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Centro de Astrofísica da Universidade do Porto

Abundance analysis of four members of the metal-rich open cluster NGC 6253

M. Montalto, N. C. Santos, S. Villanova, G. Pace, G. Piotto, S. Desidera, F. De Marchi, L. Pasquini, I. Saviane

Abstract
We report on VLT/UVES high-resolution spectra of four members of the old metal-rich open cluster NGC 6253: a main-sequence star, two red-clump stars and a blue straggler. We performed equivalent width analysis and derived Fe, Si, Ca, Ti, Cr and Ni abundances as well as abundance ratios. For our main-sequence star, we obtained a metallicity of [Fe/H] = +0.26±0.11 (rms), whereas for the two giants we found that our metallicities are on average +0.19±0.13 (rms), lower than what was determined for the same stars in previous studies. We also found that, within the uncertainties, the abundance ratios of a and iron-peak elements match those in the solar surroundings, with the possible exception of Si in two giant stars in our sample.

Keywords
techniques: spectroscopic – stars: abundances – open clusters and associations: individual: NGC 6253

Notes
Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere (ESO) in Paranal during programme 381.C-0270(A).

Monthly Notices of the Royal Astronomical Society
Volume 423, Page 3039
July 2012

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