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Related papers: Complexity of magnetic fields on red dwarfs

200 papers

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…

Solar and Stellar Astrophysics · Physics 2015-06-03 Lisa Rosén , Oleg Kochukhov , Gregg A. Wade

Deriving metallicities for solar-like stars follows well-established methods, but for cooler stars such as M dwarfs, the determination is much more complicated due to forests of molecular lines that are present. Several methods have been…

M dwarfs host strong magnetic fields that can be measured using several complementary techniques. However, the impact of key methodological choices on Zeeman broadening diagnostics has not been systematically quantified. We assess the…

Solar and Stellar Astrophysics · Physics 2026-05-19 I. Amateis , O. Kochukhov , A. Hahlin

The characterization of magnetic fields within molecular clouds is fundamental to understanding star formation processes. Accurately gauging the three-dimensional structure of these fields presents a challenge, as observational techniques…

Astrophysics of Galaxies · Physics 2024-11-18 Brandon Shane , Blakesley Burkhart , Laura Fissel , Susan E. Clark , Philip Mocz , Michael M. Foley

M dwarfs are the most abundant stars in the Galaxy and exhibit diverse magnetic behaviours. Understanding their large-scale magnetic fields is essential to study stellar dynamos and assess the impact of magnetic activity on planetary…

Strong magnetic fields are observed in a substantial fraction of upper main sequence stars and white dwarfs. Many such stars are observed to exhibit photometric modulations as the magnetic poles rotate in and out of view, which could be a…

Solar and Stellar Astrophysics · Physics 2023-02-22 Jim Fuller , Stephane Mathis

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…

We construct models for strongly-magnetized neutron star atmospheres composed of mid-Z elements (carbon, oxygen and neon) with magnetic fields B=10^{12}-10^{13} G and effective temperatures Teff=(1-5)*10^6 K; this is done by first…

Astrophysics · Physics 2008-11-26 Kaya Mori , Wynn C. G. Ho

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…

Astrophysics · Physics 2008-11-26 A. Reiners , G. Basri

The solar photospheric magnetic field is highly structured owing to its interaction with the convective flows. Its local structure has a strong influence on the profiles of spectral lines not only by virtue of the Zeeman effect, but also…

Solar and Stellar Astrophysics · Physics 2014-08-13 Benjamin Beeck , Manfred Schüssler , Ansgar Reiners

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…

Solar and Stellar Astrophysics · Physics 2015-05-30 D. Shulyak , A. Seifahrt , A. Reiners , O. Kochukhov , N. Piskunov

We investigate the possibility of measuring magnetic field strength in G-band bright points through the analysis of Zeeman polarization in molecular CH lines. To this end we solve the equations of polarized radiative transfer in the G band…

Astrophysics · Physics 2009-11-10 H. Uitenbroek , E. Miller-Ricci , A. Asensio Ramos , J. Trujillo Bueno

The strength of the total magnetic field in our Milky Way from radio Zeeman and synchrotron measurements is about 6 muG near the Sun and several mG in dense clouds, pulsar wind nebulae, and filaments near the Galactic Center. Diffuse…

Astrophysics · Physics 2009-11-13 Rainer Beck

We present an analysis of photometric, spectroscopic and spectropolarimetric data of the nearby, cool, magnetic DZ white dwarf PM J08186-3110. High dispersion spectra show the presence of Zeeman splitted spectral lines due to the presence…

Solar and Stellar Astrophysics · Physics 2020-11-11 Adela Kawka , Stéphane Vennes , Nicole F. Allard , T. Leininger , F. X. Gadéa

Context. Being the most numerous and oldest stars in the galaxy, M dwarfs are objects of great interest for exoplanet searches. The presence of molecules in their atmosphere complicates our understanding of their atmospheric properties. But…

Solar and Stellar Astrophysics · Physics 2019-02-20 A. S. Rajpurohit , F. Allard , S. Rajpurohit , R. Sharma , G. D. C. Teixeira , O. Mousis , R. Kamlesh

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,…

Solar and Stellar Astrophysics · Physics 2020-03-25 O. Kochukhov , T. Hackman , J. J. Lehtinen , A. Wehrhahn

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…

Solar and Stellar Astrophysics · Physics 2025-04-02 Veronique Petit , Mary E. Oksala

Many stars evolve into magnetic white dwarfs, and observations may help to understand when the magnetic field appears at the stellar surface, if and how it evolves during the cooling phase, and what are the mechanisms that generate it.…

Solar and Stellar Astrophysics · Physics 2021-10-04 S. Bagnulo , J. D. Landstreet

Magnetic and energetic properties are presented for 17 dense cores within a few hundred pc of the Sun. Their plane-of-sky field strengths are estimated from the dispersion of polarization directions, following Davis, Chandrasekhar and Fermi…

Astrophysics of Galaxies · Physics 2021-08-18 Philip C. Myers , Shantanu Basu

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…

Solar and Stellar Astrophysics · Physics 2015-06-24 D. Shulyak , D. Sokoloff , L. Kitchatinov , D. Moss