TYC 8327-1678-1: a new super lithium-rich K giant

Abstract

ABSTRACTIn this work, we show that TYC 8327-1678-1 is a low-mass red giant star with a super lithium abundance in its atmosphere. For this, we used high-resolution spectroscopy to determine atmospheric parameters, the chemical abundances of the light elements and the isotopic ratio 12C/13C using the spectral synthesis techniques and the equivalent width measurements. Also, we used theoretical evolutionary tracks to find out the mass and the evolutionary stage of TYC 8327-1678-1. The lithium abundance was determined using the Li i resonance doublet at  6708 Å  and the subordinate line at  6104 Å that yielding a mean value of $\log \, \epsilon {\rm (Li)_{NLTE}}\, =\, 3.48$. The projected rotational velocity ($v\, \sin \, i$) has been determined using spectral synthesis based on the isolated Fe i lines. Our results show that TYC 8327-1678-1 has a mass of $M\, =\, 1.60$ $\pm \, 0.20\, {\rm M}_{\odot }$, a low rotational velocity ($v\, \sin \, i$ = 2.35 ± 0.24 km s−1) and metallicity of [Fe/H] = +0.23 ± 0.09. Finally, we discuss the possibility that TYC 8327-1678-1 became a lithium-rich star after a merging event involving a red giant and a helium white dwarf.