Photospheric activity, rotation, and star-planet interaction of the planet-hosting star CoRoT-6

Lanza A.F.; Bonomo A.S.; Pagano I.; Leto G.; Messina S.; Cutispoto G.; Moutou C.; Aigrain S.; Alonso R.; Barge P.; Deleuil M.; Fridlund M.; Silva-Valio A.; Auvergne M.; Baglin A.; Collier Cameron A.

Photospheric activity, rotation, and star-planet interaction of the planet-hosting star CoRoT-6

Tipo

Artigo

Data de publicação

2010

Periódico

Astronomy and Astrophysics

Citações (Scopus)

10

Autores

Lanza A.F.
Bonomo A.S.
Pagano I.
Leto G.
Messina S.
Cutispoto G.
Moutou C.
Aigrain S.
Alonso R.
Barge P.
Deleuil M.
Fridlund M.
Silva-Valio A.
Auvergne M.
Baglin A.
Collier Cameron A.

Resumo

Context. The CoRoT satellite has recently discovered a hot Jupiter that transits across the disc of a F9 main-sequence star called CoRoT-6 with a period of 8.886 days. Aims. We model the photospheric activity of the star and use the maps of the active regions to study stellar differential rotation and the star-planet interaction. Methods. We apply a maximum entropy spot model to fit the optical modulation as observed by CoRoT during a uninterrupted interval of ~ 140 days. Photospheric active regions are assumed to consist of spots and faculae in a fixed proportion with solar-like contrasts. Results. Individual active regions have lifetimes up to 30-40 days. Most of them form and decay within five active longitudes whose different migration rates are attributed to the stellar differential rotation for which a lower limit of ΔΩ/Ω = 0.12 ± 0.02 is obtained. Several active regions show a maximum of activity at a longitude lagging the subplanetary point by ~ 200° with the probability of a chance occurrence being smaller than 1 percent. Conclusions. Our spot modelling indicates that the photospheric activity of CoRoT-6 could be partially modulated by some kind of star-planet magnetic interaction, while an interaction related to tides is highly unlikely because of the weakness of the tidal force. © 2010 ESO.

Assuntos Scopus

Planetary system , stars: activity , stars: individual: CoRoT-6 , stars: late-type , stars: magnetic field , stars: rotation