The Occurrence of Circumbinary Planets Around TESS M-dwarf Eclipsing Binaries

We present the first determination of the occurrence of transiting circumbinary planets (CBPs) in TESS data. Since tight binaries represent a constrained environment relative to single stars, CBPs contribute to our understanding of planet formation and evolution. We applied our custom single-transit detection algorithm to the recently-published sample of TESS eclipsing binaries containing two M-dwarfs (M&Ms), finding only one signal attributable to a new candidate planet-sized object. We further performed sensitivity analysis and applied corrections to account for the TESS window function to arrive at our survey completeness. We find a 95% confidence level (CL) upper limit on the occurrence rate of coplanar CBPs with sizes in the range 2-16 R and with orbital periods up to 600 days of 33.0%. If the mutual inclinations of CBPs are isotropically distributed with respect to the binaries, the occurrence rate upper limit increases to 40.2%. Our occurrence rate estimates are limited in part by the misalignment of our short-period binaries relative to the line of sight.