Measuring precise radial velocities on individual spectral lines. I. Validation of the method and application to mitigate stellar activity

Understand

Stellar activity is the main limitation to the detection of Earth-twins using the RV technique.

• Despite many efforts in trying to mitigate the effect of stellar activity using empirical and statistical techniques, it seems that we are facing an obstacle that will be extremely difficult to overcome using current techniques.
• In this paper, we investigate a novel approach to derive precise RVs considering the wealth of information present in high-resolution spectra.
• This new method consists in building a master spectrum from all observations and measure the RVs of each spectral line in a spectrum relative to it.