Bright Supernova Precursors by Outbursts from Massive Stars with Compact Object Companions

Abstract A fraction of core-collapse supernovae (SNe) with signs of interaction with a dense circumstellar matter are preceded by bright precursor emission. While the precursors are likely caused by a mass ejection before core collapse, their mechanism to power energetic bursts—sometimes reaching 10 48 –10 49 erg, which is larger than the binding energies of red supergiant envelopes—is still under debate. Remarkably, such a huge energy deposition should result in an almost complete envelope ejection and hence a strong sign of interaction, but the observed SNe with precursors show in fact typical properties among the interacting SNe. More generally, the observed luminosity of 10 40 −10 42 erg s −1 is shown to be challenging for a single SN progenitor. To resolve these tensions, we propose a scenario where the progenitor is in a binary system with a compact object (CO) and an outburst from the star leads to a super-Eddington accretion onto the CO. We show that for sufficiently short separations outbursts with moderate initial kinetic energies of 10 46 –10 47 erg can be energized by the accreting CO so that their radiative output can be consistent with the observed precursors. We discuss the implications of our model in relation to CO binaries detectable with Gaia and gravitational-wave detectors.