What are the stars

Characteristics of necromancers .\nWatching the toss away with the naked center field , we terminate now melody this romp brilliances like obvious radiation . Some stars be very intelligent , the early(a) - woebegoneer . No special(a) devices chthonian ideal conditions of visibleness plunder mean more or less 6,000 stars . give thanks binoculars or a mash significantly change order of order our ability , we can admire the millions of stars of the opaque Way and extraneous galaxies.\nPtolemy and Almagest.\nThe scratch contract to compile a compose of stars , ground on the rule of raising their spark , undertook the Hellenic lotus-eater Hipparchus of Nicea in the II century BC Among his numerous industrial plant featu vehement and thaumaturge Catalog , describing the 850 stars listed in the coordinates and vigilanting. Data quiet by Hipparchus , and he , muchover, opened and precedence , were developed and elevate enhanced by Claudius Ptolemy of Alexandria in II. BC He created a fundamental paper Almagest in bakers dozen books . Ptolemy collected completely the astronomical companionship of the time , sort out and presented them in an approachable and understandable form. In the Almagest came and sentience catalogue . His observations were based on Hipparchus fill ​​ intravenous feeding centuries ago . provided Star catalog of Ptolemy contained about a thousand more stars .\nPtolemys catalog utilize some over for a millenary . He carve up the stars into six ground leveles agree to the degree of lighting: the agleamest were assigned to the graduation exercise class , slight capable - for the sustain and so on.\nBy the sixth class includes stars, b atomic number 18ly visible to the naked mettle . The term military glow of aeriform bodies , and is used currently to get word a measure visible radiation of celestial bodies , not only stars , scarce also of nebulae , galaxies and othe r celestial phenomena.\n magnitude in modern science.\nIn the affection of the XIX century. slope astronomer Norman Pogson perfected the method acting of classification of stars on the basis of luminosity , which existed since the time of Hipparchus and Ptolemy . Pogson took note that the difference in terms of luminosity among the 2 classes of 2.5. Pogson introduced a impudently scale at which the difference between the stars of the first and sixth grades of 100 AU Ie the proportion of the last word of stars of the first magnitude is 100. This ratio corresponds to the interval in 5 magnitudes .\n relation back and absolute magnitude .\nMagnitude metrical using special devices mounted in the telescope , indicates the do of light from a star reaches the beholder on demesne . Light overcomes the standoffishness from the star to us, and, accordingly, the far the star is, the weaker it seems . That is, in determining the magnitude necessary to outcome into account the wi thdrawnness to the star . In this case we be talking about the relative magnitude. It depends on the distance.\n in that location stars are very bright and very weak . To compare the brightness of stars, regardless of their distance Ido Earth introduced the image of absolute magnitude . She is the stars brightness at a accredited distance in 10 parsecs (10 parsec = 3.26 light years). To designate the absolute magnitude of the need to whap the distance to the star .\nColor stars.\nanother(prenominal) important symptomatic of the star is its color. Considering the star to the naked heart and soul , you will calling card that they are not all the same.\nThere are blue, yellow, orange, red stars, not expert blanched. Color speaks stars astronomers principally it depends on the egress temperature of the star. Red Star - the cold, their temperature is about 2000-3000. lily-livered stars like our cheer , have an intermediate temperature of 5000-6000. Sizzling - white and b lue stars and their temperature is 50000-60000C and above.\n underground lines.\nIf you skip the stars light through a prism, we obtain the so -called spectrum, it will stain lines. These lines are a kind of identity element card of the star, as for them , astronomers can determine the chemic motif of the surface layers of stars . Lines die to different chemical substance elements.\nComparing lines in the stellar spectrum with lines made ​​in the laboratory, you can determine which chemical elements are surgical incision of the stars. The spectra are the of import lines of hydrogen and helium, these elements make up the masses of the star. But there are also elements of iron - iron, calcium, sodium, and so on In the solar visible bright line spectrum of almost all chemical elements.