William Herschel( The founder of stellar astronomy.)
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Biography William Herschel
(November 15, 1738 - August 25, 1822)
The founder of stellar astronomy. Musician, along with the study of theory of music, studied mathematics, astronomy, optics and then. He opened a large number of nebulae, star clusters. Built the first model of the Galaxy, established the movement of the solar system and pointed his direction.
At the turn of the XVII and XVIII centuries, astronomy was limited knowledge about the solar system. On the nature of stars, the distances between them, their distribution in space, nothing was known. The first attempts to penetrate deeper into the mystery of the structure of the stellar universe through careful observation by perhaps more powerful telescopes are linked with the name of the astronomer Herschel.
. Friedrich Wilhelm Herschel was born on November 15, 1738 in Hanover in the family oboist Hanover Guard Isaac Herschel and Anna Ilse Moritz
. Protestants Herschel came from Moravia, which had left, probably because of religious considerations. The atmosphere of the parental home can be called intellectual. 'Biographical Note', Journal and Letters of William, the memories of his younger sister Caroline bring us into the house and world interests Herschel and show that a truly titanic work and dedication, have created an outstanding observer and researcher. He received extensive, but non-systematic education. Classes in mathematics, astronomy, philosophy revealed its ability to exact sciences. But besides this, William had a great musical talent and at fourteen became a musician in the regimental band. In 1757, after four years of military service, he went to England, where several earlier moved his brother James, conductor Hanover Regiment.
. Without a penny in his pocket, William, renamed in England, William, engaged in London's correspondence notes
. In 1766 he moved to Bath, which soon attained great fame as a performer, conductor and music teacher. But such a life could not fully satisfy its. Herschel interest to science and philosophy, the constant self-education led to his passion for astronomy. "What a pity that music is not a hundred times more difficult for science, I love action and I need to exercise," - he wrote to his brother.
In 1773, Herschel became a series of works on optics and astronomy. "A complete system of optics" Smith and "Astronomy" Ferposona have eцёц╝ reference books. In the same year he first looked at the sky through a small telescope with a focal length of about 75 cm, but observations with such a small increase was not satisfied with the researcher. Because the money to buy a wide-aperture telescope was not, he decided to do it myself. Having bought the necessary tools and the workpiece, it is self-molded and polished mirror for his first telescope. Overcome great difficulties, Herschel in the same in 1773 produced a reflector with a focal length of more than 1,5 m. Herschel mirror polishing by hand (the machine for this purpose he founded only fifteen years old), often working on 10, 12 and even 16 hours straight, because stopping the process of grinding affects the quality of mirrors. The work was not only difficult but dangerous, once in the manufacture of blanks for the mirror furnace exploded.
Sister Caroline and brother Alexander were loyal and patient aides, William at this difficult work. His diligence and enthusiasm have given excellent results. Mirrors, Herschel made from an alloy of copper and tin, were of excellent quality and gave perfectly round images of stars.
As wrote the famous American astronomer H. Whitney, from 1773 to 1782 years, Herschel was engaged in what became of professional musicians in the professional astronomers.
In 1775, Herschel began his first "view of the sky". At this time he has continued to earn a living musical activity, but his true passion began to astronomical observations. In between music lessons and he was involved in the manufacture of mirrors for telescopes, giving concerts in the evenings, and nights spent in the star. For this purpose, Herschel suggested an original new way to "Star cherpkov, t. e. counting the number of stars in certain areas of the sky.
. March 13, 1781, during observations, Herschel noticed something unusual: "Between ten and eleven o'clock at night, when I studied the faint stars in the neighborhood of H Geminorum, I noticed one that looked better than the rest
. Surprised by its unusual size, I compared it to H Geminorum and the small star in the square between the constellations Auriga and Gemini, and found that it is much more than any of them. I suspect that it is - a comet ". The object had a pronounced drive and moved along the ecliptic. Informing other astronomers about the opening of the "comet", Herschel continued to observe its. A few months later, two prominent scientists - St. Petersburg Academy of Sciences AI. Leksel and academician of the Paris Academy of Sciences P. Laplace, - calculating the orbit of a celestial object open, proved that Herschel discovered the planet, which is located behind Saturn. The planet later named Uranus, defended from the sun by nearly 3 billion miles and exceeded the volume of the Earth more than 60 times. For the first time in the history of science has discovered a new planet, as the previously known five planets have always been observed in the sky. Opening Uranus extended the borders of the solar system more than doubled and brought glory to its discoverer.
. Nine months after the discovery of Uranus, . December 7, 1781, . Herschel was elected a member of the London Royal Astronomical Society, . he was awarded a doctorate from Oxford University and the Gold Medal of the Royal Society of London (in 1789 St. Petersburg Academy of Sciences elected him an honorary member).,
. Opening career Herschel identified Uranus
. King George III, himself a lover of astronomy and patron gannovertsev, appointed him in 1782, "Astronomer Royal" with an annual salary of 200 pounds. The king also gave him the means to build a separate observatory in Slough, near Windsor. Here Herschel with youthful ardor and extraordinary persistence set to astronomical observations. According to biographer Arago, he came out of the observatory only in order to represent the Royal Society the results of his tireless labor.
Emphasis Herschel continued to give the improvement of telescopes. It is used until the second horizon glass and tossed it does so significantly increased the brightness of the image. Herschel Gradually increase the diameter of the mirrors. His top was built in 1789, a giant telescope on the time, the tube length of 12 m and mirror diameter of 122 cm. This telescope has remained unsurpassed until 1845, when the Irish astronomer in. Parsons to build more telescopes - a length of almost 18 meters with a mirror diameter of 183 cm
With the latest telescope Herschel discovered two satellites of Uranus and two of Saturn's. Thus, with the name of Herschel's discovery of several related celestial bodies in the solar system. But that's not the main value of his remarkable work.
And so Herschel was aware of several tens of double stars. But these stellar pairs were considered as random convergence of their constituent stars, and not assumed that binary stars are common in the universe. Herschel carefully studied different parts of the sky for many years and opened more than 400 double stars. He studied the distance between the components (in angular measures), their color and apparent brightness. In some cases, the stars, previously considered a double, triple and quadruple proved (multiple stars). Herschel came to the conclusion that double and multiple star - a system of stars that are physically connected to each other and, as he found circulating around a common center of gravity, according to the law of universal gravitation. Herschel was the first in the history of science, astronomer, has systematically studied the double stars. Since ancient times were known bright nebula in the constellation Orion and the nebula in the constellation Andromeda, visible to the naked eye. But only in the XVIII century by the perfection of telescopes was discovered many of the nebulae. Kant and Lambert felt that the nebula - this entire star systems, and other Milky Way, but deleted the enormous distances, which can not be distinguished individual stars.
. Herschel has done a great job, opening and exploring new nebula
. He used all the increasing strength of its telescopes. Suffice it to say that he had compiled on the basis of his observations catalogs, the first of which appeared in 1786 amounted to about 2,500 nebulae. The task of Herschel, however, was not just finding the nebulae, and the disclosure of their nature. In his powerful telescopes, many of the nebula is clearly divided into individual stars and turned out thus far from the solar system star cluster. In some cases, provided the nebula star, surrounded by a hazy ring. But other nebulae were not divided up at the stars, even with the most powerful - 122-centimeter telescope.
. First Herschel concluded that almost all nebulae are in fact collections of stars and the most distant of them also lay at the stars in the future - when observed in an even more powerful telescopes
. But he conceded that some of these nebulae are not star clusters within the Milky Way, a separate star system. Further investigation led Herschel to deepen and supplement their views. World nebula is more complex and diverse, whose earlier it could have been anticipated.
. Continuing tirelessly to observe and reflect, Herschel recognized that many of the observed nebulae are in general not be decomposed into a star, because they consist of much more dilute the substance ( "glowing liquid", as Herschel thought) than the stars.
. Thus, Herschel came to the conclusion that misty stuff, like a star, is widespread in the universe
. The question naturally arises about the role of this substance in the universe, about whether it is material from which emerged the star. Even in 1755 and. Kant put forward a hypothesis on the formation of entire star systems out of the original diffuse material. Herschel made a bold idea that different types of indecomposable nebulae represent different stages of star formation. By sealing the nebula from it gradually formed a whole cluster of stars or one star, which in the beginning of its existence, yet surrounded by hazy shell. If Kant believed that all the stars of the Milky Way once formed simultaneously, Herschel first suggested that stars have different ages and star formation continues without interruption, it's happening in our time.
. This idea Herschel was then forgotten, and a mistaken view of the origin of one-time all-star in the distant past, long dominant in science
. Only in the second half of XX century on the basis of the enormous success of astronomy and in particular the works of Soviet scientists found a difference of age stars. Study whole classes of stars, no doubt a few of the existing millions of years, unlike other stars whose age is determined by the billions of years,. Herschel's views on the nature of the nebulae in general terms, confirmed by modern science, which established that the gas and dust nebulae are common in our and other galaxies. The nature of these nebulae proved more difficult than it might involve Herschel.
. However, Herschel and at the end of life he was convinced that some nebulae are distant star systems, which will eventually be placed on individual stars
. And in this he, like Kant and Lambert, he was right.
As already mentioned, in the XVIII century it was discovered the proper motion of many stars. Herschel by calculation succeeded in 1783 conclusively proved that our solar system is moving toward the constellation of Hercules.
. But its main task Herschel to clarify the structure of the stellar system, the Milky Way, or our galaxy, its shape and size
. This he worked for several decades. In his possession was not then the data either on the distances between stars, not on their placement in space, nor on their sizes and luminosities. Without these data, Herschel assumed that all stars have the same luminosity and uniformly distributed in space, so that the distance between them is more or less the same, but the sun is near the center of the system. It Herschel did not know the phenomenon of absorption of light in world space and thought, moreover, that his giant telescope available, and even the most distant stars of the Milky Way. With this telescope he counted stars in different parts of the sky and tried to determine how far in either direction extends our star system.
But the assumptions were wrong Herschel. We now know that stars differ in luminosity and that they are distributed unevenly in the Galaxy. The galaxy is so large that its boundaries were not available even a giant telescope, Herschel. Therefore he could not come to correct conclusions about the shape of the Galaxy and the situation in her Sun, and the size of it is very understated.
Herschel was engaged in other matters of astronomy. Incidentally, he unraveled the complex nature of solar radiation and concluded that part of it includes light, heat and chemical rays (radiation is not perceived by the eye). In other words, Herschel anticipated opening of the rays beyond the ordinary solar spectrum - infrared and ultraviolet.
. Herschel began his scientific career as a humble fan, who had an opportunity to devote astronomy only their spare time
. Teaching music for a long time remained for him a source of livelihood. Only in old age he acquired the material opportunities for practicing science.
It combines the features of this scientist and wonderful person. Herschel was a skilled observer, an energetic explorer, deep thinker and committed. At the very zenith of his fame, he remained a charismatic, kind and simple man, which is characteristic of a deep and noble nature.
His passion for astronomy, Herschel was able to pass on to their families and friends. His sister Caroline, as already mentioned, helped him in many scientific papers. Having studied under the guidance of his brother in mathematics and astronomy, Carolina handled independently of its observation, prepared to publish catalogs of nebulae and star clusters Herschel. A lot of time to dedicate observations, Carolina has opened 8 new comets and 14 nebulae. She was the first woman researcher, adopted on an equal footing in a cohort of British and European astronomers, who elected her an honorary member of the London Royal Astronomical Society and the Royal Irish Academy.
. In 1788, Herschel married an Englishwoman, Mary Pitt
. Their son John, born in Slough in 1792, already in childhood discovered the remarkable ability. He became one of the most famous British astronomers and physicists of the XIX century. His popular book "Essays on Astronomy" has been translated into Russian and has played a big role in the dissemination of astronomical knowledge in Russia.
William Herschel died August 25, 1822 and is buried in a small church near Windsor.