Boil-off of red supergiants: mass loss and type II-P supernovae

Abstract

The mass loss mechanism of red supergiant stars is not well understood, even though it has crucial consequences for their stellar evolution and the appearance of supernovae that occur upon core-collapse. We argue that outgoing shock waves launched near the photosphere can support a dense chromosphere between the star's surface and the dust formation radius at several stellar radii. We derive analytic expressions for the time-averaged density profile of the chromosphere, and we use these to estimate mass loss rates due to winds launched by radiation pressure at the dust formation radius. These mass loss rates are similar to recent observations, possibly explaining the upward kink in mass loss rates of luminous red supergiants. Our models predict that low-mass red supergiants lose less mass than commonly assumed, while high-mass red supergiants lose more. The chromospheric mass of our models is $\sim$0.01 solar masses, most of which lies within a few stellar radii. This can help explain the early light curves and spectra of type-II P supernovae without requiring extreme pre-supernova mass loss. We discuss implications for stellar evolution, type II-P supernovae, SN 2023ixf, and Betelgeuse.

Accepted to the Open Journal of Astrophysics

Cited by in corpus (12)

• No rungs attached: A distance-ladder free determination of the Hubble constant through type II supernova spectral modelling
• The effect of mass loss in models of red supergiants in the Small Magellanic Cloud
• Red Supergiant Mass Loss and Mass-Loss Rates
• SN 2023ixf -- an average-energy explosion with circumstellar medium and a precursor
• The landscape of binary core-collapse supernova progenitors and the late emergence of Wolf-Rayet winds
• Inferring CSM Properties of Type II SNe Using a Magnitude-Limited ZTF Sample
• One Year of SN 2023ixf: Breaking Through the Degenerate Parameter Space in Light-Curve Models with Pulsating Progenitors
• SN 2024ggi: another year, another striking Type II supernova
• Investigating the metallicity dependence of the mass-loss rate relation of red supergiants
• Spectropolarimetric modeling of interacting Type II supernovae. Application to early-time observations of SN1998S
• Explosions of pulsating red supergiants: a natural pathway for the diversity of Type II-P/L supernovae
• XSNAP: An X-ray Supernova Analysis Pipeline with Application to the Type II Supernova 2024ggi