Very low upper limits on the strength of interstellar lithium lines toward SN 1987 A

Seven CCD and eleven Reticon spectra of high spectral resolution and low noise have been carefully analysed in search for faint absorption lines due to neutral interstellar lithium lambda6708 Å along the line of sight to SN 1987A in the Large Magellanic Cloud. At the velocities of the strongest interstellar Ca II and Na I lines, no evidence of any interstellar feature has been found. An upper limit for the strongest components expected is 0.15 mÅ for both the Galaxy and the LMC. From these the authors infer elemental column densities N[SUB]Galaxy[/SUB] <= 2.6×10[SUP]11[/SUP]cm[SUP]-2[/SUP] and N[SUB]LMC[/SUB] <= 1.4×10[SUP]11[/SUP]cm[SUP]-2[/SUP] and gaseous elemental abundances (Li/H I)[SUB]Galaxy[/SUB] <= 7.7×10[SUP]-10[/SUP] and (Li/H I)[SUB]LMC[/SUB] <= 1.0×10[SUP]-10[/SUP] with an estimated uncertainty of the abundance limits of a factor of 4 (0.6 dex).