BEBOP is a radial-velocity survey that monitors a sample of single-lined eclipsing binaries, in search of circumbinary planets by using high-resolution spectrographs. Here, we describe and test the methods we use to identify planetary signals within the BEBOP data, and establish how we quantify our sensitivity to circumbinary planets by producing detection limits. This process is made easier and more robust by using a diffusive nested sampler. In the process of testing our methods, we notice that contrary to popular wisdom, assuming circular orbits in calculating detection limits for a radial velocity survey provides over-optimistic detection limits by up to 40% in semi-amplitude with implications for all radial-velocity surveys. We perform example analyses using three BEBOP targets from our Southern HARPS survey. We demonstrate for the first time a repeated ability to reach a residual root mean squared scatter of 3m.s−1 (after removing the binary signal), and find we are sensitive to circumbinary planets with masses down to that of Neptune and Saturn, for orbital periods up to 1000days.
@article{arxiv.2112.05652,
title = {BEBOP II: Sensitivity to sub-Saturn circumbinary planets using radial-velocities},
author = {Matthew R. Standing and Amaury H. M. J. Triaud and João P. Faria and David V. Martin and Isabelle Boisse and Alexandre C. M. Correia and Magali Deleuil and Georgina Dransfield and Michaël Gillon and Guillaume Hébrard and Coel Hellier and Vedad Kunovac and Pierre F. L. Maxted and Rosemary Mardling and Alexandre Santerne and Lalitha Sairam and Stéphane Udry},
journal= {arXiv preprint arXiv:2112.05652},
year = {2022}
}