相关论文: Magnetic fields in M-dwarfs: quantitative results …

We present first quantitative results of the surface magnetic field measurements in selected M-dwarfs based on detailed spectra synthesis conducted simultaneously in atomic and molecular lines of the FeH Wing-Ford $F^4\,\Delta-X^4\,\Delta$…

M-type stars exhibit strong magnetic fields towards decreasing effective temperatures. The measurement of these fields is complicated due to missing indicators. Molecular FeH lines provide an excellent means to determine magnetic field…

Magnetic fields play a fundamental role for interior and atmospheric properties of M dwarfs and greatly influence terrestrial planets orbiting in the habitable zones of these low-mass stars. Determination of the strength and topology of…

Magnetic fields in cool stars can be investigated by measuring Zeeman line broadening and polarization in atomic and molecular lines. Similar to the Sun, these fields are complex and height-dependent. Many molecular lines dominating M-dwarf…

M dwarfs are known to generate the strongest magnetic fields among main-sequence stars with convective envelopes, but the link between the magnetic fields and underlying dynamo mechanisms, rotation, and activity still lacks a consistent…

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…

We present the first direct magnetic field measurements on M dwarfs cooler than spectral class M4.5. Utilizing a new method based on the effects of a field on the FeH band near 1 micron, we obtain information on whether the integrated…

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…

Magnetic fields have been detected on stars across the H-R diagram and substellar objects either directly by their effect on the formation of spectral lines, or through the activity phenomena they power which can be observed across a large…

We present a new method for direct measurement of magnetic fields on ultracool stars and brown dwarfs. It takes advantage of the Wing-Ford band of FeH, which are seen throughout the M and L spectral types. These molecular features are not…

M dwarfs are the most numerous stars in our Galaxy with masses between approximately 0.5 and 0.1 solar mass. Many of them show surface activity qualitatively similar to our Sun and generate flares, high X-ray fluxes, and large-scale…

Magnetic activity in M-dwarfs present enigmatic questions: On the one hand they have higher field strengths and larger filling factors than the magnetic field on the Sun, on the other hand, they are fully convective and their atmospheres…

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…

Magnetic fields in the upper atmospheres of solar-like stars are believed to provide an enormous amount of energy to power the hot coronae and drive large-scale eruptions that could impact the habitability of planetary systems around these…

Massive stars are crucial building blocks of galaxies and the universe, as production sites of heavy elements and as stirring agents and energy providers through stellar winds and supernovae. The field of magnetic massive stars has seen…

White dwarfs are excellent research laboratories as they reach temperatures, pressures, and magnetic fields that are unattainable on Earth. To better understand how these three physical parameters interact with each other and with other…

Stellar dynamo processes can be explored by measuring the magnetic field. This is usually obtained using the atomic and molecular Zeeman effect in spectral lines. While the atomic Zeeman effect can only access warmer regions, the use of…

Stellar Magnetism affects all spectral types and exists and varies throughout the evolution of stars. Magnetic fields can affect not only the interior of stars, but also their circumstellar environments. In this chapter, we concentrate on…

Recent progress in observational studies of magnetic activity in M dwarfs urgently requires support from ideas of stellar dynamo theory. We propose a strategy to connect observational and theoretical studies. In particular, we suggest four…

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…