Based on observations obtained at the Canada--France--Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France and the University of Hawaii.
Discovery of the first τ Sco analogues: HD 66665 and HD 63425★
Article first published online: 18 JAN 2011
© 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS
Monthly Notices of the Royal Astronomical Society: Letters
Volume 412, Issue 1, pages L45–L49, March 2011
How to Cite
Petit, V., Massa, D. L., Marcolino, W. L. F., Wade, G. A., Ignace, R. and The MiMeS Collaboration (2011), Discovery of the first τ Sco analogues: HD 66665 and HD 63425. Monthly Notices of the Royal Astronomical Society: Letters, 412: L45–L49. doi: 10.1111/j.1745-3933.2010.01002.x
- Issue published online: 11 MAR 2011
- Article first published online: 18 JAN 2011
- Accepted 2010 December 17. Received 2010 December 16; in original form 2010 October 30
- stars: early-type;
- stars: magnetic field
The B0.2 V magnetic star τ Sco stands out from the larger population of massive OB stars due to its high X-ray activity, peculiar wind diagnostics and highly complex magnetic field. This Letter presents the discovery of the first two τ Sco analogues – HD 66665 and HD 63425, identified by the striking similarity of their ultraviolet (UV) spectra to that of τ Sco. ESPaDOnS spectropolarimetric observations were secured by the Magnetism in Massive Stars CFHT Large Program, in order to characterize the stellar and magnetic properties of these stars. cmfgen modelling of optical ESPaDOnS spectra and archived IUE UV spectra showed that these stars have stellar parameters similar to those of τ Sco. A magnetic field of similar surface strength is found on both stars, reinforcing the connection between the presence of a magnetic field and wind peculiarities. However, additional phase-resolved observations will be required in order to assess the potential complexity of the magnetic fields and verify if the wind anomalies are linked to this property.