A coordinated optical and X-ray spectroscopic campaign on HD 179949: searching for planet-induced chromospheric and coronal activity
Abstract
Context.
Aims: A long-term monitoring of the magnetic activity of
Methods: In 2009 we performed a simultaneous optical and X-ray spectroscopic campaign to monitor the magnetic activity of
Results: A detailed analysis of the flux in the cores of the Ca ii H&K lines and a similar study of the X-ray photometry shows evidence of source variability, including one flare. The analysis of the time series of chromospheric data indicates a modulation with a ~11 days period, compatible with the stellar rotation period at high latitudes. Instead, the X-ray light curve suggests a signal with a period of ~4 days, consistent with the presence of two active regions on opposite hemispheres.
Conclusions: The observed variability can be explained, most likely, as due to rotational modulation and to intrinsic evolution of chromospheric and coronal activity. There is no clear signature related to the orbital motion of the planet, but the possibility that just a fraction of the chromospheric and coronal variability is modulated with the orbital period of the planet, or the stellar-planet beat period, cannot be excluded. We conclude that any effect due to the presence of the planet is difficult to disentangle.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 2013
- DOI:
- 10.1051/0004-6361/201219875
- arXiv:
- arXiv:1301.7748
- Bibcode:
- 2013A&A...552A...7S
- Keywords:
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- planet-star interactions;
- stars: activity;
- stars: magnetic field;
- stars: solar-type;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- doi:10.1051/0004-6361/201219875