A Correlation Between the Spectroscopic and Dynamical Characteristics of the Late F - and Early G - Type Stars.

Among the giants and dwarfs in the spectral range F5-G5, some stars have systematically weaker lines than others of the same spectral type and luminosity class. On this basis two groups of stars can be distinguished. An examination of the velocity distributions of the two groups shows definite differences. The velocities of the stars with weaker lines have a larger dispersion than those of the stars with stronger lines; the conventional "high-velocity" stars occur only in the weak4ine group. The two types of stars are about equally numerous among the bright northern stars. Stars with velocities less than 70 km/sec are found in both groups.