Issue |
A&A
Volume 686, June 2024
|
|
---|---|---|
Article Number | A282 | |
Number of page(s) | 16 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202347759 | |
Published online | 21 June 2024 |
Precise characterisation of HD 15337 with CHEOPS: A laboratory for planet formation and evolution★,★★,★★★
1
Instituto de Astrofisica e Ciencias do Espaco, Universidade do Porto, CAUP,
Rua das Estrelas,
4150-762
Porto,
Portugal
e-mail: nuno.rosario@astro.up.pt
2
Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto,
Rua do Campo Alegre,
4169-007
Porto,
Portugal
3
Dipartimento di Fisica, Università degli Studi di Torino,
Via Pietro Giuria 1,
10125,
Torino,
Italy
4
Physikalisches Institut, University of Bern,
Gesellschaftsstrasse 6,
3012
Bern,
Switzerland
5
Center for Space and Habitability, University of Bern,
Gesellschaftsstrasse 6,
3012
Bern,
Switzerland
6
Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology,
Cambridge,
MA
02139,
USA
7
Observatoire Astronomique de l'Université de Genève,
Chemin Pegasi 51,
1290
Versoix,
Switzerland
8
Department of Astronomy, Stockholm University, AlbaNova University Center,
10691
Stockholm,
Sweden
9
Aix-Marseille Univ., CNRS, CNES, LAM,
38 rue Frédéric Joliot-Curie,
13388
Marseille,
France
10
Division Technique INSU,
CS20330,
83507 La
Seyne-sur-Mer cedex,
France
11
Centre for Exoplanet Science, SUPA School of Physics and Astronomy, University of St Andrews,
North Haugh,
St Andrews
KY16 9SS,
UK
12
Space Research Institute, Austrian Academy of Sciences,
Schmiedl-strasse 6,
A-8042
Graz,
Austria
13
Cavendish Laboratory,
JJ Thomson Avenue,
Cambridge
CB3 0HE,
UK
14
Astrobiology Research Unit, Université de Liège,
Allée du 6 Août 19C,
4000
Liège,
Belgium
15
Space sciences, Technologies and Astrophysics Research (STAR) Institute, Université de Liège,
Allée du 6 Août 19C,
4000
Liège,
Belgium
16
Instituto de Astrofisica de Canarias,
Via Lactea s/n,
38200 La
Laguna,
Tenerife,
Spain
17
Departamento de Astrofisica, Universidad de La Laguna,
Astrofísico Francisco Sanchez s/n,
38206 La
Laguna,
Tenerife,
Spain
18
Institut de Ciencies de l’Espai (ICE, CSIC),
Campus UAB, Can Magrans s/n,
08193
Bellaterra,
Spain
19
Institut d’Estudis Espacials de Catalunya (IEEC),
Gran Capità 2-4,
08034
Barcelona,
Spain
20
European Space Agency (ESA), European Space Research and Technology Centre (ESTEC),
Keplerlaan 1,
2201 AZ
Noordwijk,
The Netherlands
21
Admatis,
5. Kandó Kálmán Street,
3534
Miskolc,
Hungary
22
Depto. de Astrofisica, Centro de Astrobiologia (CSIC-INTA),
ESAC campus,
28692
Villanueva de la Cañada (Madrid),
Spain
23
Sub-department of Astrophysics, Department of Physics, University of Oxford,
Oxford
OX1 3RH,
UK
24
Max Planck Institut für Extraterrestrische Physik,
Gießenbachstraße 1,
85748
Garching bei München,
Germany
25
INAF, Osservatorio Astronomico di Padova,
Vicolo dell’Osservatorio 5,
35122
Padova,
Italy
26
Université Grenoble Alpes, CNRS, IPAG,
38000
Grenoble,
France
27
Université de Paris Cité, Institut de physique du globe de Paris, CNRS,
1 rue Jussieu,
75005
Paris,
France
28
Institute of Planetary Research, German Aerospace Center (DLR),
Rutherfordstrasse 2,
12489
Berlin,
Germany
29
INAF, Osservatorio Astrofisico di Torino,
Via Osservatorio, 20,
10025
Pino Torinese To,
Italy
30
Centre for Mathematical Sciences, Lund University,
Box 118,
221 00
Lund,
Sweden
31
Centre Vie dans l’Univers, Faculté des sciences, Université de Genève,
Quai Ernest-Ansermet 30,
1211
Genève 4,
Switzerland
32
Thüringer Landessternwarte Tautenburg,
Sternwarte 5,
07778
Tautenburg,
Germany
33
Leiden Observatory, University of Leiden,
PO Box 9513,
2300 RA
Leiden,
The Netherlands
34
Department of Space, Earth and Environment, Chalmers University of Technology,
Onsala Space Observatory,
439 92
Onsala,
Sweden
35
Department of Astrophysics, University of Vienna,
Türkenschanzs-trasse 17,
1180
Vienna,
Austria
36
Konkoly Observatory, Research Centre for Astronomy and Earth Sciences,
1121
Budapest,
Konkoly Thege Miklós út 15–17,
Hungary
37
ELTE Eötvös Loránd University, Institute of Physics,
Pázmány Péter sétány 1/A,
1117
Budapest,
Hungary
38
IMCCE, UMR8028 CNRS, Observatoire de Paris, PSL Univ., Sorbonne Univ.,
77 av. Denfert-Rochereau,
75014
Paris,
France
39
Institut d’astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie,
98bis blvd. Arago,
75014
Paris,
France
40
Astrophysics Group, Lennard Jones Building, Keele University,
Staffordshire
ST5 5BG,
UK
41
European Southern Observatory,
Karl-Schwarzschild-Straße 2,
Garching bei München
85748,
Germany
42
Mullard Space Science Laboratory, University College London,
Holmbury St. Mary, Dorking,
Surrey
RH5 6NT,
UK
43
INAF, Osservatorio Astrofisico di Catania,
Via S. Sofia 78,
95123
Catania,
Italy
44
Institute of Optical Sensor Systems, German Aerospace Center (DLR),
Rutherfordstrasse 2,
12489
Berlin,
Germany
45
Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università degli Studi di Padova,
Vicolo dell’Osservatorio 3,
35122
Padova,
Italy
46
Department of Physics, University of Warwick,
Gibbet Hill Road,
Coventry
CV4 7AL,
UK
47
ETH Zurich, Department of Physics,
Wolfgang-Pauli-Strasse 2,
8093
Zurich,
Switzerland
48
Zentrum für Astronomie und Astrophysik, Technische Universität Berlin,
Hardenbergstr. 36,
10623
Berlin,
Germany
49
Institut für Geologische Wissenschaften, Freie Universität Berlin,
Maltheserstrasse 74–100,
12249
Berlin,
Germany
50
ELTE Eötvös Loránd University, Gothard Astrophysical Observatory,
9700
Szombathely,
Szent Imre h. u. 112,
Hungary
51
HUN-REN-ELTE Exoplanet Research Group,
9700
Szombathely,
Szent Imre h. u. 112,
Hungary
52
Institute of Astronomy, University of Cambridge,
Madingley Road,
Cambridge
CB3 0HA,
UK
Received:
18
August
2023
Accepted:
22
March
2024
Context. The HD 15337 (TIC 120896927, TOI-402) system was observed by the Transiting Exoplanet Survey Satellite (TESS), revealing the presence of two short-period planets situated on opposite sides of the radius gap. This offers an excellent opportunity to study theories of formation and evolution, as well as to investigate internal composition and atmospheric evaporation.
Aims. We aim to constrain the internal structure and composition of two short-period planets situated on opposite sides of the radius valley: HD 15337 b and c. We use new transit photometry and radial velocity data.
Methods. We acquired 6 new transit visits with the CHaracterising ExOPlanet Satellite (CHEOPS) and 32 new radial velocity measurements from the High Accuracy Radial Velocity Planet Searcher (HARPS) to improve the accuracy of the mass and radius estimates for both planets. We re-analysed the light curves from TESS sectors 3 and 4 and analysed new data from sector 30, correcting for long-term stellar activity. Subsequently, we performed a joint fit of the TESS and CHEOPS light curves, along with all available RV data from HARPS and the Planet Finder Spectrograph (PFS). Our model fit the planetary signals, stellar activity signal, and instrumental decorrelation model for the CHEOPS data simultaneously. The stellar activity was modelled using a Gaussian-process regression on both the RV and activity indicators. Finally, we employed a Bayesian retrieval code to determine the internal composition and structure of the planets.
Results. We derived updated and highly precise parameters for the HD 15337 system. Our improved precision on the planetary parameters makes HD 15337 b one of the most precisely characterised rocky exoplanets, with radius and mass measurements achieving a precision better than 2% and 7%, respectively. We were able to improve the precision of the radius measurement of HD 15337 c to 3%. Our results imply that the composition of HD 15337 b is predominantly rocky, while HD 15337 c exhibits a gas envelope with a mass of at least 0.01 M⊕.
Conclusions. Our results lay the groundwork for future studies, which can further unravel the atmospheric evolution of these exoplanets and offer new insights into their composition and formation history as well as the causes behind the radius gap.
Key words: techniques: photometric / techniques: radial velocities / planets and satellites: composition / stars: individual: HD 15337 / stars: individual: TOI-402 / stars: individual: TIC 12089692
The data are available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/686/A282
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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