ABUNDANCE SIMILARITIES BETWEEN THE R-CRB STAR V854 CEN AND THE BORN-AGAIN SAKURAIS OBJECT

The elemental abundances of the mildly hydrogen-deficient R Coronae Bo realis (R CrB) star V854 Cen have been estimated. The R CrB stars have been divided into majority and minority classes judging by their abun dance patterns. Class assignment has previously been unambiguous but V 854 Cen has traits of both the minority and majority class. Neither V8 54 Cen nor the three obvious minority members show any clear abundance signatures of having been affected by e.g. dust-gas separation as oft en observed in post-AGE stars. By chemical composition, V854 Cen close ly resembles Sakurai's object, which has probably recently experienced a final He-shell flash. Therefore V854 Cen and Sakurai's object may s hare the same evolutionary background, which would add support for the final-flash scenario as a viable origin of the R CrB stars. Most of t he few differences in abundance ratios between the stars could if so b e attributed to milder H-ingestion in connection with the final He-she ll flash of V854 Cen. The identification of either the majority or the minority group, if any, as final flash objects, remain uncertain, how ever, due to the unclear membership status of V854 Cen.