Description
Two projects from solar and stellar spectroscopy relevant for stellar convection will be presented: 1) the CARMENES survey for exoplanets around M dwarfs observed 300 stars for more than five years. The entire data set was used to produce high-S/N spectra of the stars from which average surface magnetic fields were measured. The stars cover a large parameter range showing scaling relations relevant for convection and stellar dynamos. 2) In Göttingen, we are operating a 50cm solar telescope with a broadband high-resolution spectrometer that we use for developing spectral calibration techniques. The spectrometer provides unprecedented frequency accuracy with which we can determine line-by-line absolute Doppler shifts. We measured the depth-dependent convective blueshift across the solar surface (at different limb positions) providing useful constraints for solar convection and detailed empirical information about line profiles from the solar atmosphere seen under different projection angles.
