The ultra-metal-deficient (Population III?) red giant CD 38.245 deg

The authors present photometric and high-resolution spectroscopic data on the ultra-metal-deficient red giant CD -38°245. A model atmosphere analysis yields the parameters effective temperature, surface gravity and the element abundances. As a check the same procedures were applied to the well studied Population II red giant HD 2796. CD -38°245 has [Fe/H] = -4.5, and is the most metal-deficient astronomical object currently known. The authors suggest that CD -38°245 is an extreme Population II object, as opposed to its being a member of a new population.