Related papers: Stellar longitudinal magnetic field determination …
Context. Recent high angular resolution polarimetric continuum observations of circumstellar disks provide new insights into their magnetic field. However, direct constraints are limited to the plane of sky component of the magnetic field.…
Measurements of interplanetary magnetic fields have long relied on spacecraft measurements, which provide only in-situ sampling and therefore cannot capture the global magnetic structure. Faraday rotation of radio signals extends in-situ…
Given that dynamically significant magnetic fields in at least some massive stars have now been measured, our contribution addresses the question, to what extent can fields be directly detected in circumstellar gas? The question speaks…
Magnetic activity and rotation are known to be intimately linked for low-mass stars. Understanding rotation evolution over the stellar lifetime is therefore an important goal within stellar astrophysics. In recent years, there has been…
Magnetic fields are an important ingredient to cool star physics, and there is great interest in measuring fields and their geometry in order to understand stellar dynamos and their influence on star formation and stellar evolution. During…
In this chapter, we give a brief introduction into the use of the Zeeman effect in astronomy and the general detection of magnetic fields in stars, concentrating on the use of FORS2 for longitudinal magnetic field measurements.
Direct measurements of magnetic fields in low-mass stars of spectral class M have become available during the last years. This contribution summarizes the data available on direct magnetic measurements in M dwarfs from Zeeman analysis in…
High-dispersion, archival spectra of magnetic Ap stars with resolved Zeeman components in Stokes I are used to derive a simple relation that can be utilised to estimate the mean surface field strengths of stars with v sin i > 10 km/s. For…
We present new magnetic field measurements of the K2 main-sequence star $\epsilon$ Eridani based on principal components analysis (PCA) line-profile reconstructions. The aim of this paper is to quantify the surface-averaged magnetic field…
When using a recently developed method of Doppler-Zeeman mapping (Vasilchenko et al., 1996) for analysis of a real star and real observational data, we are confronted with limitations due to the model simplifications and unavoidable errors…
This review discusses the problem of reconstruction of surface magnetic field topologies of early-type stars with a focus on mapping methods utilising information content of high-resolution spectropolarimetric observations. Basic principles…
Magnetic fields are ubiquitous in active cool stars but they are in general complex and weak. Current Zeeman Doppler imaging (ZDI) studies of cool star magnetic fields chiefly employ circular polarization observations because linear…
The measurement of Zeeman splitting in spectral lines---both in emission and absorption---can provide direct estimates of the magnetic field strength and direction in atomic and molecular clouds, both in our own Milky Way and in external…
Zeeman Doppler imaging has successfully mapped the large-scale magnetic fields of stars over a large range of spectral types, rotation periods and ages. When observed over multiple epochs, some stars show polarity reversals in their global…
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…
Numerous attempts to estimate the rate at which low-mass stars lose angular momentum over their lifetimes exist in the literature. One approach is to use magnetic maps derived from Zeeman-Doppler imaging (ZDI) in conjunction with so-called…
Magnetic fields are important for stellar photospheres and magnetospheres, influencing photospheric physics and sculpting stellar winds. Observations of stellar magnetic fields are typically made in the visible, although infrared…
Global magnetic fields of active solar-like stars are nowadays routinely detected with spectropolarimetric measurements and are mapped with Zeeman-Doppler imaging (ZDI). However, due to the cancellation of opposite field polarities,…
The degree to which the formation and evolution of clouds and filaments in the interstellar medium is regulated by magnetic fields remains an open question. Yet the fundamental properties of the fields (strength and 3D morphology) are not…
Stellar magnetic dynamos are driven by rotation, rapidly rotating stars produce stronger magnetic fields than slowly rotating stars do. The Zeeman effect is the most important indicator of magnetic fields, but Zeeman broadening must be…