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arXiv · 0908.2685

HD 77361: A new case of super Li-rich K giant with anomalous low 12C/13C ratio

Bharat Kumar Yerra·Bacham Eswar Reddy
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Abstract

Results from high resolution spectroscopic analysis of HD 77361 are reported. The LTE analysis shows that HD 77361 is a K giant of atmospheric parameters: Teff = 4580 +/- 75 K, log$g$ = 2.5 +/- 0.1, and ξ_{t} = 1.40 +/-0.5 km/s. We found that the atmosphere of HD 77361 is highly enriched in Li with log ε(Li) = 3.82 +/- 0.1. With this finding the total number of super Li-rich K giants (log ε(Li) >= 3.3 ISM value) known till date reached six. Contrary to first dredge-up, extra-deep mixing and the associated cool bottom processing, and other recent predictions for K giants on the RGB luminosity bump phase, HD 77361 shows very low value of 12C/13C = 4.3 +/- 0.5 having, simultaneously, very large amount of Li. Also, HD 77361 is the only population I low luminosity (log L/L_sun = 1.66 +/- 0.1) low mass K giant (M = 1.5 +/- 0.2M_sun) among the known super Li-rich K giants that has a very low 12C/13C ratio. Results of HD 77361 further constrain our theoretical understanding of Li enhancement in the atmospheres of RGB stars.

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Bharat Kumar Yerra, Bacham Eswar Reddy. 2009-08-19. HD 77361: A new case of super Li-rich K giant with anomalous low 12C/13C ratio. https://arxiv.org/abs/0908.2685

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