Related papers: Are magnetic fields universal in O-type multiple s…
Magnetic fields are regarded as a crucial element for our understanding of stellar physics. They can be studied with a variety of methods which provide complementary - and sometimes contradictory - information about the structure, strength…
Massive star winds are important contributors to the energy, momentum and chemical enrichment of the interstellar medium. Strong, organized and predominantly dipolar magnetic fields have been firmly detected in a small subset of massive…
We present our first results on a new sample containing all single G,K and M giants down to V = 4 mag in the Solar vicinity, suitable for spectropolarimetric (Stokes V) observations with Narval at TBL, France. For detection and measurement…
In this paper, we describe an analysis of the MiMeS Survey of O-type stars to explore the range of dipolar field strengths permitted by the polarisation spectra that do not yield a magnetic detection. We directly model the Stokes V profiles…
Over the last decade, large-scale, organized (generally dipolar) magnetic fields with a strength between 0.1 and 20 kG were detected in dozens of OB stars. This contribution reviews the impact of such magnetic fields on the stellar winds of…
Although magnetic fields have been discovered in ten massive O-type stars during the last years, the origin of their magnetic fields remains unknown. Among the magnetic O-type stars, two stars, HD36879 and HD57682, were identified as…
Recent magnetic field surveys in O- and B-type stars revealed that about 10% of the core-hydrogen-burning massive stars host large-scale magnetic fields. The physical origin of these fields is highly debated. To identify and model the…
A significant fraction of massive main-sequence stars show strong, large-scale magnetic fields. The origin of these fields, their lifetimes, and their role in shaping the characteristics and evolution of massive stars are currently not well…
For several decades we have been cognizant of the presence of magnetic fields in early-type stars, but our understanding of their magnetic properties has recently (over the last decade) expanded due to the new generation of high-resolution…
Low-mass stars are known to have magnetic fields that are believed to be of dynamo origin. Two complementary techniques are principally used to characterise them. Zeeman-Doppler imaging (ZDI) can determine the geometry of the large-scale…
Magnetic fields are ubiquitous in the Universe. The Sun's magnetic field drives the solar wind and causes solar flares and other energetic surface phenomena that profoundly affect space weather here on Earth. The first magnetic field in a…
Close M-dwarf binaries and higher multiples allow the investigation of rotational evolution and mean magnetic flux unbiased from scatter in inclination angle and age since the orientation of the spin axis of the components is most likely…
The presence of magnetic fields at the surfaces of many massive stars has been suspected for decades, to explain the observed properties and activity of OB stars. However, very few genuine high-mass stars had been identified as magnetic…
We investigate how the observed large-scale surface magnetic fields of low-mass stars (~0.1 -- 2 Msun), reconstructed through Zeeman-Doppler imaging (ZDI), vary with age t, rotation and X-ray emission. Our sample consists of 104 magnetic…
One of the defining processes which govern massive star evolution is their continuous mass loss via dense, supersonic line-driven winds. In the case of those OB stars which also host a surface magnetic field, the interaction between that…
Although indirect evidence for the presence of magnetic fields in high-mass stars is regularly reported in the literature, the detection of these fields remains an extremely challenging observational problem. We review the recent…
We present preliminary results from a programme aimed at acquiring linear spectropolarimetry of magnetic A and B stars. Linear polarization in the spectral lines of these objects is due to the Zeeman effect, and should provide detailed new…
Basic aspects of the relationship between the magnetic field and polarized maser radiation are described with the emphasis on interpreting the observed spectra. Special attention is given to three issues--the limitations on the…
The origin of the magnetic field in massive O-type stars is still under debate. To model the physical processes responsible for the generation of O star magnetic fields, it is important to understand whether correlations between the…
We report about an ongoing photometric and spectroscopic monitoring survey of about 250 O- and 540 B-type stars in the southern Milky Way with the aim to determine the fraction of close binary systems as a function of mass and to determine…