Exoplanet detections: how hydro-dynamical simulations of the stellar noise could help us to control the false alarm rate
With the extremely high precision of the recent spectrographs, the main barrier to detect small extrasolar planets by the radial velocity (RV) technique is the noise coming from the host star activity: spots and plages at the surface, convective process and stellar oscillations (see Fig. 1). The underlying difficulty for the detection of sinusoids (i.e. RV planet signatures) is to control the true significance level of the test outcome as the stellar noise is colored (i.e. frequency dependent) with unknown statistics. This is critical since the signal-to-noise ratio is low. The stellar noise can also mimic or even hide small planet signatures and create ambiguous detections. In this work, we focus on enquiring the contribution of convective process, which induces a permanent correlated stellar "jitter" with magnitude at the level of the smallest planet signatures, and investigating whether realistic time-dependent hydrodynamic (HD) simulations of the stellar convection could improve the control of the significance assigned to planet detections.