| Texto completo | |
| Autor(es): |
Valio, Adriana
;
Araujo, Alexandre
;
Menezes, Fabian
Número total de Autores: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ASTROPHYSICAL JOURNAL; v. 972, n. 1, p. 9-pg., 2024-09-01. |
| Resumo | |
While direct magnetic field measurements are rare for slowly rotating stars, spots observed during planetary transits provide a potential indicator of magnetic activity on stellar surfaces. Moreover, the rotation of the stellar surface can be probed by monitoring the spots' position with time in subsequent transits. This study investigates the dynamic interplay of rotational shear and stellar rotation rate in six stars of spectral types F to M, all hosting exoplanets observed by the CoRoT space mission, except for one binary star from Kepler. The analysis, facilitated by the ECLIPSE code, unveils the physical properties of stellar spots, including radius, intensity, temperature, and position. The five CoRoT stars exhibit spot characteristics consistent with those observed in solar type stars. The determination of a spot longitude during different transits allows for the inference of the star's differential rotation profile, revealing a decreasing trend of rotational shear with the mean stellar rotation period, given by Delta Omega proportional to P<overline>(-0.9) . This implies that, at least for slow rotators (mean rotation period >5 days), as stars age, their differential rotation decreases. Additionally, the six stars analyzed here seem to fall into two categories, according to their spot flux deficit: those with Delta F (spot) > 0.005 and those with Delta F (spot)< 0.002. (AU) | |
| 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 |
| 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 |