626 Tables 807 and 808 



TABLE 807. — Spectrum Class and Proper Motions 



(Reprinted by permission from Russell, Dugan, and Stewart, Astronomy, 

 Ginn & Co., 1927.) 



O 



.10. 

 .20. 



■45- 

 .80. 

 .00. 



Limits of p. m. 



0".00 to 0".02 

 O .02 tO O .04 



o .04 to 

 o .10 to o 



O .20 to 



o .45 to o 



.80 tO 2 



Over 2". 00 



Mean p. m o".22 



Percentage of stars with 

 H > o".2o 



B A F G K M N 



238 392 97 107 2l8 48 3 



164 533 115 91 327 54 4 



88 476 231 168 393 99 2 



160 24s 70 242 27 1 



1 31 168 56 88 8 



1 46 20 23 1 



1 12 19 13 



.... 166.. 



o".03 o".o6 o".i7 o".i8 o".i2 o".o7 o".04 



0.2 5 25' 18 10 4 o 



TABLE 808. — Equipartition of Energy in Stellar Motions 

 (Jeans, Nature, 122, 689, 1928.) 



Type. 



Ao 

 A2 



A 5 

 Fo 



F 5 

 Go 



G 5 

 Ko 

 K 5 



Mo 



" This equality of energy can be attributable only to the gravitational interaction of the 

 stars. For if it were produced by any physical agency, such as pressure of radiation, 

 bombardment by molecules, atoms, or high-speed electrons, this agency, as the last column 

 shows, would have to be in thermodynamical equilibrium with matter at a temperature of 

 the order of 2 X io 02 °K. Since no such temperatures are known the observed equality 

 must be due to gravitational interactions over millions of years. Such evidence suggests 

 a general age of the stars of 5 to 10 million-million years." 



Smithsonian Tables 



