TOI-544 b: a potential water-world inside the radius valley in a two-planet system-Reference-Cited by-同舟云学术

TOI-544 b: a potential water-world inside the radius valley in a two-planet system

Published:2023-12-13 Issue:4 Volume:527 Page:11138-11157
ISSN:0035-8711
Container-title:Monthly Notices of the Royal Astronomical Society
language:en
Short-container-title:

Author:

Osborne H L M¹²^ORCID,Van Eylen V¹^ORCID,Goffo E³⁴,Gandolfi D³^ORCID,Nowak G⁵⁶⁷^ORCID,Persson C M⁸,Livingston J⁹¹⁰¹¹^ORCID,Weeks A¹,Pallé E⁶⁷,Luque R¹²^ORCID,Hellier C¹³,Carleo I⁶,Redfield S¹⁴,Hirano T⁹¹⁰¹¹,Garbaccio Gili M³,Alarcon J¹⁵,Barragán O¹⁶,Casasayas-Barris N⁶⁷,Díaz M R¹⁷,Esposito M⁴,Knudstrup E¹⁸,Jenkins J S¹⁹²⁰,Murgas F⁶⁷,Orell-Miquel J⁶⁷,Rodler F¹⁵,Serrano L³,Stangret M⁶⁷,Albrecht S H¹⁸,Alqasim A¹,Cochran W D²¹,Deeg H J¹²²²,Fridlund M⁸²³,Hatzes A P⁴,Korth J²⁴,Lam K W F²⁵

Affiliation:

1. Mullard Space Science Laboratory, University College London , Holmbury St Mary, Dorking, Surrey RH5 6NT , UK

2. European Southern Observatory , Karl-Schwarzschild-Straße 2, D-85748 Garching bei München , Germany

3. Dipartimento di Fisica, Universitá di Torino , via P. Giuria 1, I-10125 Torino , Italy

4. Thüringer Landessternwarte Tautenburg , Sternwarte 5, D-07778 Tautenburg , Germany

5. Institute of Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University , Grudzia̧dzka 5, PL-87-100 Toruń , Poland

6. Instituto de Astrofísica de Canarias (IAC) , c/ Via Lactea, s/n, E-38205 La Laguna, Tenerife , Spain

7. Departamento de Astrofísica, Universidad de La Laguna (ULL) , E-38206 La Laguna, Tenerife , Spain

8. Department of Space, Earth and Environment, Chalmers University of Technology , Onsala Space Observatory, SE-439 92 Onsala , Sweden

9. Astrobiology Center , 2-21-1 Osawa, Mitaka, Tokyo 181-8588 , Japan

10. National Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588 , Japan

11. Department of Astronomy, The Graduate University for Advanced Studies (SOKENDAI) , 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 Japan

12. Department of Astronomy and Astrophysics, University of Chicago , Chicago, IL 60637 , USA

13. Astrophysics Group, Keele University , Staffordshire ST5 5BG , UK

14. Astronomy Department and Van Vleck Observatory, Wesleyan University , Middletown, CT 06459 , USA

15. European Southern Observatory , Alonso de Cordova 3107, 7630391 Vitacura, Santiago de Chile , Chile

16. Sub-department of Astrophysics, Department of Physics, University of Oxford , Oxford OX1 3RH , UK

17. Las Campanas Observatory, Carnegie Institution of Washington , Colina el Pino, Casilla 601, La Serena , Chile

18. Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University , Ny Munkegade 120, DK-8000 Aarhus C , Denmark

19. Instituto de Astrofísica de Andalucía (IAA-CSIC) , Glorieta de la Astronomía s/n, E-18008 Granada , Spain

20. Centro de Astrofísica y Tecnologías Afines (CATA) , Casilla 36-D, Santiago, 7591245 Chile

21. McDonald Observatory and Center for Planetary Systems Habitability, The University of Texas TX 78712-1206 , Austin, Texas , USA

22. Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales , Av. Ejército 441, Santiago , Chile

23. Leiden Observatory, University of Leiden , PO Box 9513, NL-2300 RA Leiden, The Netherlands

24. Lund Observatory, Division of Astrophysics, Department of Physics, Lund University , Box 43, SE-22100 Lund , Sweden

25. Institute of Planetary Research, German Aerospace Center (DLR) , Rutherfordstrasse 2, D-12489 Berlin , Germany

Abstract

ABSTRACT We report on the precise radial velocity follow-up of TOI-544 (HD 290498), a bright K star (V = 10.8), which hosts a small transiting planet recently discovered by the Transiting Exoplanet Survey Satellite (TESS). We collected 122 high-resolution High Accuracy Radial velocity Planet Searcher (HARPS) and HARPS-N spectra to spectroscopically confirm the transiting planet and measure its mass. The nearly 3-yr baseline of our follow-up allowed us to unveil the presence of an additional, non-transiting, longer-period companion planet. We derived a radius and mass for the inner planet, TOI-544 b, of 2.018 ± 0.076 R⊕ and 2.89 ± 0.48 M⊕, respectively, which gives a bulk density of $1.93^{+0.30}_{-0.25}$ g cm−3. TOI-544 c has a minimum mass of 21.5 ± 2.0 M⊕ and orbital period of 50.1 ± 0.2 d. The low density of planet-b implies that it has either an Earth-like rocky core with a hydrogen atmosphere, or a composition which harbours a significant fraction of water. The composition interpretation is degenerate depending on the specific choice of planet interior models used. Additionally, TOI-544 b has an orbital period of 1.55 d and equilibrium temperature of 999 ± 14 K, placing it within the predicted location of the radius valley, where few planets are expected. TOI-544 b is a top target for future atmospheric observations, for example with JWST, which would enable better constraints of the planet composition.

Funder

Science and Technology Facilities Council

Swedish National Space Agency

Ministry of Education and Science

University of La Laguna

DFG

Ministry of Science and Innovation

AEI

Deutsche Forschungsgemeinschaft

FONDECYT

Swedish Research Council

Publisher