Explosions of pulsating red supergiants: a natural pathway for the diversity of Type II-P/L supernovae

Red supergiants (RSGs), which are progenitors of hydrogen-rich Type II supernovae (SNe), have been known to pulsate, both from observations and theory. The pulsations can be present at core collapse and affect the resulting SN. However, SN light curve models of such RSGs commonly use hydrostatic pro...

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Bibliographic Details
Main Authors: Bronner, Vincent A. (Author) , Laplace, Eva (Author) , Schneider, Fabian (Author) , Podsiadlowski, Philipp (Author)
Format: Article (Journal)
Language:English
Published: November 2025
In: Astronomy and astrophysics
Year: 2025, Volume: 703, Pages: 1-21
ISSN:1432-0746
DOI:10.1051/0004-6361/202554642
Online Access:Verlag, kostenfrei, Volltext: https://doi.org/10.1051/0004-6361/202554642
Verlag, kostenfrei, Volltext: https://www.aanda.org/articles/aa/abs/2025/11/aa54642-25/aa54642-25.html
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Author Notes:V.A. Bronner, E. Laplace, F.R.N. Schneider, and Ph. Podsiadlowski
Description
Summary:Red supergiants (RSGs), which are progenitors of hydrogen-rich Type II supernovae (SNe), have been known to pulsate, both from observations and theory. The pulsations can be present at core collapse and affect the resulting SN. However, SN light curve models of such RSGs commonly use hydrostatic progenitor models and ignore pulsations. Here, we model the final stages of a 15 M<sub>⊙<sub/> RSG and self-consistently follow the hydrodynamical evolution. We observe the growth of large-amplitude radial pulsations in the envelope. After a transient phase in which the envelope restructures, the pulsations settle to a steady and periodic oscillation with a period of 817 days. We show that they are driven by the <i>κγ<i/> mechanism, which is an interplay between changing opacities and the release of recombination energy of hydrogen and helium. This leads to complex and incoherent expansion and contraction in different parts of the envelope, which greatly affects the SN progenitor properties, including its location in the Hertzsprung-Russell diagram. We simulate SN explosions of this model at different pulsation phases. Explosions in the compressed state result in a flat light curve (Type II-P). In contrast, the SN light curve in the expanded state declines rapidly, reminiscent of a Type II-L SN. For cases in between, we find light curves with various decline rates. Features in the SN light curves are directly connected to features in the density profiles. These are, in turn, linked to the envelope ionization structure, which is the driving mechanism of the pulsations. We predict that some of the observed diversity in Type II SN light curves can be explained by RSG pulsations. For more massive RSGs, we expect stronger pulsations that might even lead to dynamical mass ejections of the envelope and to an increased diversity in SN light curves.
Item Description:Online verfügbar: 06. November 2025
Gesehen am 06.03.2026
Physical Description:Online Resource
ISSN:1432-0746
DOI:10.1051/0004-6361/202554642