep so that the baby will drink her divine milk and will thus become immortal. Hera wakes up while breastfeeding and then realizes she is nursing a baby, she pushes the baby away, some of her milk spills and. In the astronomical literature, the capitalized word Galaxy is often used to refer to our galaxy, the Milky Way, to distinguish it from the other galaxies in our universe. The English term Milky Way can be traced back to a story by Chaucer c. 1380, See yonder, lo, the Galaxyë Which men clepeth the Milky Wey, For hit is whyt. However, the word Universe was later understood to mean the entirety of existence, so this expression fell into disuse and the objects instead became known as galaxies. Tens of thousands of galaxies have been catalogued, but only a few have well-established names, such as the Andromeda Galaxy, the Magellanic Clouds, the Whirlpool Galaxy, and the Sombrero Galaxy. Astronomers work with numbers from certain catalogues, such as the Messier catalogue, the NGC, the IC, the CGCG, all of the well-known galaxies appear in one or more of these catalogues but each time under a different number. For example, Messier 109 is a galaxy having the number 109 in the catalogue of Messier, but also codes NGC3992, UGC6937, CGCG 269-023, MCG +09-20-044. One of the arguments to do so is that these impressive objects deserve better than uninspired codes, for instance, Bodifee and Berger propose the informal, descriptive name Callimorphus Ursae Majoris for the well-formed barred galaxy Messier 109 in Ursa Major
24.
Planetary nebula
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A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from old red giant stars late in their lives. Herschels name for these objects was popularly adopted and has not been changed and they are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years. After most of the red giants atmosphere is dissipated, the radiation of the hot luminous core, called a planetary nebula nucleus. Absorbed ultraviolet light energises the shell of gas around the central star. Planetary nebulae likely play a role in the chemical evolution of the Milky Way by expelling elements to the interstellar medium from stars where those elements were created. Planetary nebulae are also observed in distant galaxies, yielding useful information about their chemical abundances. Starting from the 1990s, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex, about one-fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms that produce such a variety of shapes and features are not yet well understood. The first planetary nebula discovered was the Dumbbell Nebula in the constellation of Vulpecula and it was observed by Charles Messier in 1764 and listed as M27 in his catalogue of nebulous objects. To early observers with telescopes, M27 and subsequently discovered planetary nebulae resembled the giant planets like Uranus. William Herschel, discoverer of Uranus, eventually coined the term planetary nebula, the nature of planetary nebulae was unknown until the first spectroscopic observations were made in the mid-19th century. Using a prism to disperse their light, William Huggins was one of the earliest astronomers to study the spectra of astronomical objects. On August 29,1864, Huggins was the first to analyze the spectrum of a planetary nebula when he observed Cats Eye Nebula and his observations of stars showed that their spectra consisted of a continuum of radiation with many dark lines superimposed. He later found that many objects such as the Andromeda Nebula had spectra that were quite similar. Those nebulae were later shown to be collections of stars now called galaxies, however, when Huggins looked at the Cats Eye Nebula, he found a very different spectrum. Rather than a strong continuum with absorption lines superimposed, the Cats Eye Nebula, the brightest of these was at a wavelength of 500.7 nanometres, which did not correspond with a line of any known element. At first, it was hypothesized that the line might be due to an unknown element, a similar idea had led to the discovery of helium through analysis of the Suns spectrum in 1868. While helium was isolated on Earth soon after its discovery in the spectrum of the Sun, nebulium was not
25.
Refracting telescope
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A refracting telescope is a type of optical telescope that uses a lens as its objective to form an image. The refracting telescope design was used in spy glasses and astronomical telescopes but is also used for long focus camera lenses. A refractors magnification is calculated by dividing the length of the objective lens by that of the eyepiece. Refractors were the earliest type of optical telescope, Galileo Galilei, happening to be in Venice in about the month of May 1609, heard of the invention and constructed a version of his own. Galileo then communicated the details of his invention to the public, all refracting telescopes use the same principles. The objective in a refracting telescope refracts or bends light and this refraction causes parallel light rays to converge at a focal point, while those not parallel converge upon a focal plane. The telescope converts a bundle of rays to make an angle α. The ratio β/α is called the angular magnification and it equals the ratio between the retinal image sizes obtained with and without the telescope. Refracting telescopes can come in different configurations to correct for image orientation. Because the image was formed by the bending of light, or refraction, the design Galileo Galilei used in 1609 is commonly called a Galilean telescope. It used a convergent objective lens and a divergent eyepiece lens, a Galilean telescope, because the design has no intermediary focus, results in a non-inverted and upright image. Galileo’s best telescope magnified objects about 30 times, because of flaws in its design, such as the shape of the lens and the narrow field of view, the images were blurry and distorted. Despite these flaws, the telescope was still enough for Galileo to explore the sky. The Galilean telescope could view the phases of Venus, and was able to see craters on the Moon, parallel rays of light from a distant object would be brought to a focus in the focal plane of the objective lens. The eyepiece lens intercepts these rays and renders them parallel once more, non-parallel rays of light from the object traveling at an angle α1 to the optical axis travel at a larger angle after they passed through the eyepiece. This leads to an increase in the apparent angular size and is responsible for the perceived magnification, the final image is a virtual image, located at infinity and is the same way up as the object. The Keplerian telescope, invented by Johannes Kepler in 1611, is an improvement on Galileos design and it uses a convex lens as the eyepiece instead of Galileos concave one. The advantage of this arrangement is that the rays of light emerging from the eyepiece are converging and this allows for a much wider field of view and greater eye relief, but the image for the viewer is inverted
26.
Paris
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Paris is the capital and most populous city of France. It has an area of 105 square kilometres and a population of 2,229,621 in 2013 within its administrative limits, the agglomeration has grown well beyond the citys administrative limits. By the 17th century, Paris was one of Europes major centres of finance, commerce, fashion, science, and the arts, and it retains that position still today. The aire urbaine de Paris, a measure of area, spans most of the Île-de-France region and has a population of 12,405,426. It is therefore the second largest metropolitan area in the European Union after London, the Metropole of Grand Paris was created in 2016, combining the commune and its nearest suburbs into a single area for economic and environmental co-operation. Grand Paris covers 814 square kilometres and has a population of 7 million persons, the Paris Region had a GDP of €624 billion in 2012, accounting for 30.0 percent of the GDP of France and ranking it as one of the wealthiest regions in Europe. The city is also a rail, highway, and air-transport hub served by two international airports, Paris-Charles de Gaulle and Paris-Orly. Opened in 1900, the subway system, the Paris Métro. It is the second busiest metro system in Europe after Moscow Metro, notably, Paris Gare du Nord is the busiest railway station in the world outside of Japan, with 262 millions passengers in 2015. In 2015, Paris received 22.2 million visitors, making it one of the top tourist destinations. The association football club Paris Saint-Germain and the rugby union club Stade Français are based in Paris, the 80, 000-seat Stade de France, built for the 1998 FIFA World Cup, is located just north of Paris in the neighbouring commune of Saint-Denis. Paris hosts the annual French Open Grand Slam tennis tournament on the red clay of Roland Garros, Paris hosted the 1900 and 1924 Summer Olympics and is bidding to host the 2024 Summer Olympics. The name Paris is derived from its inhabitants, the Celtic Parisii tribe. Thus, though written the same, the name is not related to the Paris of Greek mythology. In the 1860s, the boulevards and streets of Paris were illuminated by 56,000 gas lamps, since the late 19th century, Paris has also been known as Panam in French slang. Inhabitants are known in English as Parisians and in French as Parisiens and they are also pejoratively called Parigots. The Parisii, a sub-tribe of the Celtic Senones, inhabited the Paris area from around the middle of the 3rd century BC. One of the areas major north-south trade routes crossed the Seine on the île de la Cité, this place of land and water trade routes gradually became a town
27.
France
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France, officially the French Republic, is a country with territory in western Europe and several overseas regions and territories. The European, or metropolitan, area of France extends from the Mediterranean Sea to the English Channel and the North Sea, Overseas France include French Guiana on the South American continent and several island territories in the Atlantic, Pacific and Indian oceans. France spans 643,801 square kilometres and had a population of almost 67 million people as of January 2017. It is a unitary republic with the capital in Paris. Other major urban centres include Marseille, Lyon, Lille, Nice, Toulouse, during the Iron Age, what is now metropolitan France was inhabited by the Gauls, a Celtic people. The area was annexed in 51 BC by Rome, which held Gaul until 486, France emerged as a major European power in the Late Middle Ages, with its victory in the Hundred Years War strengthening state-building and political centralisation. During the Renaissance, French culture flourished and a colonial empire was established. The 16th century was dominated by civil wars between Catholics and Protestants. France became Europes dominant cultural, political, and military power under Louis XIV, in the 19th century Napoleon took power and established the First French Empire, whose subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a succession of governments culminating with the establishment of the French Third Republic in 1870. Following liberation in 1944, a Fourth Republic was established and later dissolved in the course of the Algerian War, the Fifth Republic, led by Charles de Gaulle, was formed in 1958 and remains to this day. Algeria and nearly all the colonies became independent in the 1960s with minimal controversy and typically retained close economic. France has long been a centre of art, science. It hosts Europes fourth-largest number of cultural UNESCO World Heritage Sites and receives around 83 million foreign tourists annually, France is a developed country with the worlds sixth-largest economy by nominal GDP and ninth-largest by purchasing power parity. In terms of household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, France remains a great power in the world, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a member state of the European Union and the Eurozone. It is also a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, originally applied to the whole Frankish Empire, the name France comes from the Latin Francia, or country of the Franks
28.
Celestial pole
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The north and south celestial poles are the two imaginary points in the sky where the Earths axis of rotation, indefinitely extended, intersects the celestial sphere. The north and south celestial poles appear permanently directly overhead to an observer at the Earths North Pole and South Pole respectively. As the Earth spins on its axis, the two celestial poles remain fixed in the sky, and all other points appear to rotate around them, completing one circuit per day. The celestial poles are also the poles of the equatorial coordinate system, meaning they have declinations of +90 degrees. The celestial poles do not remain permanently fixed against the background of the stars, because of a phenomenon known as the precession of the equinoxes, the poles trace out circles on the celestial sphere, with a period of about 25,700 years. The Earths axis is subject to other complex motions which cause the celestial poles to shift slightly over cycles of varying lengths, see nutation, polar motion. Finally, over long periods the positions of the stars themselves change. An analogous concept applies to other planets, a planets celestial poles are the points in the sky where the projection of the axis of rotation intersects the celestial sphere. These points vary because different planets axes are oriented differently, Celestial bodies other than Earth also have similarly defined celestial poles. The north celestial pole currently is within a degree of the bright star Polaris, Polaris can, of course, only be seen from locations in the northern hemisphere. Polaris is near the pole for only a small fraction of the 25. It will remain a good approximation for about 1,000 years, to find Polaris, face north and locate the Big Dipper and Little Dipper asterisms. Looking at the cup part of the Big Dipper, imagine that the two stars at the edge of the cup form a line pointing upward out of the cup. This line points directly at the star at the tip of the Little Dippers handle and that star is Polaris, the North Star. The south celestial pole is only from the southern hemisphere. It lies in the dim constellation Octans, the Octant, sigma Octantis is identified as the south pole star, over a degree away from the pole, but with a magnitude of 5.5 it is barely visible on a clear night. The south celestial pole can be located from the Southern Cross, draw an imaginary line from γ Crucis to α Crucis—the two stars at the extreme ends of the long axis of the cross—and follow this line through the sky. This point is 5 or 6 degrees from the celestial pole
29.
Sombrero Galaxy
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Sombrero Galaxy is an unbarred spiral galaxy in the constellation Virgo located 31 million light-years from Earth. The galaxy has a diameter of approximately 50,000 light-years and it has a bright nucleus, an unusually large central bulge, and a prominent dust lane in its inclined disk. The dark dust lane and the bulge give this galaxy the appearance of a sombrero and its large bulge, its central supermassive black hole, and its dust lane all attract the attention of professional astronomers. The Sombrero Galaxy was discovered on May 11,1781 by Pierre Méchain, charles Messier made a hand-written note about this and five other objects to his personal list of objects now known as the Messier Catalogue, but it was not officially included until 1921. William Herschel independently discovered the object in 1784 and additionally noted the presence of a stratum in the galaxys disc. Later astronomers were able to connect Méchains and Herschels observations, in 1921, Camille Flammarion found Messiers personal list of the Messier objects including the hand-written notes about the Sombrero Galaxy. This was identified with object 4594 in the New General Catalogue, since this time, the Sombrero Galaxy has been known as M104. As noted above, this galaxys most striking feature is the dust lane that crosses in front of the bulge of the galaxy and this dust lane is actually a symmetrical ring that encloses the bulge of the galaxy. Most of the atomic hydrogen gas and the dust lie within this ring. The ring might also contain most of the Sombrero Galaxys cold molecular gas, although this is an based on observations with low resolution. Additional observations are needed to confirm that the Sombrero galaxys molecular gas is constrained to the ring, based on infrared spectroscopy, the dust ring is the primary site of star formation within this galaxy. The nucleus of the Sombrero galaxy is classified as a low ionization nuclear emission region and these are nuclear regions where ionized gas is present, but the ions are only weakly ionized. The source of energy for ionizing the gas in LINERs has been debated extensively, some LINER nuclei may be powered by hot, young stars found in star formation regions, whereas other LINER nuclei may be powered by active galactic nuclei. Infrared spectroscopy observations have demonstrated that the nucleus of the Sombrero Galaxy is probably devoid of any significant star formation activity. However, a black hole has been identified in the nucleus. In the 1990s, a group led by John Kormendy demonstrated that a supermassive black hole is present within the Sombrero Galaxy. This is among the most massive black holes measured in any nearby galaxies, at radio and X-ray wavelengths, the nucleus is a strong source of synchrotron emission. Synchrotron emission is produced when high velocity electrons oscillate as they pass through regions with strong magnetic fields and this emission is quite common for active galactic nuclei
30.
Messier 110
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Messier 110, also known as NGC205, is a dwarf elliptical galaxy that is a satellite of the Andromeda Galaxy. M110 contains some dust and hints of recent star formation, which is unusual for dwarf elliptical galaxies in general, the galaxy was independently discovered by Caroline Herschel on August 27,1783, her brother William Herschel described her discovery in 1785. The suggestion to assign the galaxy a Messier number was made by Kenneth Glyn Jones in 1967, a few novae have been detected in this galaxy, including one discovered in 1999 by Johnson and Modjaz, and another detected in 2002, by Nakano and Sumoto. The latter, designated EQ J004015. 8+414420, had also captured in images taken by the Sloan Digital Sky Survey in October,2002. Unlike M32, NGC205 does not show evidence for a black hole at its center
31.
Crab Nebula
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The Crab Nebula is a supernova remnant in the constellation of Taurus. The now-current name is due to William Parsons, 3rd Earl of Rosse, corresponding to a bright supernova recorded by Chinese astronomers in 1054, the nebula was observed later by English astronomer John Bevis in 1731. The nebula was the first astronomical object identified with a supernova explosion. At an apparent magnitude of 8.4, comparable to that of Saturns moon Titan, it is not visible to the naked eye, the nebula lies in the Perseus Arm of the Milky Way galaxy, at a distance of about 2.0 kiloparsecs from Earth. It has a diameter of 3.4 parsecs, corresponding to an apparent diameter of some 7 arcminutes, and is expanding at a rate of about 1,500 kilometres per second, or 0. 5% of the speed of light. At the center of the lies the Crab Pulsar, a neutron star 28–30 kilometres across with a spin rate of 30.2 times per second. At X-ray and gamma ray energies above 30 keV, the Crab Nebula is generally the strongest persistent source in the sky, the nebulas radiation allows for the detailed studying of celestial bodies that occult it. The inner part of the nebula is a much smaller pulsar wind nebula that appears as a shell surrounding the pulsar, for the Crab Nebula, the divisions are superficial but remain meaningful to researchers and their lines of study. Modern understanding that the Crab Nebula was created by a supernova dates to 1921 and this eventually led to the conclusion that the creation of the Crab Nebula corresponds to the bright SN1054 supernova recorded by Chinese astronomers in AD1054. There is also a 13th-century Japanese reference to this guest star in Meigetsuki, the Crab Nebula was first identified in 1731 by John Bevis. The nebula was independently rediscovered in 1758 by Charles Messier as he was observing a bright comet and it is in searching in vain for the comet that Charles Messier found the Crab nebula, which he at first thought to be Halleys comet. After some observation, noticing that the object that he was observing was not moving across the sky, Messier then realised the usefulness of compiling a catalogue of celestial objects of a cloudy nature, but fixed in the sky, to avoid incorrectly cataloguing them as comets. After several observations, he concluded that it was composed of a group of stars. The 3rd Earl of Rosse observed the nebula at Birr Castle in 1844 using a 36-inch telescope and he observed it again later, in 1848, using a 72-inch telescope and could not confirm the supposed resemblance, but the name stuck nevertheless. In 1913, when Vesto Slipher registered his spectroscopy study of the sky, in the early twentieth century, the analysis of early photographs of the nebula taken several years apart revealed that it was expanding. Tracing the expansion back revealed that the nebula must have become visible on Earth about 900 years ago, historical records revealed that a new star bright enough to be seen in the daytime had been recorded in the same part of the sky by Chinese astronomers in 1054. Changes in the cloud, suggesting its small extent, were discovered by Carl Lampland in 1921 and that same year, John Charles Duncan demonstrated that the remnant is expanding, while Knut Lundmark noted its proximity to the guest star of 1054.5 by July. The supernova was visible to the eye for about two years after its first observation
32.
Amateur astronomy
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Amateur astronomy is a hobby whose participants enjoy watching the sky, and the abundance of objects found in it with the unaided eye, binoculars, or telescopes. Many amateurs are beginners or hobbyists, while others have a degree of experience in astronomy and often assist. Amateur astronomers often look at the sky using nothing more than their eyes, people have studied the sky throughout history in an amateur framework, without any formal method of funding. It is only within about the past century, however, that amateur astronomy has become an activity clearly distinguished from professional astronomy, collectively, amateur astronomers observe a variety of celestial objects and phenomena. Common targets of amateur astronomers include the Moon, planets, stars, comets, meteor showers, and a variety of deep sky objects such as clusters, galaxies. Many amateurs like to specialise in observing particular objects, types of objects, one branch of amateur astronomy, amateur astrophotography, involves the taking of photos of the night sky. Most amateur astronomers work at visible wavelengths, but a small minority experiment with wavelengths outside the visible spectrum, non-visual amateur astronomy includes the use of infrared filters on conventional telescopes, and also the use of radio telescopes. Some amateur astronomers use home-made radio telescopes, while others use radio telescopes that were built for astronomy research but have since been made available for use by amateurs. The One-Mile Telescope is one such example, Amateur astronomers use a range of instruments to study the sky, depending on a combination of their interests and resources. Commercial telescopes are available, new and used, but it is common for amateur astronomers to build their own custom telescopes. Some people even focus on amateur telescope making as their primary interest within the hobby of amateur astronomy, although specialized and experienced amateur astronomers tend to acquire more specialized and more powerful equipment over time, relatively simple equipment is often preferred for certain tasks. Amateur astronomers also use star charts that, depending on experience and intentions, Amateur astronomers often like to keep records of their observations, which usually takes the form of an observing log. Observing logs typically record details about which objects were observed and when, sketching is sometimes used within logs, and photographic records of observations have also been used in recent times. The information gathered is used to help studies and interactions between amateur astronomers in yearly gatherings, although not professional information or credible, it is a way for the hobby lovers to share their new sightings and experiences. The Internet is a tool of amateur astronomers. The popularity of CCD imaging among amateurs has led to large numbers of web sites being written by individuals about their images, much of the social interaction of amateur astronomy occurs on mailing lists or discussion groups. Discussion group servers host numerous astronomy lists, a great deal of the commerce of amateur astronomy, the buying and selling of equipment, occurs online. Many amateurs use online tools to plan their observing sessions using tools such as the Clear Sky Chart
33.
Messier (crater)
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Messier is a relatively young lunar impact crater located on the Mare Fecunditatis. The crater has an oblong shape that is not caused by foreshortening. The longer dimension is oriented in an east–west direction, just to the west lies Messier A, a similar-sized crater with an oblong, doublet form. The longer dimension of this crater is oriented north–south, at angles to Messier. This crater also has a curved bulge extending to the west, Messier and Messier A were photographed at high resolution by NASAs Lunar Orbiter 5 spacecraft In August 1967. The Lunar Orbiter V_041 image is archived at the Lunar and Planetary Institute website, the Lunar Orbiter V partial image shown here is derived from the Lunar Orbiter Image Recovery Project effort to reprocess these images from the original tapes. The interiors of Messier and Messier A have a higher albedo than the surrounding mare, there is also a dark streak in the center of each crater. Two prominent, nearly linear rays extend westwards from the rim of Messier A, the mare surface around the craters is also lightly marked by rays from other craters. It is theorized that Messier crater was formed by an impact at a low angle. The low angle of impact may also explain the asymmetrical ray system, to the northwest of Messier A is a long, narrow rille, called Rima Messier. This crater is named in honor of the French astronomer Charles Messier, by convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Messier. The following crater has been renamed by the IAU, Messier A has been called W. H. Pickering, but this was never officially sanctioned by the IAU. A different crater has since named for Pickering. Sky & Telescope, August 1,2006
34.
Moon
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The Moon is an astronomical body that orbits planet Earth, being Earths only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, following Jupiters satellite Io, the Moon is second-densest satellite among those whose densities are known. The average distance of the Moon from the Earth is 384,400 km, the Moon is thought to have formed about 4.51 billion years ago, not long after Earth. It is the second-brightest regularly visible celestial object in Earths sky, after the Sun and its surface is actually dark, although compared to the night sky it appears very bright, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its cycle of phases have made the Moon an important cultural influence since ancient times on language, calendars, art. The Moons gravitational influence produces the ocean tides, body tides, and this matching of apparent visual size will not continue in the far future. The Moons linear distance from Earth is currently increasing at a rate of 3.82 ±0.07 centimetres per year, since the Apollo 17 mission in 1972, the Moon has been visited only by uncrewed spacecraft. The usual English proper name for Earths natural satellite is the Moon, the noun moon is derived from moone, which developed from mone, which is derived from Old English mōna, which ultimately stems from Proto-Germanic *mǣnōn, like all Germanic language cognates. Occasionally, the name Luna is used, in literature, especially science fiction, Luna is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of our moon. The principal modern English adjective pertaining to the Moon is lunar, a less common adjective is selenic, derived from the Ancient Greek Selene, from which is derived the prefix seleno-. Both the Greek Selene and the Roman goddess Diana were alternatively called Cynthia, the names Luna, Cynthia, and Selene are reflected in terminology for lunar orbits in words such as apolune, pericynthion, and selenocentric. The name Diana is connected to dies meaning day, several mechanisms have been proposed for the Moons formation 4.51 billion years ago, and some 60 million years after the origin of the Solar System. These hypotheses also cannot account for the angular momentum of the Earth–Moon system. This hypothesis, although not perfect, perhaps best explains the evidence, eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, and Jeff Taylor challenged fellow lunar scientists, You have eighteen months. Go back to your Apollo data, go back to computer, do whatever you have to. Dont come to our conference unless you have something to say about the Moons birth, at the 1984 conference at Kona, Hawaii, the giant impact hypothesis emerged as the most popular. Afterward there were only two groups, the giant impact camp and the agnostics. Giant impacts are thought to have been common in the early Solar System, computer simulations of a giant impact have produced results that are consistent with the mass of the lunar core and the present angular momentum of the Earth–Moon system
35.
Asteroid
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Asteroids are minor planets, especially those of the inner Solar System. The larger ones have also been called planetoids and these terms have historically been applied to any astronomical object orbiting the Sun that did not show the disc of a planet and was not observed to have the characteristics of an active comet. As minor planets in the outer Solar System were discovered and found to have volatile-based surfaces that resemble those of comets, in this article, the term asteroid refers to the minor planets of the inner Solar System including those co-orbital with Jupiter. There are millions of asteroids, many thought to be the remnants of planetesimals. The large majority of known asteroids orbit in the belt between the orbits of Mars and Jupiter, or are co-orbital with Jupiter. However, other orbital families exist with significant populations, including the near-Earth objects, individual asteroids are classified by their characteristic spectra, with the majority falling into three main groups, C-type, M-type, and S-type. These were named after and are identified with carbon-rich, metallic. The size of asteroids varies greatly, some reaching as much as 1000 km across, asteroids are differentiated from comets and meteoroids. In the case of comets, the difference is one of composition, while asteroids are composed of mineral and rock, comets are composed of dust. In addition, asteroids formed closer to the sun, preventing the development of the aforementioned cometary ice, the difference between asteroids and meteoroids is mainly one of size, meteoroids have a diameter of less than one meter, whereas asteroids have a diameter of greater than one meter. Finally, meteoroids can be composed of either cometary or asteroidal materials, only one asteroid,4 Vesta, which has a relatively reflective surface, is normally visible to the naked eye, and this only in very dark skies when it is favorably positioned. Rarely, small asteroids passing close to Earth may be visible to the eye for a short time. As of March 2016, the Minor Planet Center had data on more than 1.3 million objects in the inner and outer Solar System, the United Nations declared June 30 as International Asteroid Day to educate the public about asteroids. The date of International Asteroid Day commemorates the anniversary of the Tunguska asteroid impact over Siberia, the first asteroid to be discovered, Ceres, was found in 1801 by Giuseppe Piazzi, and was originally considered to be a new planet. In the early half of the nineteenth century, the terms asteroid. Asteroid discovery methods have improved over the past two centuries. This task required that hand-drawn sky charts be prepared for all stars in the band down to an agreed-upon limit of faintness. On subsequent nights, the sky would be charted again and any moving object would, hopefully, the expected motion of the missing planet was about 30 seconds of arc per hour, readily discernible by observers
36.
Deep-sky object
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Deep-sky objects are astronomical objects other than individual stars and Solar System objects. The classification is used for the most part by amateur astronomers to denote visually observed faint naked eye and telescopic objects such as clusters, nebulae. Classifying non-stellar astronomical objects began soon after the invention of the telescope, as telescopes improved these faint nebulae would be broken into more descriptive scientific classifications such as interstellar clouds, star clusters, and galaxies. Deep-sky object, as a classification for these objects, has its origins in the modern field of amateur astronomy. There are many amateur astronomical techniques and activities associated with deep-sky objects, some of these objects are bright enough to find and see in binoculars and small telescopes. But the faintest objects need the power of telescopes with large objectives. Observing faint objects needs dark skies, so these relatively portable types of telescopes also lend themselves to the majority of amateurs who need to travel outside light polluted urban locations. To cut down light pollution and enhance contrast observers employ nebular filters designed to admit certain wavelength, there are organized activities associated with DSOs such as the Messier marathon which occurs at a specific time each year and involve observers trying to spot all 110 Messier objects in one night. Since the Messier catalog objects were discovered with relatively small 18th century telescopes it is a popular list with observers, a much more demanding test known as the Herschel 400 is designed to tax larger telescopes and experienced amateur astronomers. There are many astronomical object types that come under the description of deep-sky objects, Jess K. Gilmour, The practical astronomers deep-sky companion. W. H. Finlay, Concise Catalog of Deep-sky Objects, Astrophysical Information for 500 Galaxies, Clusters, includes the Messier objects, Herschel 400 & more. Roger Nelson Clark, Visual astronomy of the deep sky, burnhams Celestial Handbook by Robert Burnham, Jr. Deep Sky Observers Guide by Neil Bone, Wil Tirion, the practical astronomers deep-sky companion by Jess K. Gilmour. Concise Catalog of Deep-sky Objects, Astrophysical Information for 500 Galaxies, Clusters, includes the Messier objects, Herschel 400 & more Visual astronomy of the deep sky by Roger Nelson Clark
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Messier marathon
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A Messier marathon is an attempt, usually organized by amateur astronomers, to find as many Messier objects as possible during one night. The Messier catalogue was compiled by French astronomer Charles Messier during the late 18th century, the number of Messier objects visible in any one night varies depending on a few factors, including the location of the observer, the duration of daylight and nighttime, and the season. Because Messier compiled his catalog from a northern latitude, not all of the Messier objects are visible from the southern hemisphere. In particular, M81, M82, M52, and M103 make southern-hemisphere Messier marathons difficult, although a Messier marathon can be attempted from any northern latitude, low northern latitudes are best. In particular, a latitude of around 25° north lends the best possibility to complete a Messier marathon at the time of year. At low northern latitudes, particularly around latitude 25° north, it is possible to observe all Messier objects in one night during a window of a few weeks from mid-March to early April. In that period the dark nights around the time of the new moon are best for a Messier marathon, less complete Messier marathons can be undertaken at other times of the year, with the actual percentage of Messier objects seen depending upon season and location. In particular, there is a period around the autumnal equinox when most of the objects can be seen. Typically an observer attempting a Messier marathon begins observing at sundown, an observer starts with objects low in the western sky at sunset, hoping to view them before they dip out of view, then works eastward across the sky. By sunrise, the observer will be observing the last few objects low on the eastern horizon. The evening can be a test of stamina and willpower depending on weather conditions, particularly crowded regions of the sky can prove to be challenging to an observer as well, and a Messier marathon will generally budget time for these regions accordingly. Marathons are typically organized by a local organization or astronomical society as a special type of star party. These are usually attempted at least once every year, some clubs issue certificates/awards either for participation or for achieving a set number of objects. Includes tips for preparations as well as for difficult portions of the marathon
38.
Cambridge University Press
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Cambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the worlds oldest publishing house and it also holds letters patent as the Queens Printer. The Presss mission is To further the Universitys mission by disseminating knowledge in the pursuit of education, learning, Cambridge University Press is a department of the University of Cambridge and is both an academic and educational publisher. With a global presence, publishing hubs, and offices in more than 40 countries. Its publishing includes journals, monographs, reference works, textbooks. Cambridge University Press is an enterprise that transfers part of its annual surplus back to the university. Cambridge University Press is both the oldest publishing house in the world and the oldest university press and it originated from Letters Patent granted to the University of Cambridge by Henry VIII in 1534, and has been producing books continuously since the first University Press book was printed. Cambridge is one of the two privileged presses, authors published by Cambridge have included John Milton, William Harvey, Isaac Newton, Bertrand Russell, and Stephen Hawking. In 1591, Thomass successor, John Legate, printed the first Cambridge Bible, the London Stationers objected strenuously, claiming that they had the monopoly on Bible printing. The universitys response was to point out the provision in its charter to print all manner of books. In July 1697 the Duke of Somerset made a loan of £200 to the university towards the house and presse and James Halman, Registrary of the University. It was in Bentleys time, in 1698, that a body of scholars was appointed to be responsible to the university for the Presss affairs. The Press Syndicates publishing committee still meets regularly, and its role still includes the review, John Baskerville became University Printer in the mid-eighteenth century. Baskervilles concern was the production of the finest possible books using his own type-design, a technological breakthrough was badly needed, and it came when Lord Stanhope perfected the making of stereotype plates. This involved making a mould of the surface of a page of type. The Press was the first to use this technique, and in 1805 produced the technically successful, under the stewardship of C. J. Clay, who was University Printer from 1854 to 1882, the Press increased the size and scale of its academic and educational publishing operation. An important factor in this increase was the inauguration of its list of schoolbooks, during Clays administration, the Press also undertook a sizable co-publishing venture with Oxford, the Revised Version of the Bible, which was begun in 1870 and completed in 1885. It was Wright who devised the plan for one of the most distinctive Cambridge contributions to publishing—the Cambridge Histories, the Cambridge Modern History was published between 1902 and 1912
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International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
