Physics of low mass stars, brown dwarfs and extrasolar planets

In this thesis, we studied a range of problems linked to sub-stellar objects, using principally, two codes developed in the Lyon group, the phoenix atmosphereradiative transfer code and the Lyon stellar evolution code. We studied the effect of accretion on the properties of young low mass stars and...

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Detalles Bibliográficos
Autor: Gallardo-Narbona, José
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2007
País:Chile
Idioma:inglés
OAI Identifier:oai:repositorio.anid.cl:10533/180507
Acceso en línea:http://creativecommons.org/licenses/by-nc-nd/3.0/cl/
https://hdl.handle.net/10533/180507
Access Level:acceso abierto
Descripción
Sumario:In this thesis, we studied a range of problems linked to sub-stellar objects, using principally, two codes developed in the Lyon group, the phoenix atmosphereradiative transfer code and the Lyon stellar evolution code. We studied the effect of accretion on the properties of young low mass stars and brown dwarfs; we analyzed the most recent opacity line lists of molecules present in the atmospheres of M-dwarf stars, with the aim to better describe observed spectra in the optical and near-IR wavelengths and the photometry of LMSs. Moreover, we studied the mass-radius and Teff-radius relationships in low mass star eclipsing binary systems in order to understand the discrepancies between current models andobservational data. We also developed a fast technique to pre-select the mostpromising extrasolar planet candidates from transits surveys for follow-up observations.Furthermore, we carried out observations of an exoplanet host star inoptical and infrared bands and we did a bibliographic work, focusing our intereston the lithium abundance in stars as a possible tracer indicating the presence of a planets companion.