Analysing the Hipparcos epoch photometry of λ Bootis stars

Abstract

We performed a homogeneous analysis of the available Hipparcos epoch photometry for all members of the LB group. Besides the known δ Scuti like pulsation frequencies, we searched for eclipses due to binarity or rotational induced variability. The already known frequencies of HD 15165 are confirmed with an additional lower single frequency, which might be caused by an accretion episode. But we are not able to rule out a possible aliasing due to the temporal sampling of the data set. Furthermore, three candidates (HD 15759, HD 120500, and HD 149130) for a possible eclipse were detected. Otherwise, the frequency analysis reveals a null result within our strict detection limits.