Subgiant CH stars. II - Chemical compositions and the evolutionary connection with barium stars

Luck, R. E.; Bond, Howard E.

doi:10.1086/191615

Cited by 138 publications

(170 citation statements)

References 0 publications

Supporting

Mentioning

154

Contrasting

Order By: Relevance

“…This star was previously analyzed by Luck & Bond (1991). Our results are in good agreement with theirs.…”

Section: Hr 5058supporting

confidence: 92%

“…Table 1 presents the literature data on the selected objects. All the stars, with the exception of HR 1016 (Pilachowski 1977) and HR 5058 (Luck & Bond 1991), were analyzed by Zacs (1994) who conducted a detailed analysis of a larger number of barium stars but used data with much lower S/N than ours.…”

Section: Observational Datamentioning

confidence: 99%

“…Visual magnitudes and spectral types are from the SIMBAD database. The effective temperatures (T eff ), log g, metallicities and barium abundances are from Zacs (1994) for all stars with the exception of HR 1016 (Pilachowski 1977), HR 4932 (McWilliam 1990), and HR 5058 (Luck & Bond 1991). The colors (V − K) and (R − I) are from Hoffleit & Jaschek (1982) and Johnson (1966).…”

Section: Introductionmentioning

confidence: 99%

“…Most of the available analyses are based on data with lower S/N ratio (Pilachowski 1977;Smith 1984;Kovacs 1985;Luck & Bond 1991;Zacs 1994). Thus, abundance errors in these works could possibly be blurring the small scale of the suggested nucleosynthetic effects.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Abundance analysis of barium and mild barium stars

Smiljanić¹,

Mello²,

Silva³

2007

A&A

View full text Add to dashboard Cite

Aims. We compare and discuss abundances and trends in normal giants, mild barium, and barium stars, searching for differences and similarities between barium and mild barium stars that could help shed some light on the origin of these similar objects. Also, we search for nucleosynthetic effects possibly related to the s-process that were observed in the literature for elements like Cu in other types of s-process enriched stars. Methods. High signal to noise, high resolution spectra were obtained for a sample of normal, mild barium, and barium giants.Atmospheric parameters were determined from the Fe i and Fe ii lines. Abundances for Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, and Gd, were determined from equivalent widths and model atmospheres in a differential analysis, with the red giant Vir as the standard star. Results. The different levels of s-process overabundances of barium and mild barium stars were earlier suggested to be related to the stellar metallicity. Contrary to this suggestion, we found in this work no evidence of barium and mild barium having a different range in metallicity. However, comparing the ratio of abundances of heavy to light s-process elements, we found some evidence that they do not share the same neutron exposure parameter. The exact mechanism controlling this difference is still not clear. As a by-product of this analysis we identify two normal red giants misclassified as mild barium stars. The relevance of this finding is discussed. Concerning the suggested nucleosynthetic effects possibly related to the s-process, for elements like Cu, Mn, V and Sc, we found no evidence for an anomalous behavior in any of the s-process enriched stars analyzed here. However, further work is still needed since a clear [Cu/Fe] vs. [Ba/Fe] anticorrelation exists for other s-process enriched objects.

show abstract

“…This star was previously analyzed by Luck & Bond (1991). Our results are in good agreement with theirs.…”

Section: Hr 5058supporting

confidence: 92%

Section: Observational Datamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Abundance analysis of barium and mild barium stars

Smiljanić¹,

Mello²,

Silva³

2007

A&A

View full text Add to dashboard Cite

show abstract

“…The mass-transfer hypothesis for the origin of Barium and CH stars was not without difficulties, as pointed out in papers by Luck & Bond (1982), Dominy & Lambert (1983), Bond (1991). Although evidence had been found from IUE spectra for white-dwarf companions to one or two Barium stars (Böhm-Vitense 1980;Dominy & Lambert 1983;Böhm-Vitense et al 1984), in fact, these programs had met with very limited success.…”

Section: Precursors To the Barium Starsmentioning

confidence: 99%

The Role of Binaries in the Carbon Star Phenomenon

McClure

2000

Symp. - Int. Astron. Union

View full text Add to dashboard Cite

Abstract. This presentation reviews the role that binaries play in the production of Barium, CH, and S stars. New radial velocity observations confirming the binary nature of subgiant CH stars are also discussed. Evidence is presented that the early R-type carbon stars exhibit no binaries. It is suggested that they were once all binaries, but having small separations, a coalescing companion has caused them to mix near the helium core flash. IntroductionIn a review of the roles of the various carbon stars, Scalo (1976) pointed out that the classical carbon stars lie above the luminosity of the onset of helium shell flashing on the asymptotic giant branch (AGB), as shown by Crabtree et al. (1976). But he noted that most Barium stars are too faint to be identified with double-shell models. Along with CH stars, their population II equivalents, they did not fit into the AGB scenario for production of carbon stars, even though they exhibit many of the same abundance characteristics. It seemed that they must be associated with the helium core flash, but standard stellar models did not predict mixing of the core flash material. The Barium, CH, and S stars 2

show abstract

Transformations between the 2MASS, SDSS, and BVI photometric systems for late‐type giants

Yaz¹,

Bilir

Karaali

et al. 2010

Astron Nachr

View full text Add to dashboard Cite

We present colour transformations from Two Micron All Sky Survey (2MASS) photometric system to Johnson‐Cousins system and to Sloan Digital Sky Survey (SDSS) system for late‐type giants and vice versa. The giant star sample was formed using surface gravity constraints (2 < log g ≤ 3) to Cayrel de Strobel et al.'s (2001) spectroscopic catalogue. 2MASS, SDSS and Johnson‐Cousins photometric data was taken from Cutri et al. (2003), Ofek (2008), and van Leeuwen (2007), respectively. The final sample was refined applying the following steps: (1) the data were dereddened, (2) the sample stars selected are of the highest photometric quality. We give two‐colour dependent transformations as a function of metallicity as well as independent of metallicity. The transformations provide absolute magnitudes and distance determinations which can be used in space density evaluations at relatively short distances where some or all of the SDSS magnitudes of late‐type giants are saturated (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

Subgiant CH stars. II - Chemical compositions and the evolutionary connection with barium stars

Cited by 138 publications

References 0 publications

Abundance analysis of barium and mild barium stars

Abundance analysis of barium and mild barium stars

The Role of Binaries in the Carbon Star Phenomenon

Transformations between the 2MASS, SDSS, and BVI photometric systems for late‐type giants

Contact Info

Product

Resources

About