Hydrogen-Rich to Stripped-Envelope:Observational Continuity and Biases in CCSNe

TL;DR

This paper reviews the continuum of core-collapse supernovae, emphasizing overlapping features and biases in classification, and advocates for viewing CCSNe as a multidimensional spectrum influenced by various physical processes.

Contribution

It introduces the concept of CCSNe as a multidimensional continuum, challenging traditional discrete subclass boundaries and highlighting the need for large datasets and advanced models.

Findings

Evidence of overlaps between supernova subclasses.

Physical processes create graded explosion outcomes.

Observational biases affect supernova classification.

Abstract

Although historically classified into discrete subclasses, there is growing evidence that indicates that core-collapse supernovae (CCSNe) categories often overlap, reflecting continuous variations in progenitor structure, mass-loss history, and circumstellar environments rather than strictly distinct channels. In this review, we explore the proposed continua that link hydrogen-rich Type II SNe to stripped-envelope explosions (IIb-Ib-Ic), and that extend further into interaction-dominated and superluminous events. We discuss the physical processes-stellar winds, binary interaction, eruptive outbursts, and circumstellar interaction-that may produce graded outcomes across classes, while highlighting where observational evidence supports or challenges smooth transitions. We propose that CCSNe are better viewed as a multidimensional continuum of explosion outcomes, where traditional subclasses act as reference points rather than strict boundaries. Future progress will rely on large, homogeneous datasets and advanced modeling to disentangle true evolutionary sequences from apparent overlaps, ultimately connecting progenitor pathways to the observed diversity of explosions