A small survey of the magnetic fields of planet-host stars
Abstract
Using spectropolarimetry, we investigate the large-scale magnetic topologies of stars hosting close-in exoplanets. A small survey of 10 stars has been done with the twin instruments Télescope Bernard Lyot /NARVAL and Canada-France-Hawaii Telescope/ESPaDOnS between 2006 and 2011. Each target consists of circular polarization observations covering 7-22 d. For each of the seven targets in which a magnetic field was detected, we reconstructed the magnetic field topology using Zeeman-Doppler imaging. Otherwise, a detection limit has been estimated. Three new epochs of observations of τ Boo are presented, which confirm magnetic polarity reversal. We estimate that the cycle period is 2 yr, but recall that a shorter period of 240 d cannot still be ruled out. The result of our survey is compared to the global picture of stellar magnetic field properties in the mass-rotation diagram. The comparison shows that these giant planet-host stars tend to have similar magnetic field topologies to stars without detected hot Jupiters. This needs to be confirmed with a larger sample of stars.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- October 2013
- DOI:
- 10.1093/mnras/stt1386
- arXiv:
- arXiv:1307.6091
- Bibcode:
- 2013MNRAS.435.1451F
- Keywords:
-
- techniques: polarimetric;
- stars: activity;
- stars: individual;
- stars: magnetic field;
- planetary systems;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted for publication in Monthly Notices of The Royal Astronomical Society