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http://hdl.handle.net/1843/60352| Tipo: | Artigo de Periódico |
| Título: | Is the primary CoRoT target HD 43587 under a Maunder minimum phase? |
| Autor(es): | Rafael Ramon Ferreira Rafaella Barbosa Matthieu Sébastien Castro Gustavo Andres Guerrero Eraso Leandro de Almeida Patrick Boumier José Dias do Nascimento Júnior |
| Resumo: | CONTEXT. One of the most enigmatic phenomena related to solar activity is the so-called Maunder minimum phase. It consists in the lowest sunspot count ever registered for the Sun and has not been confirmed for other stars to date. Since the spectroscopic observations of stellar activity at the Mount Wilson Observatory, the solar analog HD 43587 has shown a very low and apparently invariant activity level, which makes it a Maunder minimum candidate. AIMS. We aim to analyze the chromospheric activity evolution of HD 43587 and its evolutive status, with the intention of unraveling the reasons for this low and flat activity. METHODS. We used an activity measurements dataset available in the literature, and computed the S -index from HARPS and NARVAL spectra to infer a cycle period. Additionally, we analyzed the CoRoT light curve of HD 43587, and applied gyrochronology and activity calibrations to determine its rotation period. Finally, based on an evolutionary model and the inferred rotation period, we used the EULAG-MHD code to perform global MHD simulations of HD 43587 to get some insight into its dynamo process. RESULTS. We confirm the almost flat activity profile, with a cycle period Pcyc = 10.44 ± 3.03 yr deduced from the S -index time series, and a long-term trend that might be a period of more than 50 yr. It was impossible to define a rotation period from the light curve, however gyrochronology and activity calibrations allow us to infer an indirect estimate of Prot = 22.6 ± 1.9 d. Furthermore, the MHD simulations confirm an oscillatory dynamo with a cycle period in good agreement with the observations and a low level of surface magnetic activity. CONCLUSIONS. We conclude that this object might be experiencing a “natural” decrease in magnetic activity as a consequence of its age. Nevertheless, the possibility that HD 43587 is in a Maunder minimum phase cannot be ruled out. |
| Assunto: | Estrelas Campos magnéticos |
| Idioma: | eng |
| País: | Brasil |
| Editor: | Universidade Federal de Minas Gerais |
| Sigla da Instituição: | UFMG |
| Departamento: | ICX - DEPARTAMENTO DE FÍSICA |
| Tipo de Acesso: | Acesso Aberto |
| Identificador DOI: | https://doi.org/10.1051/0004-6361/201937219 |
| URI: | http://hdl.handle.net/1843/60352 |
| Data do documento: | 2020 |
| metadata.dc.url.externa: | https://www.aanda.org/articles/aa/abs/2020/08/aa37219-19/aa37219-19.html |
| metadata.dc.relation.ispartof: | Astronomy & Astrophysics |
| Aparece nas coleções: | Artigo de Periódico |
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| Arquivo | Descrição | Tamanho | Formato | |
|---|---|---|---|---|
| Is the primary CoRoT target HD 43587 under a Maunder minimum phase.pdf | 4.09 MB | Adobe PDF | Visualizar/Abrir |
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