Coordinated X-ray and Optical observations of Star-Planet Interaction in HD 17156
Abstract
The large number of close-in Jupiter-size exoplanets prompts the question whether star-planet interaction (SPI) effects can be detected. We focused our attention on the system HD 17156, having a Jupiter-mass planet in a very eccentric orbit. Here we present results of the XMM-Newton observations and of a five months coordinated optical campaign with the HARPS-N spectrograph. We observed HD 17156 with XMM-Newton when the planet was approaching the apoastron and then at the following periastron passage, quasi simultaneously with HARPS-N. We obtained a clear () X-ray detection only at the periastron visit, accompanied by a significant increase of the chromospheric index. We discuss two possible scenarios for the activity enhancement: magnetic reconnection and flaring or accretion onto the star of material tidally stripped from the planet. In any case, this is possibly the first evidence of a magnetic SPI effect caught in action.
Keywords
Cite
@article{arxiv.1509.00662,
title = {Coordinated X-ray and Optical observations of Star-Planet Interaction in HD 17156},
author = {A. Maggio and I. Pillitteri and G. Scandariato and A. F. Lanza and S. Sciortino and F. Borsa and A. S. Bonomo and R. Claudi and E. Covino and S. Desidera and R. Gratton and G. Micela and I. Pagano and G. Piotto and A. Sozzetti and R. Cosentino and J. Maldonado},
journal= {arXiv preprint arXiv:1509.00662},
year = {2015}
}