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J/ApJ/479/427       Abundance Analyses of RV Tauri Variables (Gonzalez+ 1997)

Abundance Analyses of the Field RV Tauri Variables: EP Lyrae, DY Orionis, AR Puppis, and R Sagittae Gonzalez G., Lambert D.L., Giridhar S. <Astrophys. J. 479, 427 (1997)> =1997ApJ...479..427G
ADC_Keywords: Stars, variable ; Abundances ; Stars, horizontal branch Keywords: stars: abundances - stars: AGB and post-AGB - stars: variables: other (RV Tauri) Abstract: Analyses of the photospheric compositions of the four field RV Tauri stars, EP Lyr, DY Ori, AR Pup, and R Sge, indicate that to varying degrees they have experienced fractionation processes that have preferentially depleted their atmospheres of elements with high condensation temperatures. The depletion, as indicated by, for instance, [S/Fe], is greatest for DY Ori, [S/Fe]=2.5, and least for R Sge, [S/Fe]=0.9. The initial composition, presumably indicated by the sulfur abundance, was nearly solar for AR Pup, R Sge, and DY Ori, while it was about 0.6--- less than solar for EP Lyr. This implies that the RV Tauri stars as a group may not be as metal-poor as previously thought---they are instead ``metal-depleted''. The field RV Tauri's are not halo stars, but probably belong to the thick disk. This brings to seven the number of type II Cepheids that show such a trend; the other three are IW Car and V1 in omega Cen, RV Tauri stars, and ST Pup, a W Virginis star. The 12C/13C ratios for EP Lyr and DY Ori are 9±1 and 6±3, respectively, indicating that CN-cycled material has been mixed with their surface layers. This is consistent with the general consensus that RV Tau stars are in a post-AGB evolutionary stage. There is also evidence that EP Lyr has a stellar mass companion, but additional observations are required to calculate an orbit; hence, EP Lyr could be a link to the group of metal-depleted, high-latitude A-F supergiants, all of which are binaries. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 19 18 19.4 +27 51 03 EP Lyr 20 14 03.7 +16 43 35 R Sge = HD 192388 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3 68 211 Individual abundance results for EP Lyr table3.tex 64 257 AASTeX version of table3 table6 76 112 Individual abundance results for R Sge table6.tex 75 153 AASTeX version of table6
Byte-by-byte Description of file: table3
Bytes Format Units Label Explanations
1- 5 A5 --- Ion Atomic species 7- 11 F5.2 --- log(Eps0) Solar abundance for the ion 13- 19 F7.2 0.1nm lambda Wavelength 21- 25 F5.2 eV EP Low energy potential 27- 32 F6.2 --- log(gf) log of oscillator strength 35- 39 F5.1 10-4nm EW1 ? Equivalent width, 1994 June 25-27 41- 44 F4.2 --- log(Eps1) ? Abundance at lambda, 1994 June 25-27 47- 51 F5.1 10-4nm EW2 ? Equivalent width, 1995 June 10&12 53- 57 F5.2 --- log(Eps2) ? Abundance at lambda, 1995 June 10&12 60- 62 I3 10-4nm EW3 ? Equivalent width, 1996 Mar 3 64- 68 F5.2 --- log(Eps3) ? Abundance at lambda, 1996 Mar 3
Byte-by-byte Description of file: table6
Bytes Format Units Label Explanations
1- 5 A5 --- Ion Atomic species 7- 11 F5.2 --- log(Eps0) Solar abundance for the ion 13- 19 F7.2 0.1nm lambda Wavelength 21- 25 F5.2 eV EP Low energy potential 27- 32 F6.2 --- log(gf) log of oscillator strength 35- 37 I3 10-4nm EW1 ? Equivalent width, 1992 May 22 39- 43 F5.2 --- log(Eps1) ? Abundance at lambda, 1992 May 22 46- 48 I3 10-4nm EW2 ? Equivalent width, 1994 June 24 50- 54 F5.2 --- log(Eps2) ? Abundance at lambda, 1994 June 24 57- 59 I3 10-4nm EW3 ? Equivalent width, 1994 July 29 61- 65 F5.2 --- log(Eps3) ? Abundance at lambda, 1994 July 29 68- 70 I3 10-4nm EW4 ? Equivalent width, 1995 June 12 72- 76 F5.2 --- log(Eps4) ? Abundance at lambda, 1995 June 12
Origin: AAS CD-ROM series, Volume 8, 1997 Lee E. Brotzman [ADS] 06-May-97
(End) [CDS] 04-Jul-1997
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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