Related papers: Complexity of magnetic fields on red dwarfs
We present the results of a new survey of 23 molecular clouds for the Zeeman effect in OH undertaken with the ATNF Parkes 64-m radio telescope and the NRAO Green Bank 43-m radio telescope. The Zeeman effect was clearly detected in the cloud…
We report the results of an observational study aimed at searching for magnetic pulsating hot stars suitable for magneto-asteroseismology. A sample of sixteen chemically peculiar stars was selected and analysed using both high-resolution…
All cool main sequence stars including our Sun are thought to have magnetic fields. Observations of the Sun revealed that even in quiet regions small-scale turbulent magnetic fields are present. Simulations further showed that such magnetic…
Magnetic fields with strengths ranging from 300 to 500 kG have recently been discovered in a group of four extremely similar helium-enriched hot subdwarf (He-sdO) stars. Besides their strong magnetic fields, these He-sdO stars are…
The dynamical state of star-forming molecular clouds cannot be understood without determining the structure and strength of their magnetic fields. Measurements of polarized far-infrared radiation from thermally aligned dust grains are used…
Context. M subdwarfs are metal poor and cool stars. They are important probes of the old galactic populations. However, they remain elusive due to their low luminosity. Observational and modeling efforts are required to fully understand…
The dynamo processes in cool active stars generate complex magnetic fields responsible for prominent surface stellar activity and variability at different time scales. For a small number of cool stars magnetic field topologies were…
Based on detailed spectral synthesis we carry out quantitative measurements of the strength and complexity of surface magnetic fields in the four well-known M-dwarfs GJ 388, GJ 729, GJ 285, and GJ 406 populating the mass regime around the…
Our knowledge of the magnetism in white dwarfs is based on an observational dataset that is biased in favour of stars with very strong magnetic fields. Most of the field measurements available in the literature have a relatively low…
We present an accurate quantum mechanical study of molecule-molecule collisions in the presence of a magnetic field. The work focusses on the analysis of elastic scattering and spin relaxation in collisions of O2(3Sigma_g) molecules at cold…
Magnetic hot stars refer to the stars, which effective temperatures approximately in the range from 7,000 to 50,000 K, and with large-scale globally organized magnetic fields. These magnetic fields exhibit strengths ranging from tens of…
We empirically determine effective temperatures and bolometric luminosities for a large sample of nearby M dwarfs, for which high accuracy optical and infrared photometry is available. We introduce a new technique which exploits the flux…
Context: There is now growing evidence that some brown dwarfs (BDs) have very strong magnetic fields, and yet their surface temperatures are so low that the coupling is expected to be small between the matter and the magnetic field in the…
In recent years, the development of spectropolarimetric techniques deeply modified our knowledge of stellar magnetism. In the case of solar-type stars, the challenge is to measure a geometrically complex field and determine its evolution…
We determine magnetic fields from the photosphere to the upper chromosphere combining data from the Hinode satellite and the CLASP2.1 sounding rocket experiment. CLASP2.1 provided polarization profiles of the Mg~{|sc ii} $h$ and $k$ lines,…
A model of magnetic field structure is presented to help test the prevalence of flux freezing in star-forming clouds of various shapes, orientations, and degrees of central concentration, and to estimate their magnetic field strength. The…
The complex spectropolarimetric patterns around strong chromospheric lines, the result of subtle spectroscopic and transport mechanisms, are sensitive, sometimes in unexpected ways, to the presence of magnetic fields in the chromosphere,…
We present here the first results of a spectropolarimetric analysis of a small sample (about 20) of active stars ranging from spectral type M0 to M8, which are either fully-convective or possess a very small radiative core. This study aims…
Characteristics of the depression contribution functions are studied for the Stokes line profiles formed in a magnetic field. The form of the depression functions depends mainly on the strength of splitting and the Zeeman component…
We present an analysis of high-resolution ($R \sim 50,000$) infrared K-band echelle spectra of 14 T Tauri stars in the Orion Nebula Cluster. We model Zeeman broadening in three magnetically sensitive \ion{Ti}{1} lines near $2.2\ \mu$m and…