HR diagram positions of K0V stars HD 110067 and its virtual twin, σ Dra. They both coincide with e.g. a 0.8 Gyr-old model of a 0.85 M_⊙ MESA evolution track and a 6.8-Gyr model on an evolution track with 0.80 M_⊙, using here a metallicity of [Fe/H] = −0.16. Solid lines indicate stable, well-modelled phases, while dashed lines indicate transitions, uncertainties, or complex phenomena in the star’s evolution.