A magnetic massive star has experienced a stellar merger

• 成果类型: Article
• 署名作者: Frost, A. J.; Sana, H.; Mahy, L.; Wade, G.; Barron, J.; Le Bouquin, J. -b.; Merand, A.; Schneider, F. R. N.; Shenar, T.; Barba, R. H.; Bowman, D. M.; Fabry, M.; Farhang, A.; Marchant, P.; Morrell, N. I.; Smoker, J. V.
• 署名单位: KU Leuven; European Southern Observatory; Royal Military College - Canada; Queens University - Canada; Centre National de la Recherche Scientifique (CNRS); Institut de Planetologie et d'Astrophysique de Grenoble (IPAG); Communaute Universite Grenoble Alpes; Universite Grenoble Alpes (UGA); Ruprecht Karls University Heidelberg; Tel Aviv University; Universidad de La Serena; Newcastle University - UK; Institute for Research in Fundamental Sciences IPM; Carnegie Institution for Science; University of Edinburgh
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10794
• DOI: 10.1126/science.adg7700
• 发表日期: 2024-04-12
• 页码: 214-217
• 关键词: dynamical simulations; mimes survey; field; EVOLUTION; nebula; hd-148937; origin; winds

摘要

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.