Mackebrandt, FelixSchuh, Sonja LSilvotti, Roberto2020-11-102020-11-102020Mackebrandt, F. et al. (2020). The EXOTIME project: Signals in the O-C diagrams of the rapidly pulsating subdwarfs DW Lyn, V1636 Ori, QQ Vir, and V541 Hya. Astronomy and Astrophysics,638,A108. Doi: 10.1051/0004-6361/2019371721432-0746http://hdl.handle.net/10566/5398We aim to investigate variations in the arrival time of coherent stellar pulsations due to the light-travel time effect to test for the presence of sub-stellar companions. Those companions are the key to one possible formation scenario of apparently single sub-dwarf B stars. We made use of an extensive set of ground-based observations of the four large amplitude p-mode pulsators DW Lyn, V1636 Ori, QQ Vir, and V541 Hya. Observations of the TESS space telescope are available on two of the targets. The timing method compares the phase of sinusoidal fits to the full multi-epoch light curves with phases from the fit of a number of subsets of the original time seriesenStarsHorizontal branchPlanets and satellitesDetectionAsteroseismologyArticle