The inflated, eccentric warm Jupiter TOI-4914 b orbiting a metal-poor star, and the hot Jupiters TOI-2714 b and TOI-2981 b
Year: 2024
Type: article
Abstract: Recent observations of giant planets have revealed unexpected bulk densities. Hot Jupiters, in particular, appear larger than expected for their masses compared to planetary evolution models, while warm Jupiters seem denser than expected. These differences are often attributed to the influence of the stellar incident flux, but it has been unclear if they also result from different planet formation processes, and if there is a trend linking the planetary density to the chemical composition of the host star. In this work, we present the confirmation of three giant planets in orbit around solar analogue stars. TOI-2714 b ( P ≃ 2.5 d, R p ≃ 1.22 R J , M p = 0.72 M J ) and TOI-2981 b ( P ≃ 3.6 d, R P ≃ 1.2 R J , M P = 2 M J ) are hot Jupiters on nearly circular orbits, while TOI-4914 b ( P ≃ 10.6 d, R P ≃ 1.15 R J , M p = 0.72 M J ) is a warm Jupiter with a significant eccentricity ( e = 0.41 ± 0.02) that orbits a star more metal-poor ([Fe/H] = −0.13) than most of the stars known to host giant planets. Similarly, TOI-2981 b orbits a metal-poor star ([Fe/H] = −0.11), while TOI-2714 b orbits a metal-rich star ([Fe/H] = 0.30). Our radial velocity follow-up with the HARPS spectrograph allows us to detect their Keplerian signals at high significance (7, 30, and 23 σ , respectively) and to place a strong constraint on the eccentricity of TOI-4914 b (18 σ ). TOI-4914 b, with its large radius ( R p ≃ 1.15 R J ) and low insolation flux ( F ⋆ < 2 × 108 erg s −1 cm −2 ), appears to be more inflated than what is supported by current theoretical models for giant planets. Moreover, it does not conform to the previously noted trend that warm giant planets orbiting metal-poor stars have low eccentricities. This study thus provides insights into the diverse orbital characteristics and formation processes of giant exoplanets, in particular the role of stellar metallicity in the evolution of planetary systems.
DOI: 10.17615/t13p-0811
Authors: Bieryla, A., Seager, S., Marzari, F., Collins, K. A., Rowden, P., Piotto, G., Mignon, L., Desidera, S., Malavolta, L., Granata, V., Wilson, T. G., Relles, H. M., Mantovan, G., Montalto, M., Cameron, A. Collier, Watkins, C. N., Mann, A. W., Jenkins, J. M., Radford, D. J., Latham, D. W., Majidi, F. Z., Nascimbeni, V., Kostov, V., Winn, J. N., Zingales, T., Fausnaugh, M. M., Timmermans, M., Nardiello, D., Evans, P., Pozuelos, F. J., Borsato, L., Biazzo, K., Tan, T. -G., Barkaoui, K., Stassun, K. G.
Institution: University of North Carolina at Chapel Hill
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Aeronautics and Space Administration, Michigan State University, UK Space Agency, Space Telescope Science Institute, University of Warwick, Fonds De La Recherche Scientifique - FNRS, Fédération Wallonie-Bruxelles, Ministério da Ciência, Tecnologia e Inovação, Agenzia Spaziale Italiana, Ministerio de Ciencia e Innovación, Ministerio de Asuntos Económicos y Transformación Digital, Gobierno de España, National Academy of Sciences, Ames Research Center, College of Engineering, Michigan State University, University of North Carolina at Chapel Hill, Science Mission Directorate, Arts and Humanities Research Council, Science and Technology Facilities Council, Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture, Agencia Estatal de Investigación
OpenAlex ID: W4404402353