647 



SCIENTIFIC SIDE-LIGHTS 



Star 

 Stars 



3201. STAR-COLORS REAL Spec- 

 trum Analysis of Double Stars. Spectrum 

 analysis applied to the double stars has 

 proved that the beautiful colors presented 

 by these pairs are not due to the simple 

 effect of contrast, but are real. The two 

 suns which compose the double star ft of 

 Cygnus, one colored yellow and the other 

 blue, show two spectra absolutely different. 

 A similar observation, made on the two com- 

 ponents of a Herculis, of which one is orange- 

 colored and the other bluish green, has also 

 shown spectra totally different. In each of 

 these two cases the special color of each star 

 agrees with the way in which the light is 

 distributed in the different regions of its 

 spectrum. FLAMMARION Popular Astrono- 

 my, bk. vi, ch. 6, p. 612. (A.) 



3202. STAR-DRIFTING Sets of Stars 

 that Travel as Systems through Space 

 Ursa Major Proctor's Prediction Veri- 

 fied. I have said that my object was to 

 determine whether any set of stars show a 

 tendency to drift together. ... I predict- 

 ed that whenever Dr. Huggins should apply 

 to them [five specified stars of Ursa Major] 

 the new spectroscopic method he would find 

 that they were either all approaching or all 

 receding, and at a common rate. 



This prediction was exactly confirmed by 

 the event two years later. It happened that 

 Dr. Huggins had forgotten which of the 

 seven stars form the drifting set of five. 

 He proceeded, however, with his observa- 

 tions. He found both the remaining wheel- 

 stars receding at the rate of about twenty 

 miles per second. The star representing 

 the first horse was found to be receding 

 at the same rate, and lastly the star repre- 

 senting the second horse. Here, then, were 

 five stars receding at the rate of about 

 twenty miles per second; but Dr. Huggins 

 supposed at the moment that these were 

 not the five stars respecting which I had 

 made my little prediction. On turning, how- 

 ever, to my " Other Worlds " ( published 

 two years before his observations were 

 made), he found that it was the set of five 

 stars which he had found to be thus re- 

 ceding at a common rate which I had de- 

 scribed as, in my belief, forming a drifting 

 set. I think the inference is fair that my 

 general theory respecting local star-drifts is 

 correct, and that among those stars which 

 form our familiar systems there are groups 

 traveling as systems through space. PROC- 

 TOR Expanse of Heaven, p. 294. (L. G. & 

 Co., 1897.) 



3203. STARS AND NEBULJE Neb- 

 ulous Masses Intermixed icith Stars. Some 

 important points in cosmical economy have, 

 indeed, become quite clear within the last 

 thirty years, and scarcely any longer ad- 

 mit of a difference of opinion. One of these 

 is that of the true status of nebulae. This 

 was virtually settled by Sir J. HerschePs 

 description in 1847 of the structure of the 

 Magellanic clouds; but it was not until 



Whewell in 1853, and Herbert Spencer in 

 1858, enforced the conclusions necessarily 

 to be derived therefrom, that the conception 

 of the nebulae as remote galaxies, which 

 Lord Rosse's resolution of many into stellar 

 points had appeared to support, began to 

 withdraw into the region of discarded and 

 half-forgotten speculations. In the nubecu- 

 lae as Whewell insisted " there coexists in 

 a limited compass and in indiscriminate po- 

 sition stars, clusters of stars, nebulae regular 

 and irregular, and nebulous streaks and 

 patches. These, then, are different kinds of 

 things in themselves, not merely different 

 to us. There are such things as nebulae side 

 by side with stars and with clusters of stars. 

 Nebulous matter resolvable occurs close to 

 nebulous matter irresolvable." CLERKE His- 

 tory of Astronomy, pt. ii, ch. 12, p. 505. 

 (BL, 1893.) 



3204. STARS, A SEED-PLOT OF 



Our Sun a Star of the Milky Way. This 

 seed-plot of stars [the Milky \Vay] is 

 formed of objects individually invisible to 

 the naked eye below the sixth magnitude, 

 but so crowded that they appear to touch 

 each other and form a nebulous gleam which 

 all human eyes directed to the sky for 

 thousands of years have contemplated and 

 admired. Since it is developed like a girdle 

 round the whole circuit of the sky, we our- 

 selves must be in the Milky Way. The first 

 fact which impresses our minds is that our 

 sun is a star of the Milky Way. FLAM- 

 MARION Popular Astronomy, bk. vi, ch. 10, 

 p. 654. (A.) 



3205. STARS, COUNTING OF Seven 

 Thousand Visible to Naked Eye. According 

 to this estimation, the number of stars of 

 the first six magnitudes, or, in other words, 

 the total number visible to the naked eye, 

 is about 7,000. Excellent sight distinguishes 

 8,000, average sight about 5,700. Generally, 

 we think we see many more; we believe we 

 can count them by myriads, by millions; 

 in this, as in other things, we are always 

 led into exaggeration. As a matter of fact, 

 however, the number of stars visible to the 

 naked eye in both hemispheres all over the 

 earth does not exceed the above figures. 

 The stars visible to the naked eye for or- 

 dinary sight are in reality so few in num- 

 ber that we might easily show them in an 

 illustration of the size of these pages, and 

 count them: the southern hemisphere has 

 3,307, and the northern 2,478; total, 5,785, 

 without counting, of course, the star-dust 

 of the Milky W r ay. Thus we see with the 

 naked eye fewer stars in the sky than there 

 are inhabitants in a small town. It is, then, 

 not so difficult to make their acquaintance 

 as might be imagined. It is but an hour's 

 amusement. FLAMMARION Popular Astron- 

 omy, bk. vi, ch. 4, p. 586. (A.) 



3206. STARS, DOUBLE, EFFECT OF 



Quadruple Alternation of Day and Night 

 Our Experience Not the Limit. Every one 



