HD 77361: a new case of super li-rich K giant with anomalous low 12C/13C ratio.
KUMAR Y.B. and REDDY B.E.
Abstract (from CDS):
Result. from high-resolution spectroscopic analysis of HD 77361 are reported. LTE analysis shows that HD 77361 is a K giant of atmospheric parameters: Teff= 4580±75 K, log g = 2.5±0.1, and ξt= 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 to 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 red giant branch (RGB) luminosity bump phase, HD 77361 shows a 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☉= 1.66±0.1) low-mass K giant (M = 1.5±0.2 M☉) among the known super Li-rich K giants that has a very low 12C/13C ratio. Result. of HD 77361 further constrain our theoretical understanding of Li enhancement in the atmospheres of RGB stars.