Strong Ultraviolet Pulse From a Newborn Type Ia Supernova

TL;DR

This paper reports early ultraviolet observations of a Type Ia supernova, providing evidence that supports the single degenerate progenitor model involving a white dwarf and a companion star.

Contribution

First direct evidence linking ultraviolet emission to the collision with a companion star in a Type Ia supernova, supporting the single degenerate progenitor scenario.

Findings

Ultraviolet emission observed within four days of explosion.

Emission consistent with collision between supernova ejecta and companion star.

Supports the single degenerate progenitor model for some Type Ia supernovae.

Abstract

Type Ia supernovae are destructive explosions of carbon oxygen white dwarfs. Although they are used empirically to measure cosmological distances, the nature of their progenitors remains mysterious, One of the leading progenitor models, called the single degenerate channel, hypothesizes that a white dwarf accretes matter from a companion star and the resulting increase in its central pressure and temperature ignites thermonuclear explosion. Here we report observations of strong but declining ultraviolet emission from a Type Ia supernova within four days of its explosion. This emission is consistent with theoretical expectations of collision between material ejected by the supernova and a companion star, and therefore provides evidence that some Type Ia supernovae arise from the single degenerate channel.