Coordinated Research Action 2008 - 2013 (ARC)

Heavy elements in the universe:

stellar evolution, nucleosynthesis and abundance determinations


The traditional research niche of the Institut d'Astronomie et d'Astrophysique (IAA) is to relate the stellar surface composition studied through high-resolution stellar spectroscopy and dedicated model atmospheres to the internal nucleosynthesis and mixing processes studied so far with the help of 1-D stellar evolution codes. The central question for this project is: How do the various processes building up heavy elements really operate and in which types of stars? The nucleosynthesis processes can be divided in two classes. Nuclei lighter than 56Fe are basically produced through the nuclear reactions responsible for the stellar energy generation. Elements heavier than iron cannot be synthesized by fusion reactions, as those are endothermic. Instead, processes involving successive neutron- or proton-captures must be invoked: the slow and rapid neutron capture processes (s- and r-processes respectively) form nuclides along the neutron-rich side of the valley of nuclear stability, whereas the proton-process or simply p-process, is responsible for the production of proton-rich nuclides. How exactly these three processes actually operate in stars still eludes us.
This project will investigate the following astrophysical sites of heavy-element nucleosynthesis:

  • r-process and spallation
  • s-process
  • p-process

The role of binaries in the formation of stars enriched with heavy elements will be investigated, through the development and exploitation of the new code BINSTAR, daughter of STAREVOL, which follows simultaneously the evolution of the two components of a binary system, through the consideration of stellar structure, internal mixing, spin-orbit coupling, mass exchanges, spin accretion...


A. Jorissen (P.I.)
N. Chamel (co-I)
S. Goriely (co-I)
L. Siess (co-I)
S. Van Eck (co-I)

Behara N. (post-doc, November 2009 - September 2011)
Chiavassa A. (post-doc, October 2010 - ..)
Daoutidis J. (post-doc, February 2010 - ..)
Deschamps R. (PhD, October 2010 - ..)
Fantina A. (post-doc, November 2010 - ..)
Neyskens P. (PhD, October 2009 - ..)
Masseron T. (post-doc, September 2009 - ..)
Mocak M. (post-doc, February 2009 - November 2010)
Xu Yi (post-doc, May 2009 - ..)

Internal documentation (Internal use only)