CHEMICAL COMPOSITION AND ATMOSPHERE PARAMETERS OF THE DOUBLE-MODE CEPHEID U TRA

• Published in: Odessa astronomical publications Vol. 26; no. 1; pp. 127 - 130
• Main Authors: I. A. Usenko, A. Yu. Knyazev, L. N. Berdnikov, V. V. Kravtsov
• Format: Journal Article
• Language: English
• Published: Odessa I. I. Mechnykov National University 01.11.2013
• ISSN: 1810-4215
• DOI: 10.18524/1810-4215.2013.26.82357

Four high-resolution spectra of the doble-mode Cepheid UTrA have been obtained during its pulsational period. For the first time, we obtained accurate atmosphere parameters and the chemical abundance of a number of elements, in particular of sodium, magnesium, and aluminium. We estimated the mean Teff =608529K, logg=2.000.15, and Vt =3.900.25kms 1. A deficit of carbon ([C=H] =–0.350.23dex), over abundance of both sodium  ([Na=H]=+0.150.25dex) and aluminium ([Al=H] =+0.300.32dex) are typical for Cepheids passing through the first dredge-upphase. The abundance of iron ([Fe=H]=+0.010.15dex) is very close to the solar one. Moreover, we find that -elements, those of Fe-group, as well as ”light” - and ”heavy”-, s- and r- process elements, all of them have abundances close  to solar values, too, excepting may be severale lements with slight enhance or deficit.