Overview of all sample stars’ signal-to-noise ratio (S/N), temperature, and spectral type. Top left: distribution of S/N over spectral type within the sample. The marker size corresponds to the number of observations for that star. The M stars show significantly smaller S/N with median below 300 due to both smaller intrinsic brightness and lower average number of coadded spectra. The dashed, horizontal lines mark S/N values of 100, 200, and 300, motivated by the results from Appendix C.5. Top right: peak S/N for the coadded spectra in the sample. Bottom left: distribution of spectral types within the sample.