Sophie Abrahams (York/Los Alamos)

In a binary system, the envelope of the primary can expand - for example as the star enters its red giant phase - and overflow its Roche Lobe. The envelope material accretes onto the secondary star and, if the material moves onto the star faster than it can be accreted, the secondary star can be engulfed entirely by the envelope of the primary - forming a common envelope. If the secondary star is a neutron star, there is an opportunity for nucleosynthesis to occur in the accretion disk formed around the neutron star. When the material is ejected from the accretion disk, some of it is able to move back into the companion - significant since in most neutron star accretion scenarios the material cannot escape the gravity of the neutron star - and this material could be ejected into the interstellar medium when the primary goes through its supernova. As such, understanding the nucleosynthesis of this system is of great interest. Keegans et al. 2019 explored this nucleosynthesis for the first time with simplistic trajectories, and found that this scenario could be important to galactic chemical evolution. The work presented is developed from Keegans et al. 2019, using more detailed trajectories which take into account that angular momentum is required to form an accretion disk. Within the trajectories, variables such as accretion rate, and how far into the accretion disk the material moves prior to ejection are explored. In this talk, ongoing research exploring nucleosynthesis in accreting neutron star common envelopes is presented.