First evidence of a magnetic field on Vega Towards a new class of magnetic A-type stars ⋆

@article{Lignires2009FirstEO,
  title={First evidence of a magnetic field on Vega Towards a new class of magnetic A-type stars ⋆},
  author={François Ligni{\`e}res and Pascal Petit and Torsten Bohm and Michel Auri{\`e}re},
  journal={Astronomy and Astrophysics},
  year={2009},
  volume={500}
}
Aims. We report the detection of a magnetic field on Vega through spe ctropolarimetric observations. Methods. We acquired 257 Stokes V, high signal-to-noise and high-resolution echelle spectra during four consecutive nights wit h the NARVAL spectropolarimeter at the 2-m Telescope Bernard Lyot of Observatoire du Pic du Midi (France). A circularly polarized signal in line profiles is unambiguously detected after comb ining the contribution of about 1200 spectral lines for each spectrum and… 

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References

SHOWING 1-10 OF 30 REFERENCES
Weak magnetic fields in Ap/Bp stars - Evidence for a dipole field lower limit and a tentative interp
Aims. We investigated a sample of 28 well-known spectroscopically-identified magnetic Ap/Bp stars, with weak, poorly-determined or previously undetected magnetic fields. The aim of this study is to
A highly sensitive search for magnetic fields in B, A and F stars
Circular spectropolarimetric observations of 74 stars were obtained in an attempt to detect magnetic fields via the longitudinal Zeeman eect in their spectral lines. The sample observed includes 22
Magnetic field measurements and wind-line variability of OB-type stars
Context. The first magnetic fields in O- and B-type stars that do not belong to the Bp-star class, have been discovered. The cyclic UV wind-line variability, which has been observed in a significant
Spectropolarimetric observations of active stars
This paper reports the results of five years (five runs, 23 nights) of spectropolarimetric observations of active stars with the UCL Echelle Spectrograph of the Anglo-Australian Telescope. 225
The weak magnetic field of the O9.7 supergiant ζ Orionis A
We report here the detection of a weak magnetic field of 50-100 G on the O9.7 supergiant ζ Orionis A (ζ Ori A), using spectropolarimetric observations obtained with NARVAL at the 2-m TBernard Lyot
Searching for Links Between Magnetic Field and Stellar Evolution: a Survey of Magnetic Stars in Open Clusters with FORS1 at the VLT
Context. A small fraction of upper main sequence stars have strong, highly structured magnetic fields. The origin and evolution of these fields are not adequately understood. Aims. We are carrying
A search for magnetic fields in the variable HgMn star α andromedae
Context: .The chemically peculiar HgMn stars are a class of Bp stars which have historically been found to be both non-magnetic and non-variable. Remarkably, it has recently been demonstrated that
Magnetism of Herbig Ae/Be stars
Observations of magnetic fields of stars at the pre-main sequence phase can provide important new insights into the complex physics of the late stages of star formation. This is especially true at
First Results from the CHARA Array. VII. Long-Baseline Interferometric Measurements of Vega Consistent with a Pole-On, Rapidly Rotating Star
We have obtained high-precision interferometric measurements of Vega with the CHARA Array and FLUOR beam combiner in the K’ band at projected baselines between 103m and 273m. The measured visibility
Searching for links between magnetic fields and stellar evolution - I. A survey of magnetic fields in open cluster A- and B-type stars with FORS1
Context. About 5% of upper main sequence stars are permeated by a strong magnetic field, the origin of which is still matter of debate. Aims. With this work we provide observational material to study
...
1
2
3
...