  Light curves and periodograms of 160 B stars observed by the TESS space
mission and 29 main-sequence B stars from Kepler and K2 were used to classify
the variability type. There are 114 main-sequence B stars in the TESS sample,
of which 45 are classified as possible rotational variables. This confirms
previous findings that a large fraction (about 40 percent) of A and B stars may
exhibit rotational modulation. Gaia DR2 parallaxes were used to estimate
luminosities, from which the radii and equatorial rotational velocities can be
deduced. It is shown that observed values of the projected rotational
velocities are lower than the estimated equatorial velocities for nearly all
the stars, as they should be if rotation is the cause of the light variation.
We conclude that a large fraction of main-sequence B stars appear to contain
surface features which cannot likely be attributed to abundance patches.
