Elemental abundances of metal poor carbon rich lead star: CS29497-030
  We present here the abundance analysis of a metal poor carbon rich lead star, CS29497-030. High resolution and high signal to noise spectra were obtained using the UVES spectrograph on the 8.2m VLT-Kueyen telescope. The observations were made as a part of the Large Programme 165.N-0276, P.I. R. Cayrel. Abundance analysis was done using the latest version of the MARCS model atmospheres (Plez et. al. 1992) and the turbospectrum spectrum synthesis code. We have derived Teff = 6650K from the FeI lines. Visible and infrared broad band colours using the Alonso et al. (1996) calibration, gives similar temperatures. A log g value of 3.5 was obtained from the ionisation equilibrium of FeI and FeII, we remark that this gravity also satisfies the MgI/MgII, TiI/TiII and MnI/MnII equilibria, within errors. The abundance analysis indicates a metallicity, [Fe/H] = --2.7. A large overabundance of carbon ([C/Fe]=2.7) was found. We have also found large enhancement in the s-process elements and in particular lead shows an extremely high abundance of [Pb/Fe]=3.5, which makes this the star with the highest Pb/Fe ratio, up to date. The Pb/Ba ratio is found to be high ([Pb/Ba]=1.2) and the same s true for other second-peak s-process elements(e.g La, Ce, Nd). The star is a known spectroscopic binary with a period of 346 days (Preston & Sneden 2000). The abundance pattern suggests that CS 29497-30 has accreted matter from its companion, when it was in the AGB phase. 
T. Sivarani, P. Bonifacio, P. Molaro, R. Cayrel, M. Spite, F. Spite,   B.Plez, J. Andersen, B. Barbuy, T.C. Beers, E. Depagn...