Radial velocity time series of EK Eridani

This star was observed with the 1m Hertzsprung SONG telescope at the Observatorio del Teide for two different runs of 8 and 13 nights, respectively, that were separated by about a year. We determined a significant excess of power around {nu}_max_=253+/-3uHz in the first observing run and were able to determine a large separation, {Delta}_{nu}_=16.430+/-22uHz.

No significant excess of power was instead detected in a subsequent SONG observing season, as also supported by our analysis of the simultaneous TESS photometric observations. We propose a new amplitude-luminosity relation in order to account for the missing power in the power spectrum. Based on the evolutionary stage of this object, we argue that a standard {alpha}^2^{OMEGA} dynamo cannot be excluded as the possible origin for the observed magnetic field.