STABS 



STARWORT 



691 



In studying the physical nature of the stars, 

 modern, unlike ancient and mediaeval, science, 

 assuming that the universe is continuous, lias con- 

 sidered the laws governing terrestrial matter to 

 obtain throughout the visible universe. It was 

 therefore easy, once the question of stellar distance 

 was partly answered, to reach the conclusion that 

 the stars are really suns. For they have that in 

 common with pur sun, and even with our caudles, 

 that they emit light, and their light, when ana- 

 lysed, exhibits all the qualities of that emitted by 

 luminous bodies in our laboratories. When their 

 masses are calculated they are found to form bodies 

 of the same order of magnitude as our sun. 

 a Centauri (a 'double') has a mass twice that of 

 the sun. 61 Cygni only equals l the solar mass. 

 Judging not by direct measurement of mass, but 

 by distance and relative brightness, the star Arc- 

 turus is 10,000 times more luminous than our sun, 

 and may have a volume equal to 1,000,000 suns. 

 Other stars, either very brilliant or very distant, 

 range in the same order of magnitude, though 

 too much reliance should not be placed on these 

 calculations, which are liable to large errors and 

 discordances. 



These investigations prepare us to expect that 

 the stars are similar in materials and in history 

 to our own sun. When the spectroscope (see 

 SPECTRUM ) is applied to examine their light this 

 expectation is confirmed. The star Aluebaran 

 hows the spectral lines of hydrogen, sodium, 

 magnesium, iron, tellurium, antimony, calcium, 

 bismuth, and mercury, indicating that these 

 elements exist in its atmosphere in the vaporous 

 state. The examination of numbers of stars con- 

 firms this, so that we know the stars to be of 

 material similar to that composing our earth. 

 The problem before astronomers is therefore now 

 to determine the physical state of the matter 

 composing the stars, and the history of their con- 

 struction. Through Kant and Laplace the idea 

 had become familiar that nebulie and stars repre- 

 sent different stages of star history, and that 

 different stare correspond to different steps in the 

 process of star life, if we may use the expression. 

 Though certainly not yet proved, much of modern 

 discovery confirms this view. There is no distinct 

 line between stars and nebulie. From the cloudy 

 mist of the Orion nebulae to the sparkling point of 

 Vega or Sirius a gradation of forms may be traced 

 wit li no sensible break. 



Rutherfurd of New York, in 1863, first classified 

 the stars according to their spectra into three 

 groups : ( 1 ) Red and golden stars ; (2) white stars 

 with lines in their spectra; (3) white stars (as he 

 supposed) without lines. In 1865 Secchi com- 

 menced also to classify, ultimately adopting a 

 division into four types, which, though alteredby 

 Vogel in name, remains the standard classification 

 of the stars. It is as follows : 



I. Continuous spectrum, with four heavy hydrogen lines. 



Whit* stars, as Sirius and Vega. 

 II. Closely resembling solar spectrum. Yellow stars. Aide- 



baran and our Sun. 



III. Red stars. Fluted bands, fainter towards the violet end. 

 IV. Faint, deep red stars. Fluted bands wider than in III., 



and fading toward* the red. 



Two prominent explanations are given of these 

 types. The first is that they represent the various 

 stages of star history in order, Class I. containing 

 stars newly formed and excessively hot and 

 brilliant, while Class IV. contains stars cooled 

 down nearly to extinction. The other explana- 

 tion, due to Lockyer, is that Class III. represents 

 an earlier stage in star history than either I. or II., 

 showing, in fact, the fainter beginning of stellar 

 luminosity ; while Class IV. represents the closing 

 period of the star's life as it approaches extinction. 

 Lockyer has on these lines attempted a full classi- 



fication of the nebula) and stars, considering all 

 to have their origin in swarms of meteorites (see 

 METEORS), with which he supposes space to be 

 everywhere peopled, and whose collisions, abra- 

 sions, and condensations give us ultimately all 

 celestial bodies. This theory has grave objections, 

 and is certainly not established as fact, but it has 

 the merit of being an attempt to unite a vast 

 variety of stellar phenomena under one intelligible 

 principle. We therefore give Lockyer's develop- 

 ment of Secchi's classes, with his explanations. 



I. Radiation lines and flutings chiefly. Nebulae and stars 



with bright line spectra. 



II. Mixed radiation and absorption chiefly. Bed stars. Bright 

 flutings i.e. bands fading -towards the violet. 



III. Line absorption chiefly. 



IV. Few strong lines. Hottest stars. Central point of star 



life. 



V. Resembling group III. ; but stars cooling. 

 VI. Carbon absorption chiefly. Stars cooling to extinction. 



New stars, on Lockyer's theory, are produced by 

 the sudden collision of swarms of meteors, variable 

 stars by the revolution of two or more swarms, 

 which periodically mingle and collide ; and in 

 other ingenious ways various stellar features are 

 accounted for. Time and future observations must 

 be waited for before these explanations are either 

 wholly accepted or rejected. Other eminent 

 scientists strongly object to Lockyer's conclusions. 

 In particular, Croll contended that all evidence 

 goes to show that the physical universe had a 

 beginning not as scattered meteorites, but as im- 

 mense solid masses moving with a finite velocity, 

 whose collisions formed the first step in the evolu- 

 tion of the various heavenly bodies. Caution in 

 accepting any such theories is, however, very 

 desirable. 



For further information readers may consult G. F. 

 Chambers's Descriptive Astronomy (4th ed. 1889-90, 3 

 vols.); Herschel's Outlines of Astronomy; Miss A. 

 Clarke's History of Astronomy in the 19th Century, and 

 The System of the Stan (1890); Proceedings Royal 

 Society, vol. xliv., No. 266, being the Bakerian Lecture, 

 1885, by Lockyer; and Croll's Stellar Evolution. See 

 also the articles ASTROLOGY, ASTRONOMY, ZODIAC, &c. 



Stars and Stripes. See FLAG, p. 665. 



Star-stone, a kind of Sapphire (q.v.). 



Start Point, a projection of the coast of 

 Devon, 8 miles S. of Dartmouth, forming the 

 south-eastern extremity of the county. It is 

 crowned by a lighthouse (92 feet), whose light, 204 

 feet above high-water, is visible for 20 miles. 



Starvation. See FAST, Vol. IV. p. 559. 



Star wort, or STITCHWORT (Stellaria), a genus 



Greater Stitch wort (Stellaria Holoitea). 

 of plants of the natural order Caryophylleae, having 



