Some preliminary results of perturbation method applied to 5/2 asteroidal resonance with Jupiter are presented. The results are compared with those obtained by the author with the Wisdom method previously applied to this resonance by Šidlichovský and Melendo. Inferences for the origin of the corresponding Kirkwood gap are drawn.
We present preliminary results from a spectroscopic survey for absorption line profile variations among the O stars. Our data consist of more than 1000 high quality spectra of 46 bright O stars which were obtained with sufficient time resolution to sample variations with timescales of hours to days. Most spectral types and luminosity classes are represented. We find that about 31% of these stars exhibit photospheric variability which probably arises from organized velocity fields. The remaining stars are either constant (31% of the sample) or possess variability associated with their winds (43% of the sample, including 2 of the photospheric variables). We present examples illustrating each of these classes of behaviour, and discuss preliminary implications and future
directions of this work.