New observations of NGC 1624-2 reveal a complex magnetospheric structure and underlying surface magnetic geometry

Abstract

NGC 1624-2 is the most strongly magnetized O-type star known. Previous spectroscopic observations of this object in the ultraviolet provided evidence that it hosts a large and dense circumstellar magnetosphere. Follow-up observations obtained with the \textit{Hubble Space Telescope} not only confirm that previous inference, but also suggest that NGC 1624-2's magnetosphere has a complex structure. Furthermore, an expanded spectropolarimetric time series shows a potential departure from a dipolar magnetic field geometry, which could mean that the strongest field detected at the surface of an O-type star is also topologically complex. This result raises important questions regarding the origin and evolution of magnetic fields in massive stars.

12 pages, 3 figures, accepted for publication by MNRAS (2020 December 1)

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Cited by in corpus (10)

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• The effects of surface fossil magnetic fields on massive star evolution: III. The case of $\tau$ Sco
• Magnetism in High-Mass Stars
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• Magnetically confined wind shock
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