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A Stripped Giant Left Three Oxygen Peaks

Late spectra of the very metal-poor supernova 2023ufx point to an asymmetric explosion, a 25-to-35-solar-mass progenitor and complex earlier mass loss.

Published Updated Story ID: mp-2026-09-07-014
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Summary

Late spectra of the very metal-poor supernova 2023ufx point to an asymmetric explosion, a 25-to-35-solar-mass progenitor and complex earlier mass loss.

A nebular spectrum taken about a year after explosion shows a triple-peaked oxygen line. Comparisons with models favor a zero-age main-sequence mass of roughly 25 to 35 Suns, while the low calcium-to-oxygen ratio supports a massive progenitor. Broad, boxy hydrogen emission and a flattening late light curve suggest material lost centuries to millennia before the blast. The authors conclude the event came from a heavily stripped red supergiant in a 2-to-7-percent-solar-metallicity environment; those inferences remain model-dependent.

Why it matters

Late spectra of the very metal-poor supernova 2023ufx point to an asymmetric explosion, a 25-to-35-solar-mass progenitor and complex earlier mass loss.

Limits and context

  • The authors conclude the event came from a heavily stripped red supergiant in a 2-to-7-percent-solar-metallicity environment; those inferences remain model-dependent.

Key claims

  1. Late spectra of the very metal-poor supernova 2023ufx point to an asymmetric explosion, a 25-to-35-solar-mass progenitor and complex earlier mass loss.

    Qualification: The authors conclude the event came from a heavily stripped red supergiant in a 2-to-7-percent-solar-metallicity environment; those inferences remain model-dependent.

    Evidence: source-2026-09-07-014

Sources

  1. arXiv preprint 2609.04307arXiv · primary research

Corrections

No corrections have been recorded for this story.