A magnetic massive star has experienced a stellar merger

A. J. Frost*, H. Sana, L. Mahy, G. Wade, J. Barron, J. B. Le Bouquin, A. Mérand, F. R.N. Schneider, T. Shenar, R. H. Barbá, D. M. Bowman, M. Fabry, A. Farhang, P. Marchant, N. I. Morrell, J. V. Smoker

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Massive stars (those ≥8 solar masses at formation) have radiative envelopes that cannot sustain a dynamo, the mechanism that produces magnetic fields in lower-mass stars. Despite this, approximately 7% of massive stars have observed magnetic fields, the origin of which is debated. We used multi-epoch interferometric and spectroscopic observations to characterize HD 148937, a binary system of two massive stars. We found that only one star is magnetic and that it appears younger than its companion. The system properties and a surrounding bipolar nebula can be reproduced with a model in which two stars merged (in a previous triple system) to produce the magnetic massive star. Our results provide observational evidence that magnetic fields form in at least some massive stars through stellar mergers.

Original languageEnglish
Pages (from-to)214-217
Number of pages4
Issue number6692
StatePublished - 12 Apr 2024


FundersFunder number
Engineering and Physical Sciences Research Council
ERC Horizon Europe funding guarantee
UK Research and Innovation
Horizon 2020 Framework Programme772225, 945806
Horizon 2020 Framework Programme
Deutsche ForschungsgemeinschaftEXC 2181/1-390900948
Deutsche Forschungsgemeinschaft
Fonds Wetenschappelijk Onderzoek1286521N
Fonds Wetenschappelijk Onderzoek
Royal SocietyURF\R1\231631
Royal Society


    Dive into the research topics of 'A magnetic massive star has experienced a stellar merger'. Together they form a unique fingerprint.

    Cite this