| Texto completo | |
| Autor(es): |
Sumida, Viktor Yuri Dona
;
Estrela, Raissa
;
Valio, Adriana
Número total de Autores: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ASTROPHYSICAL JOURNAL; v. 994, n. 2, p. 14-pg., 2025-12-01. |
| Resumo | |
M dwarfs have long been prime targets in the search for habitable exoplanets, owing to their abundance in the Galaxy and the relative ease of detecting Earth-sized worlds within their narrower habitable zones. Yet, these low-mass stars can emit high-energy radiation that may gradually erode planetary atmospheres, raising concerns about long-term habitability. TOI-700, a relatively quiescent M dwarf that hosts four known planets, stands out due to its Earth-sized TOI-700 d in the star's habitable zone. Here, we assess whether a habitable environment can be sustained on TOI-700 d by analyzing different UV flux levels and atmospheric pressures. We focus on two atmospheric scenarios, one analogous to the Archean Earth and another representing a modern Earth-like environment, using a 1D climate-photochemistry model. Our results indicate that all simulated cases can maintain temperatures compatible with liquid water on the surface. However, the dominant photochemical pathways differ substantially with UV levels: under low-UV conditions, haze formation in the Archean-like atmospheres provides the main UV shielding, whereas under intensified UV, ozone production in the modern Earth-like atmospheres can protect the surface from harmful doses. Interestingly, although haze can impede the detection of certain biosignatures, such as CH4, CO2 and O2, it also enhances the overall atmospheric signal by increasing scattering and transit depth, potentially aiding in revealing the presence of an atmosphere. These findings underscore the dual role of hazes as both a challenge for biosignature detection and a potential protection of surface habitability. (AU) | |
| Processo FAPESP: | 21/14897-9 - Atmosferas de exoplanetas: o impacto da atividade estelar no espectro de transmissão |
| Beneficiário: | Viktor Yuri Doná Sumida |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |
| Processo FAPESP: | 24/03652-3 - Parâmetro de Impacto e Atividade Estelar - Implicações para Espectroscopia de Transmissão Exoplanetária: Análise prospectiva sobre futuros alvos do telescópio espacial ARIEL; e uma investigação detalhada da lacuna no raio de planetas pequenos |
| Beneficiário: | Viktor Yuri Doná Sumida |
| Modalidade de apoio: | Bolsas no Exterior - Estágio de Pesquisa - Doutorado |
| Processo FAPESP: | 21/02120-0 - Investigação de fenômenos de astrofísica de plasmas e altas energias, instalação do ASTRI-Mini Array & construção dos telescópios de tamanho pequeno do Cherenkov Telescope Array (CTA-SSTs) |
| Beneficiário: | Elisabete Maria de Gouveia Dal Pino |
| Modalidade de apoio: | Auxílio à Pesquisa - Projetos Especiais |
| Processo FAPESP: | 18/04055-8 - Espectroscopia de alta precisão: das primeiras estrelas aos planetas |
| Beneficiário: | Jorge Luis Melendez Moreno |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |