# The strongly interacting binary scenarios of the enigmatic supernova iPTF14hls

## TL;DR

This paper explores how strong binary interactions are essential in various proposed models for the unusual supernova iPTF14hls, highlighting their rarity and potential to explain other rare supernovae types.

## Contribution

It demonstrates that all plausible scenarios for iPTF14hls involve a binary companion, emphasizing the importance of binary interactions in explaining this supernova's peculiar features.

## Key findings

- Binary companions are crucial in all proposed models for iPTF14hls.
- Strong binary interactions are rare but may explain the supernova's enigmatic nature.
- Binary interactions could be key in other rare supernova phenomena.

## Abstract

We argue that some scenarios for the enigmatic supernova (SN) iPTF14hls and its progenitor require a strong binary interaction. We examine scenarios that attribute the extra power of iPTF14hls to a magnetar, to a late fallback on to the neutron star (NS) that launches jets, to an interaction of the ejecta with a circumstellar matter (CSM), or to a common envelope jets SN (CEJSN). For each of these four scenarios, we study the crucial process that supplies the extra energy and conclude that a binary companion to the progenitor must be present. For the magnetar scenario and late jets we claim that a companion should spin-up the pre-collapse core, in the ejecta-CSM scenario we find that the formation of the equatorial CSM requires a companion, and in the CEJSN where a NS spirals-in inside the giant envelope of the progenitor and launches jets the strong binary interaction is built-in. We argue that these types of strong binary interactions make the scenarios rare and explain the enigmatic nature of iPTF14hls. We further study processes that might accompany the binary interaction, in particular, the launching of jets before, during and after the explosion and their observational consequences. We do not consider the difficulties of the different scenarios and neither do we determine the best scenario for iPTF14hls. We rather focus on the binary nature of these scenarios that might as well explain other rare types of SNe.