naa a22 4500 510790119 CHVBK 20180411083316.0 cr unu---uuuuu 180411e20131201xx s 000 0 eng 10.1134/S1063773713120050 doi (NATIONALLICENCE)springer-10.1134/S1063773713120050 Properties of the population of classical Cepheids in the Galaxy [Elektronische Daten] [V. Marsakov, V. Koval', V. Kovtyukh, T. Mishenina] Based on our compiled catalogue of positions, velocities, ages, and abundances of nine chemical elements for 221 classical Cepheids, we analyze the dependences of the relative abundances of α-elements as well as rapid and slow neutron capture elements on metallicity, space velocity components, and Galactocentric distance. We have found that the relative abundances of all elements in Cepheids do not depend on velocity but increase with Galactocentric distance and decrease with increasing metallicity, just as in thin-disk dwarfs and giants. In Cepheids, however, the [α/Fe]-[Fe/H] relation lies below, while the [r/Fe]-[Fe/H] and [s/Fe]-[Fe/H] relations lie above the analogous sequences for dwarfs and giants. We hypothesize that upon reaching a nearly solar metallicity in the interstellar medium of the thin disk, the most massive stars ceased to explode as type II supernovae, which mostly enriched the interstellar medium with α-elements. As a result, an underabundance of α-elements and a slight overabundance of r-process elements, which are ejected into the interstellar medium by less massive (8-10 M ⊙) type II supernovae, were formed in the next generations of stars. The overabundance of s-process elements in Cepheids can be explained by the fact that some of the s-elements were produced in the weak s-process in the interiors of massive stars, which may be able to eject the upper parts of their envelopes even without any explosion like asymptotic giant branch stars. And since such massive stars, exploding as type II supernovae, also enriched the interstellar medium with a considerable amount of iron atoms, the [s/Fe] ratios (along with [r/Fe]) in the next generations of stars must be higher in their absence. Pleiades Publishing, Inc., 2013 stellar populations nationallicence field Cepheids nationallicence chemical composition nationallicence Galaxy nationallicence Marsakov V. Southern Federal University, Bolshaya Sadovaya ul. 105/42, 344006, Rostov-on-Don, Russia aut Koval' V. Southern Federal University, Bolshaya Sadovaya ul. 105/42, 344006, Rostov-on-Don, Russia aut Kovtyukh V. Astronomical Observatory, Odessa National University, Odessa, Ukraine aut Mishenina T. Astronomical Observatory, Odessa National University, Odessa, Ukraine aut Astronomy Letters Springer US; http://www.springer-ny.com 39/12(2013-12-01), 851-865 1063-7737 39:12<851 2013 39 11443 https://doi.org/10.1134/S1063773713120050 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S1063773713120050 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Marsakov V. Southern Federal University, Bolshaya Sadovaya ul. 105/42, 344006, Rostov-on-Don, Russia aut NATIONALLICENCE 700 1- Koval' V. Southern Federal University, Bolshaya Sadovaya ul. 105/42, 344006, Rostov-on-Don, Russia aut NATIONALLICENCE 700 1- Kovtyukh V. Astronomical Observatory, Odessa National University, Odessa, Ukraine aut NATIONALLICENCE 700 1- Mishenina T. Astronomical Observatory, Odessa National University, Odessa, Ukraine aut NATIONALLICENCE 773 0- Astronomy Letters Springer US; http://www.springer-ny.com 39/12(2013-12-01), 851-865 1063-7737 39:12<851 2013 39 11443 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer