Three Li-rich K Giants: IRAS 12327-6523, 13539-4153, and 17596-3952

Abstract

We report on spectroscopic analyses of three K giants previously suggested to be Li-rich: IRAS 12327-6523, 13539-4153, and 17596-3952. High-resolution optical spectra and the LTE model atmospheres are used to derive the stellar parameters (Teff, log g, [Fe/H]), elemental abundances, and the isotopic ratio 12C/13C. IRAS 13539-4153 shows an extremely high Li abundance of log epsilon(Li) approx 4.2, a value 10 times greater than the present Li abundance in the local interstellar medium. This is the third highest Li abundance yet reported for a K giant. IRAS 12327-6523 shows a Li abundance of log epsilon(Li) approx 1.4. IRAS 17596-3952 is a rapidly rotating (V sin i approx 35 km s-1) K giant with log epsilon(Li) approx 2.2. Infrared photometry shows the presence of an IR excess, suggesting mass loss. A comparison is made between these three stars and previously recognized Li-rich giants.