Tidal evolution of exoplanetary systems hosting potentially habitable exoplanets. The cases of LHS-1140 b-c and K2-18 b-c

Autor(es)

Gomes, G. O. ^{[1, 2]} ; Ferraz-Mello, S. ^[1]

Afiliação do(s) autor(es)

^[1] IAG USP, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao 1226, BR-05508900 Sao Paulo - Brazil

^[2] Univ Geneva, Observ Geneve, 51 Chemin Maillettes, CH-1290 Sauverny - Switzerland

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 494, n. 4, p. 5082-5090, JUN 2020.
• Citações Web of Science: 0

Resumo

We present a model to study secularly and tidally evolving three-body systems composed by two low-mass planets orbiting a star, in the case where the bodies rotation axes are always perpendicular to the orbital plane. The tidal theory allows us to study the spin and orbit evolution of both stiff Earth-like planets and predominantly gaseous Neptune-like planets. The model is applied to study two recently discovered exoplanetary systems containing potentially habitable exoplanets (PHE): LHS-1140 b-c and K2-18 b-c. For the former system, we show that both LHS-1140 b and c must be in nearly circular orbits. For K2-18 b-c, the combined analysis of orbital evolution time-scales with the current eccentricity estimation of K2-18 b allows us to conclude that the inner planet (K2-18 c) must be a Neptune-like gaseous body. Only this would allow for the eccentricity of K2-18 b to be in the range of values estimated in recent works (e = 0.20 +/- 0.08), provided that the uniform viscosity coefficient of K2-18 b is greater than 2.4 x 10(19) Pa s (which is a value characteristic of stiff bodies) and supposing that such system has an age of some Gyr. (AU)

• Processo FAPESP: 17/25224-0 - Aplicação da teoria das marés planetárias a exoplanetas e satélites planetários
• Beneficiário: Gabriel de Oliveira Gomes
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 16/13750-6 - O Brasil no espaço: Astrofísica e Engenharia
• Beneficiário: Eduardo Janot Pacheco
• Modalidade de apoio: Auxílio à Pesquisa - Projetos Especiais
• Processo FAPESP: 19/21201-0 - Evolução tidal de exoplanetas e estrelas hospedeiras
• Beneficiário: Gabriel de Oliveira Gomes
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto