Context: Straight-forward derivation of planetary parameters can only be achieved in transiting planetary systems. However, planetary attributes such as radius and mass strongly depend on stellar host parameters. Discovering a transit host star to be multiple leads to a necessary revision of the derived stellar and planetary parameters.
Aims: Based on our observations of 14 transiting exoplanet hosts, we derive parameters of the individual components of three transit host stars (
Methods: High-resolution “Lucky Imaging” with AstraLux at the 2.2 m Calar Alto telescope provided near diffraction limited images in i' and z' passbands. These results have been combined with existing planetary data in order to recalibrate planetary attributes.
Results: Despite the faintness (∆mag ~ 4) of the discovered stellar companions to TrES-2, TrES-4, and WASP-2, light-curve deduced parameters change by up to more than 1σ. We discuss a possible relation between binary separation and planetary properties, which - if confirmed - could hint at the influence of binarity on the planet formation process.
Astronomy and Astrophysics
- Pub Date:
- May 2009
- instrumentation: high angular resolution;
- stars: binaries: general;
- planets and satellites: general;
- stars: individual: WASP-2;
- stars: individual: TrES-2;
- stars: individual: TrES-4;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics
- 9 pages, 3 Figures. Accepted by A&