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

TL;DR

This paper proposes that bright supernova precursors are caused by outbursts from massive stars in binary systems with compact objects, where accretion onto the compact object energizes the outbursts, explaining observed properties.

Contribution

It introduces a novel binary interaction model involving compact objects to explain supernova precursors and their energetic outbursts, addressing previous observational and theoretical challenges.

Findings

Outbursts with moderate energies can be powered by accretion onto compact objects.

The model explains the observed luminosities and energies of supernova precursors.

Implications for detecting compact object binaries with Gaia and gravitational waves.

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 $10^{48}$--$10^{49}\ {\rm erg}$ that are 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 $10^{40-42}\,\rm erg\,s^{-1}$ 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.