Skip to main content

Research Repository

Advanced Search

TOI-1338: TESS' First Transiting Circumbinary Planet


TOI-1338: TESS' First Transiting Circumbinary Planet Thumbnail



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.

Acceptance Date Apr 15, 2020
Publication Date May 7, 2020
Journal Astronomical Journal
Print ISSN 0004-6256
Publisher American Astronomical Society
Keywords exoplanet astronomy, eclipsing binary stars
Publisher URL


You might also like

Downloadable Citations