TOI-1338 : TESS' first transiting circumbinary planet

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.

Citation

Kostov , V B , Orosz , J A , Feinstein , A D , Welsh , W F , Cukier , W , Haghighipour , N , Quarles , B , Martin , D V , Montet , B T , Torres , G , Triaud , A H M J , Barclay , T , Boyd , P , Briceno , C , Cameron , A C , Correia , A C M , Gilbert , E A , Gill , S , Gillon , M , Haqq-Misra , J , Hellier , C , Dressing , C , Fabrycky , D C , Furesz , G , Jenkins , J M , Kane , S R , Kopparapu , R , Hodžić , V K , Latham , D W , Law , N , Levine , A M , Li , G , Lintott , C , Lissauer , J J , Mann , A W , Mazeh , T , Mardling , R , Maxted , P F L , Eisner , N , Pepe , F , Pepper , J , Pollacco , D , Quinn , S N , Quintana , E V , Rowe , J F , Ricker , G , Rose , M E , Seager , S , Santerne , A , Ségransan , D , Short , D R , Smith , J C , Standing , M R , Tokovinin , A , Trifonov , T , Turner , O , Twicken , J D , Udry , S , Vanderspek , R , Winn , J N , Wolf , E T , Ziegler , C , Ansorge , P , Barnet , F , Bergeron , J , Huten , M , Pappa , G & van der Straeten , T 2020 , ' TOI-1338 : TESS' first transiting circumbinary planet ' , Astronomical Journal , vol. 159 , no. 6 , 253 . https://doi.org/10.3847/1538-3881/ab8a48

Publication

Astronomical Journal

Status

Peer reviewed

DOI

https://doi.org/10.3847/1538-3881/ab8a48

ISSN

0004-6256

Type

Journal article

Rights

Copyright © 2020 American Astronomical Society. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at https://doi.org/10.3847/1538-3881/ab8a48

Description

Funding: Funding for the DPAC has been provided by national institutions, in particular, the institutions participating in the Gaia Multilateral Agreement. W.F.W. and J.A.O.thank John Hood Jr. for his generous support of exoplanet research at SDSU. Support was also provided and acknowledged through NASA Habitable Worlds grant 80NSSC17K0741 and NASA XRP grant 80NSSC18K0519. This work is partly supported by NASA Habitable Worlds grant 80NSSC17K0741. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under grant No.(DGE-1746045). A.H.M.J.T. has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 803193/BEBOP) and from a Leverhulme Trust Research Project grant No. RPG-2018-418. A.C. acknowledges support by CFisUC strategic project (UID/FIS/04564/2019).