CoRoT-18 b: analysis of high-precision transit light curves with starspot features

When a planet occults a spotty area on a stellar surface, the flux increases and a characteristic feature in a light curve - a bump - is observed. Among the planets detected by the CoRoT-mission CoRoT-18 is especially interesting as it exhibited spot crossings that we have analyzed in detail. We use...

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Detalles Bibliográficos
Autores: Raetz, St., Heras, A.M., Gondoin, P., Fernández, Matilde, Casanova, Víctor, Schmidt, T. O. B., MacIejewski, G.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/196834
Acceso en línea:http://hdl.handle.net/10261/196834
Access Level:acceso abierto
Palabra clave:Planetary systems
Planets and satellites: individual: CoRoT-18 b
Stars: individual: CoRoT-18
Descripción
Sumario:When a planet occults a spotty area on a stellar surface, the flux increases and a characteristic feature in a light curve - a bump - is observed. Among the planets detected by the CoRoT-mission CoRoT-18 is especially interesting as it exhibited spot crossings that we have analyzed in detail. We used four ground-based observations obtained at a 1.5-m telescope in Spain and the 13 available CoRoT-transits to refine and constrain stellar, planetary and geometrical parameters of the system. We found that the derived physical properties slightly deviate from the previously published values, most likely due to the different treatment of the stellar activity. Following of a spot over several transits enabled us to measure the stellar rotation period and the spin-orbit alignment. Our derived values of Prot = 5.19±0.03 d and λ = 6±13° are in agreement with the literature values that were obtained with other methods. Although we cannot exclude a very old age for CoRoT-18, our observations support the young star hypothesis and, hence, yield constraints on the time-scale of planet formation and migration. © 2019 Copernicus Foundation for Polish Astronomy. All rights reserved.