J/A+A/305/551 J/A+A/305/551 Chemical composition of the s-Cepheids S M Andrievsky V V Kovtyukh I A Usenko Astron. Astrophys. 305 551 1996 1996A&A...305..551A Abundances Stars, variable Cepheids stars: abundances stars: evolution On the base of photographic, Reticon and CCD spectra analysis we have derived the abundances for 8 s-Cepheids and V1162 Aql (before classified as s-Cepheid). The following results have been obtained: 1) all Cepheids (excluding only EU Tau) have solar-like abundances of {alpha}- and iron-group elements, 2) Na is over abundant for all program stars, 3) the carbon deficiency found for EU Tau, DT Cyg, V440 Per and nitrogen overabundance (DT Cyg), show that these s-Cepheids are not crossing the instability strip for first time, 4) s-process elements are slightly enhanced in the program stars, 5) V1162 Aql does not show any changes in C and N abundances. The most plausible explanation is that this star is a normal Cepheid (C{delta}), but it is firstly crossing the instability strip toward the giant branch. This conclusion is also confirmed by its position on the evolutionary diagram.

V440 PerHD 1466202 23 51.7+55 21 53 SU CasHD 1746302 51 58.7+68 53 19 SZ TauHD 2926004 37 14.7+18 32 35 EU TauHD 3832105 45 40.5+18 39 25 Y OphHD 16271417 52 38.6-06 08 37 FF AqlHD 17615518 58 14.6+17 21 40 DT CygHD 20107821 06 30.1+31 11 05 V1334 CygHD 20315621 19 22.1+38 14 15

Element Element --- [X/H]1 Abundance of the element for phase=0.477 Sun e_[X/H]1 Error on abundance Sun o_[X/H]1 Number of observations --- [X/H]2 Abundance of the element for phase=0.627 Sun e_[X/H]2 Error on abundance Sun o_[X/H]2 Number of observations --- [X/H]LL81 Abundance of the element from Luck and Lambert 1981 Sun Element Element --- [X/H]1 Abundance of the element for phase=0.297 Sun e_[X/H]1 Error on abundance Sun o_[X/H]1 Number of observations --- [X/H]2 Abundance of the element for phase=0.323 Sun e_[X/H]2 Error on abundance Sun o_[X/H]2 Number of observations --- [X/H]3 Abundance of the element for phase=0.758 Sun e_[X/H]3 Error on abundance Sun o_[X/H]3 Number of observations --- Element Element --- [X/H]1 Abundance of the element for phase=0.155 Sun e_[X/H]1 Error on abundance Sun o_[X/H]1 Number of observations --- [X/H]2 Abundance of the element for phase=0.774 Sun e_[X/H]2 Error on abundance Sun o_[X/H]2 Number of observations --- [X/H]3 Abundance of the element for phase=0.814 Sun e_[X/H]3 Error on abundance Sun o_[X/H]3 Number of observations --- [X/H]LL81 Abundance of the element from Luck and Lambert 1981 Sun Element Element --- [X/H]1 Abundance of the element for phase=0.119 Sun e_[X/H]1 Error on abundance Sun o_[X/H]1 Number of observations --- [X/H]2 Abundance of the element for phase=0.501 Sun e_[X/H]2 Error on abundance Sun o_[X/H]2 Number of observations --- Element Element --- [X/H] Abundance of the element Sun e_[X/H] Error on abundance Sun o_[X/H] Number of observations --- Element Element --- [X/H]1 Abundance of the element for phase=0.780 Sun e_[X/H]1 Error on abundance Sun o_[X/H]1 Number of observations --- [X/H]2 Abundance of the element for phase=0.864 Sun e_[X/H]2 Error on abundance Sun o_[X/H]2 Number of observations --- Element Element --- [X/H]1 Abundance of the element for phase=0.080 Sun e_[X/H]1 Error on abundance Sun o_[X/H]1 Number of observations --- [X/H]2 Abundance of the element for phase=0.218 Sun e_[X/H]2 Error on abundance Sun o_[X/H]2 Number of observations --- [X/H]3 Abundance of the element for phase=0.374 Sun e_[X/H]3 Error on abundance Sun o_[X/H]3 Number of observations --- [X/H]4 Abundance of the element for phase=0.385 Sun e_[X/H]4 Error on abundance Sun o_[X/H]4 Number of observations --- [X/H]L82 Abundance of the element from Luck 1982 Sun tables.texLaTeX version of tables Simona Mei CDS 1995Jun07 J_A+A_305_551.xml