The complete 8D parameter-space of the galaxy’s metal-poor stellar population (6D velocities, chemistry, and age) can be used to investigate its formation and chemical evolution. However, estimating stellar ages is one of the most difficult problems in astrophysics. This scenario is now changing, as it becomes possible to obtain stellar ages by adding solar-like oscillations to our modelling. By combining individual stellar data: photometry spanning from the UV to the IR, stellar chemistry from high-resolution, high S/N, spectra, galactic extinction, astrometric information, and seismic data (solar-like oscillations), we can now precisely determine the relative ages of individual stars. However, most of the current developments in this area are focused on stars of metallicities higher than [Fe/H]>-1.5. We used the mid-infrared metal-poor star selection of Schlaufman et al. (2014), to select 9 K2 stars, including a star in the M4 GC, with published asterosismic data, and observed them with the high-resolution MIKE spectrograph. We analyzed these red giants with the most current analysis technique, combining all photometric, astrometric, spectroscopic, and seismic data to infer the best possible relative ages of these metal-poor stars (-2.7<[Fe/H]<-1.3). Our analysis correctly retrieves the metallicity and age of the M4 Gobular Cluster, and our technique will allow us to link the relative ages of the old metal-poor population with the chemo-dynamical history of the Milky Way.
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