TOI−757 b: an eccentric transiting mini−Neptune on a 17.5−d orbit

Autor(en): A. Alqasim, N. Grieves, N. M. Rosário, D. Gandolfi, J. H. Livingston, S. Sousa, K. A. Collins, J. K. Teske, M. Fridlund, J. A. Egger, J. Cabrera, C. Hellier, A. F. Lanza, V. Van Eylen, F. Bouchy, R. J. Oelkers, G. Srdoc, S. Shectman, M. Günther, E. Goffo, T. Wilson, L. M. Serrano, A. Brandeker, S. X. Wang, A. Heitzmann, A. Bonfanti, L. Fossati, Y. Alibert, L. Delrez, R. Sefako, S. Barros, K. I. Collins, O. D.S. Demangeon, S. H. Albrecht, R. Alonso, J. Asquier, T. Barczy, D. Barrado, W. Baumjohann, T. Beck, W. Benz, N. Billot, L. Borsato, C. Broeg, E. M. Bryant, R. P. Butler, W. D. Cochran, A. Collier Cameron, A. C.M. Correia, J. D. Crane, Sz Csizmadia, P. E. Cubillos, M. B. Davies, T. Daylan, M. Deleuil, A. Deline, B. O. Demory, A. Derekas, B. Edwards, D. Ehrenreich, A. Erikson, Z. Essack, A. Fortier, K. Gazeas, M. Gillon, M. Güdel, J. Hasiba, A. P. Hatzes, Ch Helling, T. Hirano, S. B. Howell, S. Hoyer, K. G. Isaak, J. M. Jenkins, S. Kanodia, L. L. Kiss, J. Korth, K. W.F. Lam, J. Laskar, A. Lecavelier des Etangs, M. Lendl, M. B. Lund, R. Luque, A. W. Mann, D. Magrin, P. F.L. Maxted, C. Mordasini, N. Narita, V. Nascimbeni, G. Nowak, G. Olofsson, H. P. Osborn, H. L.M. Osborne, D. Osip, R. Ottensamer, I. Pagano, E. Palle, G. Peter, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, S. Redfield, I. Ribas, M. Rice, G. R. Ricker, M. Rieder, S. Salmon, N. C. Santos, G. Scandariato, S. Seager, D. Segransan, A. Shporer, A. E. Simon, A. M.S. Smith, M. Stalport, Gy M. Szabo, I. Thompson, J. D. Twicken, S. Udry, R. Vanderspek, V. Van Grootel, J. Venturini, E. Villaver, J. Villaseñor, V. Viotto, I. Walter, N. A. Walton, J. N. Winn, S. W. Yee
Abstrakt: We report the spectroscopic confirmation and fundamental properties of TOI−757 b, a mini−Neptune on a 17.5−d orbit transiting a bright star (V = 9.7 mag) discovered by the TESS mission. We acquired high−precision radial velocity measurements with the HARPS, ESPRESSO, and PFS spectrographs to confirm the planet detection and determine its mass. We also acquired space−borne transit photometry with the CHEOPS space telescope to place stronger constraints on the planet radius, supported with ground−based LCOGT photometry. WASP and KELT photometry were used to help constrain the stellar rotation period. We also determined the fundamental parameters of the host star. We find that TOI−757 b has a radius of R_p = 2.5 ± 0.1R_. and a mass of M_p = 10.5⁺₋₂²₁²M, implying a bulk density of ρ_p = 3.6 ± 0.8 g cm⁻³. Our internal composition modelling was unable to constrain the composition of TOI−757 b, highlighting the importance of atmospheric observations for the system. We also find the planet to be highly eccentric with e = 0.39⁺₋₀⁰₀₇⁰⁸, making it one of the very few highly eccentric planets among precisely characterized mini−Neptunes. Based on comparisons to other similar eccentric systems, we find a likely scenario for TOI−757 b’s formation to be high eccentricity migration due to a distant outer companion. We additionally propose the possibility of a more intrinsic explanation for the high eccentricity due to star−star interactions during the earlier epoch of the Galactic disc formation, given the low metallicity and older age of TOI−757.
Organisation(en): Institut für Astrophysik
Externe Organisation(en): University College London, Universität Genf, Universidade do Porto, Università degli Studi di Torino, University of Tokyo, Harvard-Smithsonian Center for Astrophysics, Carnegie Institution for Science, Chalmers University of Technology, Leiden University, Universität Bern, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Keele University, INAF-Osservatorio Astrofisico di Catania, Texas A&M University, University of Texas, Brownsville, Kotizarovci Observatory, European Space Research & Technology Centre (ESA/ESTEC), Thüringer Landessternwarte Tautenburg, Technische Universität Graz, University of Warwick, Stockholm University, Tsinghua University, Österreichische Akademie der Wissenschaften (ÖAW), Université de Liège, Katholieke Universiteit Leuven, South African Astronomical Observatory, Princeton University, George Mason University, Aarhus University, Instituto de Astrofísica de Canarias (IAC), Universidad de La Laguna, Admatis, European Space Astronomy Centre (ESA), INAF - Osservatorio Astronomico di Padova, University of Texas, Austin, University of St. Andrews, Universidade de Coimbra, INAF-Osservatorio Astrofisico di Torino, Lund University, McDonnell Center for the Space Sciences, Aix-Marseille Université, Eötvös Loránd University Budapest, SRON Netherlands Institute for Space Research , University of New Mexico, Universität Wien, National Institutes of Natural Sciences (NINS) , National Astronomical Observatory of Japan, National Aeronautics & Space Administration (NASA), MTA Társadalomtudományi Kutatóközpont, Lund Observatory, Université de recherche Paris Sciences et Lettres, Université Paris VI - Pierre-et-Marie-Curie, California Institute of Technology (Caltech), University of Chicago, The University of North Carolina at Chapel Hill, Nicolaus Copernicus University, Massachusetts Institute of Technology, European Southern Observatory (Germany), Las Campanas Observatory, National & Kapodistrian University of Athens, Università degli Studi di Padova, Eidgenössische Technische Hochschule Zürich, University of Cambridge, Technische Universität Berlin, Freie Universität Berlin (FU), Wesleyan University, Spanish National Research Council (CSIC), Institut d'Estudis Espacials de Catalunya (IEEC), Yale University, HUN-REN-ELTE Exoplanet Research Group, SETI Institute
Journal: Monthly Notices of the Royal Astronomical Society
Band: 533
Seiten: 1-26
Anzahl der Seiten: 26
ISSN: 0035-8711
DOI: https://doi.org/10.1093/mnras/stae1767
Publikationsdatum: 09-2024
Peer-reviewed: Ja
ÖFOS 2012: 103003 Astronomie, 103004 Astrophysik, 103038 Weltraumforschung
Schlagwörter
ASJC Scopus Sachgebiete: Astronomy and Astrophysics, Space and Planetary Science
Link zum Portal: https://ucrisportal.univie.ac.at/de/publications/1a1cb328-ac59-43cf-a79a-c78361eed346

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