STUDIES ON THE VARIABLES OF THE ALGOL-TYPE. 51 



The existence of a secondary minimum is possibly sure for 

 nine Algols and besides these, it is suspected for five stars. For 

 a few of the Algols in which the secondary minimum surely 

 takes place, the light-curve of the secondary minimum is almost 

 equal with that of the principal minimum, like X Carina, Y 

 Cygni and others. In some cases, the whole light-curve tends to 

 that of a star wuich belongs to the type of ß Lyrœ. If we include 

 these stars into the type of the Algol, as there is no good reason 

 to divide the variables belonging to the type of ß Lyr^e from the 

 variables of the type of the Algol, the number of the Algols will 

 be increased 10 or more. But here again a similar difficulty 

 will be met with, i.e., to distinguish these ß Lyrae-type variables 

 from those of the short period. 



For five stars belonging to the class of Algols, which show 

 the asymmetrical light-curve, the light-curve is very peculiar, 

 having a secondary unduration near the minimum and these can 

 not be fully explained only by the theory of eclipse. The re- 

 markable stars of this class are S Cancri, and KW Monocerotis 

 and besides these, U Ophiuchi, Y Cygni 21.1210 Andromède also 

 belong to this class. Some observers found such anomalous de- 

 viations in some other stars in certain minima while the mean 

 light-curve shows the ordinary appearence. In such cases, it is 

 rather difficult to decide whether it is only a subjective or at- 

 mospheric phenomenon, or whether such variation of light takes 

 place in stars, themselves. 



Tokyo Astronomical Observatory, Oct. 20, 1910. 



