TOI-1338: TESS' First Transiting Circumbinary Planet


The extent of the system HZ, calculated based on the properties shown in Table 4. The conservative HZ is shown in dark green and the optimistic extension to the HZ is shown in light green. The known planet is substantially interior to the boundaries of the system HZ and close to the stability boundary.

We report the detection of the first circumbinary planet found by 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 two-minute cadence.


It consists of two stars with masses of 1.1 MSun and 0.3 MSun 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 REarth 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 circumbinary planets. 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 degree.

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 circumbinary planets, and provides further understanding of the formation and evolution of planets orbiting close binary stars.

Veselin B. Kostov, Jerome A. Orosz, Adina D. Feinstein, William F. Welsh, Wolf Cukier, Nader Haghighipour, Billy Quarles, David V. Martin, Benjamin T. Montet, Guillermo Torres, Amaury H.M.J. Triaud, Thomas Barclay, Patricia Boyd, Cesar Briceno, Andrew Collier Cameron, Alexandre C.M. Correia, Emily A. Gilbert, Samuel Gill, Michael Gillon, Jacob Haqq-Misra, Coel Hellier, Courtney Dressing, Daniel C. Fabrycky, Gabor Furesz, Jon Jenkins, Stephen R. Kane, Ravi Kopparapu, Vedad Kunovac Hodzic, David W. Latham, Nicholas Law, Alan M. Levine, Gongjie Li, Chris Lintott, Jack J. Lissauer, Andrew W. Mann, Tsevi Mazeh, Rosemary Mardling, Pierre F.L. Maxted, Nora Eisner, Francesco Pepe, Joshua Pepper, Don Pollacco, Samuel N. Quinn, Elisa V. Quintana, Jason F. Rowe, George Ricker, Mark E. Rose, Sara Seager, Alexandre Santerne, Damien Segransan, Donald R. Short, Jeffrey C. Smith, Matthew R. Standing, Andrei Tokovinin, Trifon Trifonov, Oliver Turner, Joseph D. Twicken, Stephane Udry, Roland Vanderspek, Joshua N. Winn, Eric T. Wolf, Carl Ziegler, Peter Ansorge, Frank Barnet, Joel Bergeron, Marc Huten, Giuseppe Pappa, Timo van der Straeten

Comments: 35 pages, 21 figures, 6 tables
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2004.07783 [astro-ph.EP] (or arXiv:2004.07783v1 [astro-ph.EP] for this version)
Submission history
From: Veselin Kostov B
[v1] Thu, 16 Apr 2020 17:25:08 UTC (9,310 KB)
https://arxiv.org/abs/2004.07783
Astrobiology, exoplanet

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