Reference : High-resolution spectropolarimetric observations of hot subdwarfs
Scientific congresses and symposiums : Paper published in a journal
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
High-resolution spectropolarimetric observations of hot subdwarfs
Petit, P. [ > > ]
Van Grootel, Valérie mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie]
Bagnulo, S. [> > > >]
Charpinet, S. [> > > >]
Wade, G. A. [> > > >]
Green, E. M. [> > > >]
Leaflet - Astronomical Society of the Pacific
Astronomical Society of the Pacific
San Francisco
Fifth meeting on hot B subdwarfs and related objects
du 25 au 29 juillet 2011
South Africa Astronomical Observatory
Afrique du Sud
[en] We report on high-resolution spectropolarimetric observations of the hot subdwarf stars HD 76431 and Feige 66, using the ESPaDOnS echelle spectropolarimeter at CFHT. We compute cross-correlation Stokes I and V line profiles to enhance the signal-to-noise ratio. We then average all available cross-correlation profiles of each star to further decrease the noise level. Although both targets were previously reported to host kilo-gauss magnetic fields, we do not derive any evidence of large-scale photospheric fields from our sets of observations, in spite of tight error bars on the longitudinal field of the order of 60 gauss for HD 76431 and 200 gauss for Feige 66. A new analysis of FORS1 observations of HD 76431, which provided the basis for the original claim of field detection, confirms the absence of any detectable Zeeman signature, with an error bar of about 100 gauss on the longitudinal magnetic field.
Proceedings of the fifth meeting on hot subdwarf stars and related objects

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