Discovery of TOI-1260d and the characterisation of the multi-planet system

We report the discovery of a third planet transiting the star TOI-1260, previously known to host two transiting sub-Neptune planets with orbital periods of 3.127 and 7.493 days, respectively. The nature of the third transiting planet with a 16.6-day orbit is supported by ground-based follow-up observations, including time-series photometry, high-angular resolution images, spectroscopy, and archival imagery. Precise photometric monitoring with CHEOPS allows to improve the constraints on the parameters of the system, improving our knowledge on their composition. The improved radii of TOI-1260b, TOI-1260c are 2.36±0.06R⊕⁠, 2.82±0.08R⊕⁠, respectively while the newly discovered third planet has a radius of 3.09±0.09R⊕⁠. The radius uncertainties are in the range of 3%, allowing a precise interpretation of the interior structure of the three planets. Our planet interior composition model suggests that all three planets in the TOI-1260 system contains some fraction of gas. The innermost planet TOI-1260b has most likely lost all of its primordial hydrogen-dominated envelope. Planets c and d were also likely to have experienced significant loss of atmospheric through escape, but to a lesser extent compared to planet b.

Citation

Lam , K W F , Cabrera , J , Hooton , M J , Alibert , Y , Bonfanti , A , Beck , M , Deline , A , Florén , H-G , Simon , A E , Fossati , L , Persson , C M , Fridlund , M , Salmon , S , Hoyer , S , Osborn , H P , Wilson , T G , Georgieva , I Y , Nowak , G , Luque , R , Egger , J A , Abidekyan , V , Alonso , R , Escudé , G A , Bárczy , T , Barrado , D , Barros , S C C , Baumjohann , W , Beck , T , Bekkelien , A , Benz , W , Billot , N , Bonfils , X , Brandeker , A , Broeg , C , Charnoz , S , Cameron , A C , Csizmadia , S , Davies , M B , Deleuil , M , Delrez , L , Demangeon , O D S , Demory , B-O , Ehrenreich , D , Erikson , A , Fortier , A , Futyan , D , Gandolfi , D , Gillon , M , Guedel , M , Guterman , P , Laskar , J , Latham , D W , Lecavelier des Etangs , A , Lendl , M , Lovis , C , Heng , K , Isaak , K G , Kiss , L , Magrin , D , Maxted , P F L , Nascimbeni , V , Olofsson , G , Ottensamer , R , Pagano , I , Pallé , E , Peter , G , Piotto , G , Pollacco , D , Queloz , D , Ribas , I , Ragazzoni , R , Rando , N , Rauer , H , Santos , N C , Scandariato , G , Seager , S , Ségransan , D , Serrano , L M , Smith , A M S , Sousa , S G , Steller , M , Szabó , G M , Thomas , N , Udry , S , Van Grootel , V , Walton , N A & Winn , J N 2023 , ' Discovery of TOI-1260d and the characterisation of the multi-planet system ' , Monthly Notices of the Royal Astronomical Society , vol. 519 , no. 1 , stac3639 , pp. 1437–1451 . https://doi.org/10.1093/mnras/stac3639

Publication

Monthly Notices of the Royal Astronomical Society

Status

Peer reviewed

DOI

https://doi.org/10.1093/mnras/stac3639

ISSN

0035-8711

Type

Journal article

Rights

Copyright © 2022 The Author(s) Published by Oxford University Press on behalf of Royal 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/10.1093/mnras/stac3639.

Description

Funding: ACC and TW acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant number ST/R003203/1.

Collections

University of St Andrews Research

URI

http://hdl.handle.net/10023/26671