Astronomy and Astrophysics
Aims: We aim to benchmark the impact of stellar activity on high-precision RV measurements using regular-cadence CARMENES visible and near-infrared observations of the active M3.5 dwarf EV Lac.
Methods: We used the newly developed technique of low-resolution Doppler imaging to determine the centre-of-light, or spot-induced RV component, for eight observational epochs.
Results: We confirm a statistically significant and strong correlation between the independently measured centre-of-light and the chromatic index, which is a measure of the amplitude variation with wavelength of the RVs. We also find circular "closed-loop" relations of several activity indices with RV for a subset of data that covers only several rotation periods. We also investigate the implications of large phase gaps in the periodograms of activity indicators. Finally, by removing the spot-induced RV component we improve the planet-mass sensitivity by a factor of at least three.
Conclusions: We conclude that for active M stars, a regular-cadence observing strategy is the most efficient way to identify and eliminate sources of correlated noise.
Se investigan los procesos que conducen a la formación de estrellas de baja masa, enanas marrones y exoplanetas y caracterizar las propiedades físicas de estos astros en varias etapas evolutivas. Las estrellas de muy baja masa y las enanas marrones son probablemente los objetos más numerosos de nuestra Galaxia, pero no por ello están