Lithium production in the merging of white dwarf stars (R. Longland et al.)

Vol. 542
In section 7. Stellar structure and evolution

Lithium production in the merging of white dwarf stars

by R. Longland, P. Lorén-Aguilar, J. José, E. García-Berro, L. G. Althaus, A&A 542, A117

R Coronae Borealis stars are hydrogen-poor giant stars. Two scenarios for their origin are being discussed: a late final He-shell flash after the star left the asymptotic giant branch, and the merging of two white dwarfs, one of which has a He core. The detection of Li in some R CrB stars was used as a strong argument for the final-flash scenario. This article presents nycleosynthesis calculations of a merger event. The authors conclude that it is possible to produce the observed Li abundances, which means that the detection of Li does not rule out a merger origin.