Calculation of Theoretical Rotational Line Profiles for the Determination of V Sin i in the Spectral Range 09-F8

In this paper we present some of the results of an extensive set of model calculations for rotating mainsequence stars in the spectral range O9-F8. Line profiles have been calculated for the lines of He I A4471, Mg ii A4481, and Fe I A4476. It is shown that the helium and iron lines are extremely sensitive to the amount of stellar rotation while the magnesium line is not. This results in some ambiguity in spectral classification for stars in the range 137-139. However, as a result of a corresponding rotational color effect the ambiguity would be very difficult to detect in individual stars. Subject headings: line profiles - rotation, stellar