Hertzsprung-Russell diagram of all stars in the CRIRES-POP library. Logarithm of stellar luminosity in solar units is plotted against spectral type. Luminosities were taken from the literature, primarily McDonald et al. (2012), but also Anderson & Francis (2012), Jofré et al. (2015), and Newton et al. (2015). The data for several stars is somewhat uncertain; we found spectral type to be more homogeneous and reliable than the literature T_eff determinations, and some published luminosities were at odds with the accepted luminosity class. In these few cases we have moved the star to a luminosity more representative of its accepted luminosity class. Hence this diagram is intended purely for illustrative purposes, to give a visual representation of the span of the CRIRES-POP library. Included in each CRIRES-POP atlas will be updated stellar properties, which will allow us to improve this diagram as results are published.