Oxygen, α-element and iron abundance distributions in the inner part of the Galactic thin disc

We derived elemental abundances in 27 Cepheids, the great majority situated within a zone of Galactocentric distances ranging from 5 to 7 kpc. One star of our sample, SU Sct, has a Galactocentric distance of about 3 kpc, and thus falls in a poorly investigated region of the inner thin disc. Our new results, combined with data on abundances in the very central part of our Galaxy taken from the literature, show that iron, magnesium, silicon, sulphur, calcium and titanium local thermodynamic equilibrium abundance radial distributions, as well as non-local thermodynamic equilibrium distribution of oxygen reveal a plateau-like structure or even positive abundance gradient in the region extending from the Galactic Centre to about 5 kpc.