TOI-2015 b: a sub-Neptune in strong gravitational interaction with an outer non-transiting planet
TOI-2015 is a known exoplanetary system around an M4 dwarf star, consisting of a transiting sub-Neptune planet in a 3.35-day orbital period, TOI-2015 b, accompanied by a non-transiting companion, TOI-2015 c. High-precision radial-velocity measurements were taken with the MAROON-X spectrograph, and h...
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| Auteurs principaux: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Article (Journal) |
| Langue: | anglais |
| Publié: |
March 2025
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| In: |
Astronomy and astrophysics
Year: 2025, Volume: 695, Pages: 1-25 |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/202452916 |
| Accès en ligne: | Verlag, kostenfrei, Volltext: https://doi.org/10.1051/0004-6361/202452916 Verlag, kostenfrei, Volltext: https://www.aanda.org/articles/aa/abs/2025/03/aa52916-24/aa52916-24.html |
| Notes sur l'auteur: | K. Barkaoui, J. Korth, E. Gaidos, E. Agol, H. Parviainen, F.J. Pozuelos, E. Palle, N. Narita, S. Grimm, M. Brady, J.L. Bean, G. Morello, B.V. Rackham, A.J. Burgasser, V. Van Grootel, B. Rojas-Ayala, A. Seifahrt, E. Marfil, V.M. Passegger, M. Stalport, M. Gillon, K.A. Collins, A. Shporer, S. Giacalone, S. Yalçınkaya, E. Ducrot, M. Timmermans, A.H.M.J. Triaud, J. de Wit, A. Soubkiou, C.N. Watkins, C. Aganze, R. Alonso, P.J. Amado, R. Basant, Ö. Baştürk, Z. Benkhaldoun, A. Burdanov, Y. Calatayud-Borras, J. Chouqar, D.M. Conti, K.I. Collins, F. Davoudi, L. Delrez, C.D. Dressing, J. de Leon, M. Dévora-Pajares, B.O. Demory, G. Dransfield, E. Esparza-Borges, G. Fernández-Rodriguez, I. Fukuda, A. Fukui, P.P.M. Gallardo, L. Garcia, N.A. Garcia, M. Ghachoui, S. Geraldía-González, Y. Gómez Maqueo Chew, J. González-Rodríguez, M.N. Günther, Y. Hayashi, K. Horne, M.J. Hooton, C.C. Hsu, K. Ikuta, K. Isogai, E. Jehin, J.M. Jenkins, K. Kawauchi, T. Kagetani, Y. Kawai, D. Kasper, J.F. Kielkopf, P. Klagyivik, G. Lacedelli, D.W. Latham, F. Libotte, R. Luque, J.H. Livingston, L. Mancini, B. Massey, M. Mori, S. Muñoz Torres, F. Murgas, P. Niraula, J. Orell-Miquel, David Rapetti, R. Rebolo-López, G. Ricker, R. Papini, P.P. Pedersen, A. Peláez-Torres, J.A. Pérez-Prieto, E. Poultourtzidis, P.M. Rodriguez, D. Queloz, A.B. Savel, N. Schanche, M. Sánchez-Benavente, L. Sibbald, R. Sefako, S. Sohy, A. Sota, R.P. Schwarz, S. Seager, D. Sebastian, J. Southworth, M. Stangret, G. Stefánsson, J. Stürmer, G. Srdoc, S.J. Thompson, Y. Terada, R. Vanderspek, G. Wang, N. Watanabe, F.P. Wilkin, J. Winn, R.D. Wells, C. Ziegler, and S. Zúñiga-Fernández |
| Résumé: | TOI-2015 is a known exoplanetary system around an M4 dwarf star, consisting of a transiting sub-Neptune planet in a 3.35-day orbital period, TOI-2015 b, accompanied by a non-transiting companion, TOI-2015 c. High-precision radial-velocity measurements were taken with the MAROON-X spectrograph, and high-precision photometric data were collected, primarily using the SPECULOOS, MUSCAT, TRAPPIST and LCOGT networks. We collected 63 transit light curves and 49 different transit epochs for TOI-2015 b. We recharacterized the target star by combining optical spectra obtained by the MAROON-X, Shane/KAST and IRTF/SpeX spectrographs, Bayesian model averaging (BMA) and spectral energy distribution (SED) analysis. The TOI-2015 host star is a <i>K<i/> = 10.3 mag M4-type dwarf with a subsolar metallicity of [Fe/H] = −0.31 ± 0.16, and an effective temperature of <i>T<i/><sub>eff<sub/> ≈ 3200 K. Our photodynamical analysis of the system strongly favors the 5:3 mean-motion resonance and in this scenario the planet b (TOI-2015 b) has an orbital period of <i>P<sub>b<sub/><i/> = 3.34 days, a mass of , and a radius of , resulting in a density of <i>ρ<sub>p<sub/><i/> = 0.25 ± 0.01 <i>ρ<i/><sub>⊕<sub/> = 1.40 ± 0.06 g cm<sup>−3<sup/>; this is indicative of a Neptune-like composition. Its transits exhibit large (> 1 hr) timing variations characteristic of an outer perturber in the system. We performed a global analysis of the high-resolution radial-velocity measurements, the photometric data, and the TTVs, and inferred that TOI-2015 hosts a second planet, TOI-2015 c, in a non-transiting configuration. Our analysis places it near a 5:3 resonance with an orbital period of <i>P<sub>c<sub/><i/> = 5.583 days and a mass of . The dynamical configuration of TOI-2015 b and TOI-2015 c can be used to constrain the system’s planetary formation and migration history. Based on the mass-radius composition models, TOI-2015 b is a water-rich or rocky planet with a hydrogen-helium envelope. Moreover, TOI-2015 b has a high transmission-spectroscopic metric (TSM=149), making it a favorable target for future transmission spectroscopic observations with the <i>JWST<i/> to constrain the atmospheric composition of the planet. Such observations would also help to break the degeneracies in theoretical models of the planet’s interior structure. |
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| Description: | Gesehen am 21.07.2026 |
| Description matérielle: | Online Resource |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/202452916 |