Mass determination of the three long-period Neptune- and sub-Neptune-sized planets transiting TOI-282
Year: 2025
Type: article
Abstract: TOI-282 is a bright (V = 9.38) F8 main-sequence star known to host three transiting long-period ( P b = 22.9 d, P c = 56.0 d, and P d = 84.3 d) small ( R p ≈ 2–4 R ⊕ ) planets. The orbital period ratio of the two outermost planets, namely TOI-282 c and d, is close to the 3:2 commensurability, suggesting that the planets might be trapped in a mean motion resonance. We combined space-borne photometry from the TESS telescope with high-precision HARPS and ESPRESSO Doppler measurements to refine orbital parameters, measure the planetary masses, and investigate the architecture and evolution of the system. We performed a Markov chain Monte Carlo joint analysis of the transit light curves and radial velocity time series, and carried out a dynamical analysis to model transit timing variations and Doppler measurements along with N -body integration. In agreement with previous results, we found that TOI-282 b, c, and d have radii of R b = 2.69 ± 0.23 R ⊕ , R c = 4.13 −0.14 +0.16 R ⊕ , and R d = 3.11 ± 0.15 R ⊕ , respectively. We measured planetary masses of M b = 6.2 ± 1.6 M ⊕ , M c = 9.2 ± 2.0 M ⊕ , and M d = 5.8 −1.1 +0.9 M ⊕ , which imply mean densities of ρ b = 1.8 −0.6 +0.7 g cm −3 , ρ c = 0.7 ± 0.2 g cm −3 , and ρ d = 1.1 −0.2 +0.3 g cm −3 , respectively. The three planets may be water worlds, making TOI-282 an interesting system for future atmospheric follow-up observations with JWST and ELT.
Source: Astronomy and Astrophysics
Institutions: Austrian Academy of Sciences, Space Research Institute, University of Turin, European Southern Observatory, European Southern Observatory, University of Padua, University of Trento, Leiden Observatory, Chalmers University of Technology, Osservatorio Astrofisico di Torino, National Institute for Astrophysics, McDonald Observatory, The University of Texas at Austin, Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR), National Institutes of Natural Sciences, The Graduate University for Advanced Studies, SOKENDAI, Astrobiology Center, National Astronomical Observatory of Japan, Nicolaus Copernicus University, Universidad de La Laguna, Instituto de Astrofísica de Canarias, Wesleyan University, University of Cologne, Rhenish Institute for Environmental Research
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W4415675135
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