A barium-rich binary central star in Abell 70
  We have found the central star of Abell 70 (PN G038.1-25.4, hereafter A 70) to be a binary consisting of a G8 IV-V secondary and a hot white dwarf. The secondary shows enhanced Ba II and Sr II features, firmly classifying it as a barium star. The nebula is found to have Type-I chemical abundances with helium and nitrogen enrichment, which combined with future abundance studies of the central star, will establish A 70 as a unique laboratory for studying s-process AGB nucleosynthesis. 
Henri M. J. Boffin, B. Miszalski, D. J. Frew, A. Acker, J. K\"oppen,   A. F. J. Moffat, and Q. A. Parker
astro-ph.GA