TOI-2015 b: A sub-Neptune in strong gravitational interaction with an outer non-transiting planet

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. Yalçinkaya; 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; 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; S. Zúñiga-Fernández

doi:10.1051/0004-6361/202452916

TOI-2015 b: A sub-Neptune in strong gravitational interaction with an outer non-transiting planet

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. Yalçinkaya, 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, 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, S. Zúñiga-Fernández

Instituto de Alta Investigación

University of Liege
Massachusetts Institute of Technology
Instituto de Astrofísica de Canarias
Lund University
University of Hawai'i at Mānoa
University of Vienna
University of Washington
University of La Laguna
Glorieta de la Astronomía S/n
The University of Tokyo
National Institutes of Natural Sciences - AstroBiology Center
Swiss Federal Institute of Technology Zurich
University of Zurich
The University of Chicago
National Institute for Astrophysics
University of California at San Diego
Gemini Observatory
Technical University of Madrid
National Institutes of Natural Sciences - National Astronomical Observatory of Japan
University of Hamburg
Harvard-Smithsonian Center for Astrophysics
California Institute of Technology
Ankara University
Université Paris-Saclay
University of Birmingham
Cadi Ayyad University
Stanford University
American Association of Variable Star Observers
George Mason University
University of California at Berkeley
University of Granada
University of Bern
Simons Foundation
Universidad Nacional Autónoma de México
ESTEC
University of St Andrews
University of Cambridge
Northwestern University
Kyoto University
NASA Ames Research Center
Ritsumeikan University
University of Louisville
Free University of Berlin
Sabadell Astronomical Society
Royal Belgian Institute for Space Aeronomy
The Graduate University for Advanced Studies
University of Rome Tor Vergata
Max Planck Institute for Astronomy
Villa '39 Observatory
Universities Space Research Association
Wild Boar Remote Observatory
Aristotle University of Thessaloniki
University of Maryland, College Park
RASC (Royal Astronomical Society of Canada)
South African Astronomical Observatory
Keele University
Astronomical Observatory of Padua
University of Amsterdam
Heidelberg University
Kotizarovci Observatory
Academia Sinica - Institute of Astronomy and Astrophysics
National Taiwan University
Johns Hopkins University
Union College
Princeton University
Stephen F. Austin State University

Producción científica: Contribución a una revista › Artículo › revisión exhaustiva

5 Citas (Scopus)

Resumen

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 K = 10.3 mag M4-type dwarf with a subsolar metallicity of [Fe/H] =-0.31 ± 0.16, and an effective temperature of T_eff ≈ 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 P_b = 3.34 days, a mass of M_p = 9.02_-0.36^+0.32M_⊕, and a radius of R_p = 3.309_-0.011^+0.013R_⊕, resulting in a density of ρ_p = 0.25 ± 0.01 ρ_⊕ = 1.40 ± 0.06 g cm^-3; 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 P_c = 5.583 days and a mass of M_p = 8.91_-0.40^+0.38M_⊕. 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 JWST 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.

Idioma original	Inglés
Número de artículo	A281
Publicación	Astronomy and Astrophysics
Volumen	695
DOI	https://doi.org/10.1051/0004-6361/202452916
Estado	Publicada - 1 mar 2025

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Barkaoui, K., Korth, J., Gaidos, E., Agol, E., Parviainen, H., Pozuelos, F. J., Palle, E., Narita, N., Grimm, S., Brady, M., Bean, J. L., Morello, G., Rackham, B. V., Burgasser, A. J., Van Grootel, V., Rojas-Ayala, B., Seifahrt, A., Marfil, E., Passegger, V. M., ... Zúñiga-Fernández, S. (2025). TOI-2015 b: A sub-Neptune in strong gravitational interaction with an outer non-transiting planet. Astronomy and Astrophysics, 695, Artículo A281. https://doi.org/10.1051/0004-6361/202452916

@article{3e6b924848b743eda2b113bf20726b3a,

title = "TOI-2015 b: A sub-Neptune in strong gravitational interaction with an outer non-transiting planet",

abstract = "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 K = 10.3 mag M4-type dwarf with a subsolar metallicity of [Fe/H] =-0.31 ± 0.16, and an effective temperature of Teff ≈ 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 Pb = 3.34 days, a mass of Mp = 9.02-0.36+0.32M⊕, and a radius of Rp = 3.309-0.011+0.013R⊕, resulting in a density of ρp = 0.25 ± 0.01 ρ⊕ = 1.40 ± 0.06 g cm-3; 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 Pc = 5.583 days and a mass of Mp = 8.91-0.40+0.38M⊕. 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 JWST 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.",

keywords = "Planets and satellites: detection, Planets and satellites: formation, Stars: individual: TOI-2015",

author = "K. Barkaoui and J. Korth and E. Gaidos and E. Agol and H. Parviainen and Pozuelos, \{F. J.\} and E. Palle and N. Narita and S. Grimm and M. Brady and Bean, \{J. L.\} and G. Morello and Rackham, \{B. V.\} and Burgasser, \{A. J.\} and \{Van Grootel\}, V. and B. Rojas-Ayala and A. Seifahrt and E. Marfil and Passegger, \{V. M.\} and M. Stalport and M. Gillon and Collins, \{K. A.\} and A. Shporer and S. Giacalone and S. Yal{\c c}inkaya and E. Ducrot and M. Timmermans and Triaud, \{A. H.M.J.\} and \{De Wit\}, J. and A. Soubkiou and Watkins, \{C. N.\} and C. Aganze and R. Alonso and Amado, \{P. J.\} and R. Basant and Ba{\c s}t{\"u}rk and Z. Benkhaldoun and A. Burdanov and Y. Calatayud-Borras and J. Chouqar and Conti, \{D. M.\} and Collins, \{K. I.\} and F. Davoudi and L. Delrez and Dressing, \{C. D.\} and \{De Leon\}, J. and M. D{\'e}vora-Pajares and Demory, \{B. O.\} and G. Dransfield and E. Esparza-Borges and G. Fern{\'a}ndez-Rodriguez and I. Fukuda and A. Fukui and Gallardo, \{P. P.M.\} and L. Garcia and Garcia, \{N. A.\} and M. Ghachoui and S. Gerald{\'i}a-Gonz{\'a}lez and \{G{\'o}mez Maqueo Chew\}, Y. and J. Gonz{\'a}lez-Rodr{\'i}guez and G{\"u}nther, \{M. N.\} and Y. Hayashi and K. Horne and Hooton, \{M. J.\} and Hsu, \{C. C.\} and K. Ikuta and K. Isogai and E. Jehin and Jenkins, \{J. M.\} and K. Kawauchi and T. Kagetani and Y. Kawai and D. Kasper and Kielkopf, \{J. F.\} and P. Klagyivik and G. Lacedelli and Latham, \{D. W.\} and F. Libotte and R. Luque and Livingston, \{J. H.\} and L. Mancini and B. Massey and M. Mori and \{Mu{\~n}oz Torres\}, S. and F. Murgas and P. Niraula and J. Orell-Miquel and David Rapetti and R. Rebolo-L{\'o}pez and G. Ricker and R. Papini and Pedersen, \{P. P.\} and A. Pel{\'a}ez-Torres and P{\'e}rez-Prieto, \{J. A.\} and E. Poultourtzidis and Rodriguez, \{P. M.\} and D. Queloz and Savel, \{A. B.\} and N. Schanche and M. S{\'a}nchez-Benavente and L. Sibbald and R. Sefako and S. Sohy and A. Sota and Schwarz, \{R. P.\} and S. Seager and D. Sebastian and J. Southworth and M. Stangret and G. Stef{\'a}nsson and J. St{\"u}rmer and G. Srdoc and Thompson, \{S. J.\} and Y. Terada and R. Vanderspek and G. Wang and N. Watanabe and Wilkin, \{F. P.\} and J. Winn and Wells, \{R. D.\} and C. Ziegler and S. Z{\'u}{\~n}iga-Fern{\'a}ndez",

note = "Publisher Copyright: {\textcopyright} The Authors 2025.",

year = "2025",

month = mar,

day = "1",

doi = "10.1051/0004-6361/202452916",

language = "English",

volume = "695",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

}

Barkaoui, K, Korth, J, Gaidos, E, Agol, E, Parviainen, H, Pozuelos, FJ, Palle, E, Narita, N, Grimm, S, Brady, M, Bean, JL, Morello, G, Rackham, BV, Burgasser, AJ, Van Grootel, V, Rojas-Ayala, B, Seifahrt, A, Marfil, E, Passegger, VM, Stalport, M, Gillon, M, Collins, KA, Shporer, A, Giacalone, S, Yalçinkaya, S, Ducrot, E, Timmermans, M, Triaud, AHMJ, De Wit, J, Soubkiou, A, Watkins, CN, Aganze, C, Alonso, R, Amado, PJ, Basant, R, Baştürk, Benkhaldoun, Z, Burdanov, A, Calatayud-Borras, Y, Chouqar, J, Conti, DM, Collins, KI, Davoudi, F, Delrez, L, Dressing, CD, De Leon, J, Dévora-Pajares, M, Demory, BO, Dransfield, G, Esparza-Borges, E, Fernández-Rodriguez, G, Fukuda, I, Fukui, A, Gallardo, PPM, Garcia, L, Garcia, NA, Ghachoui, M, Geraldía-González, S, Gómez Maqueo Chew, Y, González-Rodríguez, J, Günther, MN, Hayashi, Y, Horne, K, Hooton, MJ, Hsu, CC, Ikuta, K, Isogai, K, Jehin, E, Jenkins, JM, Kawauchi, K, Kagetani, T, Kawai, Y, Kasper, D, Kielkopf, JF, Klagyivik, P, Lacedelli, G, Latham, DW, Libotte, F, Luque, R, Livingston, JH, Mancini, L, Massey, B, Mori, M, Muñoz Torres, S, Murgas, F, Niraula, P, Orell-Miquel, J, Rapetti, D, Rebolo-López, R, Ricker, G, Papini, R, Pedersen, PP, Peláez-Torres, A, Pérez-Prieto, JA, Poultourtzidis, E, Rodriguez, PM, Queloz, D, Savel, AB, Schanche, N, Sánchez-Benavente, M, Sibbald, L, Sefako, R, Sohy, S, Sota, A, Schwarz, RP, Seager, S, Sebastian, D, Southworth, J, Stangret, M, Stefánsson, G, Stürmer, J, Srdoc, G, Thompson, SJ, Terada, Y, Vanderspek, R, Wang, G, Watanabe, N, Wilkin, FP, Winn, J, Wells, RD, Ziegler, C & Zúñiga-Fernández, S 2025, 'TOI-2015 b: A sub-Neptune in strong gravitational interaction with an outer non-transiting planet', Astronomy and Astrophysics, vol. 695, A281. https://doi.org/10.1051/0004-6361/202452916

TY - JOUR

T1 - TOI-2015 b

T2 - A sub-Neptune in strong gravitational interaction with an outer non-transiting planet

AU - Barkaoui, K.

AU - Korth, J.

AU - Gaidos, E.

AU - Agol, E.

AU - Parviainen, H.

AU - Pozuelos, F. J.

AU - Palle, E.

AU - Narita, N.

AU - Grimm, S.

AU - Brady, M.

AU - Bean, J. L.

AU - Morello, G.

AU - Rackham, B. V.

AU - Burgasser, A. J.

AU - Van Grootel, V.

AU - Rojas-Ayala, B.

AU - Seifahrt, A.

AU - Marfil, E.

AU - Passegger, V. M.

AU - Stalport, M.

AU - Gillon, M.

AU - Collins, K. A.

AU - Shporer, A.

AU - Giacalone, S.

AU - Yalçinkaya, S.

AU - Ducrot, E.

AU - Timmermans, M.

AU - Triaud, A. H.M.J.

AU - De Wit, J.

AU - Soubkiou, A.

AU - Watkins, C. N.

AU - Aganze, C.

AU - Alonso, R.

AU - Amado, P. J.

AU - Basant, R.

AU - Baştürk,

AU - Benkhaldoun, Z.

AU - Burdanov, A.

AU - Calatayud-Borras, Y.

AU - Chouqar, J.

AU - Conti, D. M.

AU - Collins, K. I.

AU - Davoudi, F.

AU - Delrez, L.

AU - Dressing, C. D.

AU - De Leon, J.

AU - Dévora-Pajares, M.

AU - Demory, B. O.

AU - Dransfield, G.

AU - Esparza-Borges, E.

AU - Fernández-Rodriguez, G.

AU - Fukuda, I.

AU - Fukui, A.

AU - Gallardo, P. P.M.

AU - Garcia, L.

AU - Garcia, N. A.

AU - Ghachoui, M.

AU - Geraldía-González, S.

AU - Gómez Maqueo Chew, Y.

AU - González-Rodríguez, J.

AU - Günther, M. N.

AU - Hayashi, Y.

AU - Horne, K.

AU - Hooton, M. J.

AU - Hsu, C. C.

AU - Ikuta, K.

AU - Isogai, K.

AU - Jehin, E.

AU - Jenkins, J. M.

AU - Kawauchi, K.

AU - Kagetani, T.

AU - Kawai, Y.

AU - Kasper, D.

AU - Kielkopf, J. F.

AU - Klagyivik, P.

AU - Lacedelli, G.

AU - Latham, D. W.

AU - Libotte, F.

AU - Luque, R.

AU - Livingston, J. H.

AU - Mancini, L.

AU - Massey, B.

AU - Mori, M.

AU - Muñoz Torres, S.

AU - Murgas, F.

AU - Niraula, P.

AU - Orell-Miquel, J.

AU - Rapetti, David

AU - Rebolo-López, R.

AU - Ricker, G.

AU - Papini, R.

AU - Pedersen, P. P.

AU - Peláez-Torres, A.

AU - Pérez-Prieto, J. A.

AU - Poultourtzidis, E.

AU - Rodriguez, P. M.

AU - Queloz, D.

AU - Savel, A. B.

AU - Schanche, N.

AU - Sánchez-Benavente, M.

AU - Sibbald, L.

AU - Sefako, R.

AU - Sohy, S.

AU - Sota, A.

AU - Schwarz, R. P.

AU - Seager, S.

AU - Sebastian, D.

AU - Southworth, J.

AU - Stangret, M.

AU - Stefánsson, G.

AU - Stürmer, J.

AU - Srdoc, G.

AU - Thompson, S. J.

AU - Terada, Y.

AU - Vanderspek, R.

AU - Wang, G.

AU - Watanabe, N.

AU - Wilkin, F. P.

AU - Winn, J.

AU - Wells, R. D.

AU - Ziegler, C.

AU - Zúñiga-Fernández, S.

PY - 2025/3/1

Y1 - 2025/3/1

N2 - 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 K = 10.3 mag M4-type dwarf with a subsolar metallicity of [Fe/H] =-0.31 ± 0.16, and an effective temperature of Teff ≈ 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 Pb = 3.34 days, a mass of Mp = 9.02-0.36+0.32M⊕, and a radius of Rp = 3.309-0.011+0.013R⊕, resulting in a density of ρp = 0.25 ± 0.01 ρ⊕ = 1.40 ± 0.06 g cm-3; 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 Pc = 5.583 days and a mass of Mp = 8.91-0.40+0.38M⊕. 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 JWST 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.

AB - 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 K = 10.3 mag M4-type dwarf with a subsolar metallicity of [Fe/H] =-0.31 ± 0.16, and an effective temperature of Teff ≈ 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 Pb = 3.34 days, a mass of Mp = 9.02-0.36+0.32M⊕, and a radius of Rp = 3.309-0.011+0.013R⊕, resulting in a density of ρp = 0.25 ± 0.01 ρ⊕ = 1.40 ± 0.06 g cm-3; 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 Pc = 5.583 days and a mass of Mp = 8.91-0.40+0.38M⊕. 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 JWST 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.

KW - Planets and satellites: detection

KW - Planets and satellites: formation

KW - Stars: individual: TOI-2015

UR - https://www.scopus.com/pages/publications/105002256818

U2 - 10.1051/0004-6361/202452916

DO - 10.1051/0004-6361/202452916

M3 - Article

AN - SCOPUS:105002256818

SN - 0004-6361

VL - 695

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - A281

ER -