Sufficiency of Massive Red-Supergiant Formation in High-sSFR Environments

Determine whether the number of massive red supergiants formed in high-specific-star-formation-rate environments is sufficient to raise the median luminosity of the red-supergiant population.

Background

The study finds that both median and upper-percentile red-supergiant luminosities increase with host specific star-formation rate. One possible explanation is that high-specific-star-formation-rate galaxies produce more massive stars, allowing the catalog to sample short-lived, highly luminous evolutionary phases near the Humphreys–Davidson limit.

However, the observed trend could also involve variability, binary mass transfer, stellar mergers, or modeling and selection effects. The paper explicitly leaves unresolved whether enhanced massive-star formation alone can account for the shift in the median population luminosity.

References

While these hypotheses may explain the high luminosity end of the sSFR-$\log(L/L_{\odot})$ relation (Figure \ref{fig:rsg_sfr_dependence}), it is unclear whether the number of massive RSGs formed in high sSFR environments is sufficient to increase median population luminosities.

— Extragalactic Multi-Band Exploration of Red Supergiants (EMBERS): Pipeline, Source Classification, and Bolometric Properties of 101,219 Red Supergiants from James Webb Space Telescope Imaging  (2609.19344 - Suresh et al., 16 Sep 2026) in Section 6.2, “Luminosity Function of RSGs and its Host Dependence”