A Search for $^{6}$Li in Stars with Planets

Abstract

Using very high-resolution (R$\sim$ 125,000) and high quality (S/N $\geq$ 350) spectra, we have searched for $^{6}$Li in stars hosting extra-solar planets. From detailed profile-fitting of the Li {\sc i} resonance line at 6707.7 Å, we find no significant amount of $^{6}$Li relative to the $^{7}$Li for any of 8 planet bearing stars ($^{6}$Li/$^{7}$Li $\leq$ 0.0 - 0.03) with a strong Li {\sc i} lines. In particular, we do not confirm the presence of $^{6}$Li with $^{6}$Li/$^{7}$Li = 0.13 reported by Israelian et al.(2001) for HD 82943, a star with two known planets. Several of the 8 stars plus HD 219542 A, the planet-less primary of a binary, have been identified in the literature as possible recipients of accreted terrestrial material. For all of the planet-hosting stars and an additional 5 planet-less stars, we find no $^{6}$Li.