Extremely Low-Metallicity Stars in the Classical Dwarf Galaxies

After careful re-analysis of Ca II triplet calibration at low-metallicity, the classical satellites around the Milky Way are found not to be devoided of extremely low-metallicity stars and their (extremely) metal-poor tails are predicted to be much more in agreement with the Milky Way halo. A first follow-up study of 7 extremely metal-poor candidates within the Sculptor dwarf galaxy with X-shooter on ESO/VLT has further confirmed the new metallicity calibration for the Ca IT triplet at low metallicities and provides abundances for many other elements in these stars. We will discuss the results of this study and show a comparison with the Galactic extremely metal-poor stars.