A Statistical Study of Rotational Broadening in 112 Stars of Class F

The width of the spectral line X 4215 is recorded for 112 stars of class F. A diagram illustrating the frequency of occurrence of different widths among the early and among the late F's shows that appreciable rotation disappears in the middle F's. The frequency diagram for class F is compared with those for classes B and A as determined in pre- vious papers. The indication is that stars of class A have greater velocities of rotation than those of either class B or class F. There is no deftnite relation between absolute magnitude and rotational velocity. The average observed rotational velocity is inde- pendent of galactic latitude, which indicates that the axes of the stars are directed at random