barentsen
commented
6 years ago A new result on the frequency of circumbinary planets was recently published by Asensio-Torres et al using direct imaging: http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1807.08687
Investigating the frequency of planets around binary stars was one of Kepler’s prime mission goals, as binary stars and multi-star systems are common. Although some planets have been found to orbit binary stars (e.g. Kepler-16b, Doyle et al. 2011), only 11 have been discovered so far (Fleming et al. 2018). The identification of planets in binary star systems is challenging because i) their complicated gravitational interactions may lead to irregular orbital periods and ii) the flux from two stars dilutes transits, reducing their depths.
More work is needed to understand our biases and sensitivity of binary star planets and constrain their frequency. We are not currently aware of publications discussing dedicated searches or occurrence rates for planets in multiple systems. This is nevertheless important because a large fraction of the stars in our Galaxy are thought to occur in multiple systems (Duchˆene & Kraus 2013).