The BEBOP (Binaries Escorted By Orbiting Planets) survey is a search for circumbinary planets using the radial velocity spectrographs HARPS and SOPHIE, currently focusing on single-lined binaries with a mass ratio < 0.3. Circumbinary systems are an important testing ground for planet formation theories as the dynamically complex influence of the binary makes planet formation and survival more difficult. Here we present the results of the survey so far including: confirmed planets such as BEBOP-1c the first circumbinary planet detected in radial velocity; the status of our observations; and preliminary occurrence rates. We compare the early results of the radial velocity survey to the population of circumbinary planets discovered in transit, and suggest that there may be a population of inflated planets close to the inner binary which are detectable in transit but more difficult in radial velocity. Using time-lag tidal theory, we show that this inflation is unlikely caused by tides.

It is shown that W UMa-type and SX Phe-type stellar populations are both perfectly and uniquely suited for maintaining hyper-effective biopolymer chain reactions (BCR) on their planets once the planet is in the stellar habitable zone. W UMa-type stars are known to be contact binaries, and SX Phe-type stars are presumably post-binaries, i.e., products of stellar mergers. In case of the contact binaries, the eclipse-driven periodic heating/cooling of planetary surfaces has period-amplitude parameters that perfectly satisfy stringent conditions for maintaining BCR-like reactions. In case of the post-binaries, the stars pulsate with periods and amplitudes also perfectly suited for maintaining the reactions. Therefore, the ‘W UMa – SX Phe’ metamorphosis (from a contact binary to a post-binary, via the merger) seems to provide a potential biosystem reboot on planets in these systems.