Stellar velocity distribution 



13 



The following schemes now give the denominations of the systems as well as 

 the direction cosines between their axes. 





X" 



Y" 



Z" 





X" 



Y" 



Z" 



X 



Tu 



Tai 



Ys. 



X' 



J ll 





= 31 



K s : Y 



Tis 



T 22 



T32 



K x : Y 



e J2 



=22 



"32 



Z 



Tis 



Ï28 



T33 



Z' 



~13 



-23 



SS 



For the rest I refer to the memoir of Charlier. 



9. The new directions of the X and Y axes will naturally only change the corres- 

 ponding direction cosines regarding their signs. I will however reprint these direction 

 cosines of K s relative K 2 after the correction (see table I). 



Determination of the direction and the magnitude of the relative motion 

 of the sun from radial velocity observations. 



10. There are, as well known, amongst the radial velocity determinations 

 several stars whose velocities are exceptionally large. These are chiefly to be found 

 amongst the so called later types. The presence of a large number of such stars 

 may perhaps partly be explained by the circumstances, which make it possible to 

 get good values by measuring the displacements of the spectral lines on the photo- 

 graphic plates. Particularly amongst the faint stars, a large displacement is more easy 

 to discover and determine than a small one, and moreover for stars of types, whose 

 spectra contain a large number of lines, the velocity determination will be more 

 easy than for stars of other types. 



It is, however, necessary in a statistical investigation like this to reject very 

 large velocities, while their influence by the method of moments will be ton great. 

 I have, however, striven to reject as few stars as possible. From a preliminary 

 examination of the velocity distribution, I found it convenient to reject those stars, 

 as whose velocities exceed 14 Siriometer per Stellar year or 66.3 km per second. 



The stars in such way rejected seem chiefly to belong to the fainter magnitudes. 

 A brief computation gives the following distribution of the large velocities. 



Ead. velocity Number of stars Total number 



magn. < 4.9 magn. > 5.0 



p<14.oSm/St 1115 481 1596 



p>14.o » 16 28 44 



Stars with large velocity 



in per cent 1.41 5.60 2.68 



