Observational evidence against differential rotation in F stars

The interaction of stellar rotation with a convective envelope is expected to produce a differential effect in the surface rotation. The sun is the one example of the effect, and for it, the equator rotates 15%-20% faster than do higher latitudes. Such an effect has never been detected in other stars. An investigation is conducted of F stars, taking into account careful measurements of spectral line shapes which, in certain cases, are expected to reflect the characteristics of differential rotation. It is found that the evidence in the line profiles of F stars near or on the main sequence is strongly against the expected differential rotation. In fact, the differential rotation in these stars is apparently very much less than in the sun.