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 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.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2021
- DOI:
- 10.1093/mnras/staa3768
- arXiv:
- arXiv:2010.07482
- Bibcode:
- 2021MNRAS.501.2677D
- Keywords:
-
- techniques: polarimetric;
- stars: early-type;
- stars: individual: NGC 1624-2;
- stars: magnetic field;
- stars: winds;
- outflows;
- ultraviolet: stars;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 12 pages, 3 figures, accepted for publication by MNRAS (2020 December 1)