摘要：We report the detection of the first circumbinary planet (CBP) found by Transiting Exoplanet Survey Satellite (TESS).The target, a known eclipsing binary, was observed in sectors 1 through 12 at 30 minute cadence and in sectors 4 through 12 at 2 minute cadence.It consists of two stars with masses of 1.1 M⊙ and 0.3 M⊙ on a slightly eccentric (0.16), 14.6 day orbit, producing prominent primary eclipses and shallow secondary eclipses.The planet has a radius of ~6.9 R⊕ and was observed to make three transits across the primary star of roughly equal depths (~0.2%) but different durations—a common signature of transiting CBPs.Its orbit is nearly circular (e ≈ 0.09) with an orbital period of 95.2 days.The orbital planes of the binary and the planet are aligned to within ~1°.To obtain a complete solution for the system, we combined the TESS photometry with existing ground-based radial-velocity observations in a numerical photometric-dynamical model.The system demonstrates the discovery potential of TESS for CBPs and provides further understanding of the formation and evolution of planets orbiting close binary stars.
