The Li abundances of the two components of the very metal-poor ( [ Fe/H ] = -2.5 ) double-lined spectroscopic binary G 166–45 ( BD+26 ^ { \circ } 2606 ) are determined separately based on high resolution spectra obtained with the Subaru Telescope High Dispersion Spectrograph and its image slicer .
From the photometric colors and the mass ratio the effective temperatures of the primary and secondary components are estimated to be 6350 \pm 100 K and 5830 \pm 170 K , respectively .
The Li abundance of the primary ( A ( Li ) = 2.23 ) agrees well with the Spite plateau value , while that of the secondary is slightly lower ( A ( Li ) = 2.11 ) .
Such a discrepancy of the Li abundances between the two components is previously found in the extremely metal-poor , double-lined spectroscopic binary CS 22876–032 , however , the discrepancy in G 166–45 is much smaller .
The results agree with the trends found for Li abundance as a function of effective temperature ( and of stellar mass ) of main-sequence stars with -3.0 < [ Fe/H ] < -2.0 , suggesting that the depletion of Li at T _ { eff } \sim 5800 K is not particularly large in this metallicity range .
The significant Li depletion found in CS 22876–032B is a phenomenon only found in the lowest metallicity range ( [ Fe/H ] < -3 ) .