Wilson, Thomas G;
Goffo, Elisa;
Alibert, Yann;
Gandolfi, Davide;
Bonfanti, Andrea;
Persson, Carina M;
Cameron, Andrew Collier;
... Winn, Joshua N; + view all
(2022)
A pair of Sub-Neptunes transiting the bright K-dwarf TOI-1064 characterised with CHEOPS.
Monthly Notices of the Royal Astronomical Society
, 511
(1)
pp. 1043-1071.
10.1093/mnras/stab3799.
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Abstract
We report the discovery and characterization of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in the Transiting Exoplanet Survey Satellite (TESS) photometry. To characterize the system, we performed and retrieved the CHaracterising ExOPlanets Satellite (CHEOPS), TESS, and ground-based photometry, the High Accuracy Radial velocity Planet Searcher (HARPS) high-resolution spectroscopy, and Gemini speckle imaging. We characterize the host star and determine Teff,⋆=4734±67K , R⋆=0.726±0.007R⊙ , and M⋆=0.748±0.032M⊙ . We present a novel detrending method based on point spread function shape-change modelling and demonstrate its suitability to correct flux variations in CHEOPS data. We confirm the planetary nature of both bodies and find that TOI-1064 b has an orbital period of Pb = 6.44387 ± 0.00003 d, a radius of Rb = 2.59 ± 0.04 R⊕, and a mass of Mb=13.5+1.7−1.8 M⊕, whilst TOI-1064 c has an orbital period of Pc=12.22657+0.00005−0.00004 d, a radius of Rc = 2.65 ± 0.04 R⊕, and a 3σ upper mass limit of 8.5 M⊕. From the high-precision photometry we obtain radius uncertainties of ∼1.6 per cent, allowing us to conduct internal structure and atmospheric escape modelling. TOI-1064 b is one of the densest, well-characterized sub-Neptunes, with a tenuous atmosphere that can be explained by the loss of a primordial envelope following migration through the protoplanetary disc. It is likely that TOI-1064 c has an extended atmosphere due to the tentative low density, however further radial velocities are needed to confirm this scenario and the similar radii, different masses nature of this system. The high-precision data and modelling of TOI-1064 b are important for planets in this region of mass–radius space, and it allow us to identify a trend in bulk density–stellar metallicity for massive sub-Neptunes that may hint at the formation of this population of planets.
| Type: | Article |
|---|---|
| Title: | A pair of Sub-Neptunes transiting the bright K-dwarf TOI-1064 characterised with CHEOPS |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stab3799 |
| Publisher version: | http://dx.doi.org/10.1093/mnras/stab3799 |
| Language: | English |
| Additional information: | © The Author(s) 2022. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | techniques: photometric, techniques: radial velocities, planets and satellites: composition, planets and satellites: detection, planets and satellites: interiors, stars: individual: TOI-1064 (TIC 79748331, Gaia EDR3 6683371847364921088) |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10143214 |
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