TITANS: the metal-poor reference stars

Tracing the history of chemical evolution of the Milky Way requires the determination of chemical abundances in a large assortment of stars with accurate stellar parameters. Nonetheless, the accuracy achieved in the derived astrophysical parameters is still insufficient, mainly because of the paucity of adequate calibrators, particularly in the metal-poor regime ([Fe/H] < -1.0). At present, the prime stellar calibration sample is that of the Gaia benchmark stars. Most of these stars have effective temperature constrained by measurements of their bolometric fluxes and angular diameters. However, only seven of them are metal-poor. To increase this number, we introduce the “Titans metal-poor reference stars”: stars with accurate model-dependent parameters that are "descendants" of the Gaia benchmarks.