2009A&A...504.1011L

We report the detection of an unusually high lithium content in HD 232862, a field giant classified as a G8II star, and hosting a magnetic field. With the spectropolarimeters ESPaDOnS at CFHT and NARVAL at TBL, we collected high resolution and high signal-to-noise spectra of three giants: HD 232862, KU Peg and HD 21018. From spectral synthesis we inferred stellar parameters and measured lithium abundances that we compared to predictions from evolutionary models. We also analysed Stokes V signatures, looking for a magnetic field on these giants. HD 232862, presents a very high abundance of lithium (A_Li=2.45±0.25dex), far in excess of the theoretically value expected at this spectral type and for this luminosity class (i.e., G8II). The evolutionary stage of HD 232862 was determined, and it suggests a mass in the lower part of the [1.0M_☉, 3.5M_☉] mass interval, likely 1.5-2.0M_☉, at the bottom of the red giant branch. Also, a time variable Stokes V signature was detected in the data of HD 232862 and KU Peg, pointing to the presence of a magnetic field at the surface of these two rapidly rotating active stars.