dc.contributor.author |
Giridhar, S |
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dc.contributor.author |
Lambert, D. L |
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dc.contributor.author |
Gonzalez, G |
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dc.date.accessioned |
2008-08-14T09:44:27Z |
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dc.date.available |
2008-08-14T09:44:27Z |
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dc.date.issued |
1998-12 |
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dc.identifier.citation |
The Astrophysical Journal, Vol. 509, No. 1, pp. 366 - 378 |
en |
dc.identifier.issn |
0004 - 637x |
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dc.identifier.uri |
http://hdl.handle.net/2248/3131 |
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dc.description.abstract |
Abundance analyses are presented and discussed for five RV Tauri variables. Three stars-DS Aqr, V360 Cyg, and V453 Oph-are RV C stars by spectroscopic classification, i.e., metal lines are weak. They are shown to be metal poor with [Fe/H] from -1.0 to -2.2 with normal relative abundances of other elements. By contrast, AD Aql and AC Her are RV B stars with an odd abundance pattern: elements that condense into grains at a high temperatures are underabundant (i.e., [Fe/H] = -2.1 for AD Aql) but elements with a low condensation temperatures are much less underabundant (i.e., [S/H] = 0.0 and [Zn/H] = -0.1 for AD Aql). This abundance pattern is ascribed to a separation of dust and gas in the upper atmosphere of the star. The present analyses with previously published results are used to investigate the systematics of the dust-gas separation in RV Tauri variables. The process is apparently inoperative in stars with an initial metallicity of about [Fe/H] <~ -1.0 RV C stars and similar variables in globular clusters are immune to the dust-gas separation. The process achieves more severe effects in RV B than in RV A stars. The strength of the abundance anomalies attributed to dust-gas separation is not correlated with reported infrared excesses. After correction for the effects of the dust-gas separation, there is no strong evidence from the abundances that evolution along the AGB and experience of the third dredge-up preceded the formation of the majority of the RV Tauri variables. |
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dc.format.extent |
354198 bytes |
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dc.format.mimetype |
application/pdf |
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dc.language.iso |
en |
en |
dc.publisher |
The American Astronomical Society |
en |
dc.relation.uri |
http://www.journals.uchicago.edu/doi/abs/10.1086/306487 |
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dc.subject |
Stars:Circumstellar Matter |
en |
dc.subject |
Stars:Abundances |
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dc.subject |
Stars:Variables |
en |
dc.title |
Abundance Analyses of Field RV Tauri Stars. IV. AD Aquilae, DS Aquarii, V360 Cygni, AC Herculis, and V453 Ophiuchi |
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dc.type |
Article |
en |