# Dust Formation and the Binary Companions of Supernovae

## TL;DR

This paper explores how binary companions influence dust formation in supernovae, suggesting that luminous companions can suppress dust creation and that this interaction explains observed variations in dust content across different supernovae types.

## Contribution

It introduces a model linking binary companion properties to dust formation outcomes, reconciling conflicting observations in supernova dust production.

## Key findings

- Luminous companions can suppress dust formation by photo-ionization.
- Supernovae without luminous companions tend to form more dust.
- The presence of a binary companion explains variability in dust observed in supernova remnants.

## Abstract

Supernovae (SNe) should both frequently have a binary companion at death and form significant amounts of dust. This implies that any binary companion must lie at the center of an expanding dust cloud and the variable obscuration of the companion as the SN remnant (SNR) expands will both unambiguously mark the companion and allow the measurement of the dust content through absorption rather than emission for decades after the explosion. However, sufficiently hot and luminous companions can suppress dust formation by rapidly photo-ionizing the condensible species in the ejecta. This provides a means of reconciling the Type IIb SNe Cas A, which lacks a luminous companion and formed a significant amount of dust (Md > 0.1 Msun), with the Type IIb SNe 1993J and 2011dh, both of which appear to have a luminous companion and to have formed a negligible amount of dust (Md < 0.001 Msun). The Crab and SN 1987A are consistent with this picture, as both lack a luminous companion and formed significant amounts of dust. An unrecognized dependence of dust formation on the properties of binary companions may help to explain why the evidence for dust formation in SNe appears so contradictory.