DISTANCES OF THE STARS. 



19 j 



It does not in general follow from the results hitherto ob- 

 tained that the brightest stars are likewise the nearest to us. 

 Although the parallax of a Centauri is the greatest of all at 

 present known, on the other hand, Vega Lyrte, Arcturus, and 

 especially Capella, have parallaxes from three to eight times 

 less than a star of the sixth magnitude in Cygnus. More- 

 over, the two stars which after 2151 Puppis and e Indi show 

 the most rapid proper motion, viz., the star just mentioned 

 in the Swan (with an annual motion of 5"- 123), and No. 

 1830 of Groombridge, which in France is called Argelander's 

 star (with an annual motion of 6"- 974), are three and four 

 times more distant from the sun than a Centauri, which has 

 a proper motion of 3" -58. Their volume, mass, intensity of 

 light,* proper motion, and distance from our solar system, 

 stand in various complicated relations to each other. Al- 

 though, therefore, generally speaking, it may be probable that 

 the brightest stars are nearest to us, still there may be cer- 

 tain special very remote stars, whose photospheres and sur- 

 faces, from the nature of their physical constitution, maintain 

 a very intense luminous process. Stars which from their 

 brilliancy we reckon to be of the first magnitude, may be 

 further distant from us than others of the fourth, or even of 

 the sixth magnitude. When we pass by degrees from the 

 consideration of the great starry stratum of which our solar 

 system is a part, to the particular subordinate systems of our 

 planetary world, or to the still lower systems of Jupiter's and 

 Saturn's moons, we perceive central bodies surrounded by 

 masses in which the successive order of magnitude and of in- 

 tensity of the reflected light does not seem to depend on dis- 

 tance. The immediate connection subsisting between our 

 still imperfect knowledge of parallaxes, and our knowledge of 



* On the proportion of the amount of proper motion to the proximity 

 of the brighter stars, see Struve, Stell, compot. Mensuree Aficrom., p 

 clxi?. 



VOL. Ill -I 



