Pre-supernova outbursts of massive stars in the presence of a neutron star companion

We study the pre-explosion outbursts (PEOs) of massive stars that might result from a rapid expansion of the massive star in the presence of a close companion. We assume that activity in the core of the massive star, an initial mass of 15 M, about 2 yr before explosion energizes the envelope, and with the stellar evolutionary code MESA follow the inflated envelope as a result of energy deposition to the envelope. We examine the conditions for a companion star to accrete mass from the inflated envelope. We find that for the general conditions that we assume, bright PEOs require a neutron star companion at an orbital separation of ≈1000-2000 R. We assume that the mass-accreting neutron star launches jets. These jets shape the circumstellar matter to highly non-spherical structures, such that the explosions of core collapse supernovae that follow PEOs might lack an axial (cylindrical) symmetry. In some case main-sequence star companions can also energize PEOs, but much weaker ones. This study adds another scenario by which neutron stars can power the radiation of PEOs. Another scenario is the common envelope jets supernova impostor where a neutron star enters the envelope of the massive star.