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Related papers: Activity correlation and temporal variation of sma…

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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…

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

We aim to characterise the small-scale magnetic fields for a sample of 16 Sun-like stars and investigate the capabilities of the newly upgraded near-infrared (NIR) instrument CRIRES$^+$ at the VLT in the context of small-scale magnetic…

The large-scale magnetic field of solar-type stars reconstructed from their spectropolarimetric observations provide important insight into their underlying dynamo processes.We aim to investigate the temporal variability of the large-scale…

Solar and Stellar Astrophysics · Physics 2014-12-10 S. Boro Saikia , S. V. Jeffers , P. Petit , S. Marsden , J. Morin , C. P. Folsom

Observational constraints on stellar magnetic fields are essential to both stellar and planetary physics. Recent studies revealed the diversity and evolution of large-scale magnetic fields in low-mass stars. These large-scale fields only…

Solar and Stellar Astrophysics · Physics 2026-03-27 Paul I. Cristofari , Steven H. Saar , Aline A. Vidotto , Stefano Bellotti

Strong, globally-organized magnetic fields are found for a small fraction of O, B, and A stars. At the same time, many theoretical and indirect observational studies suggested ubiquitous presence of weak localized magnetic fields at the…

Solar and Stellar Astrophysics · Physics 2015-06-15 O. Kochukhov , N. Sudnik

Planets orbiting young, solar-type stars are embedded in a more energetic environment than that of the solar neighbourhood. They experience harsher conditions due to enhanced stellar magnetic activity and wind shaping the secular evolution…

Solar and Stellar Astrophysics · Physics 2025-07-22 S. Bellotti , T. Lueftinger , S. Boro Saikia , C. P. Folsom , P. Petit , J. Morin , M. Gudel , J. -F. Donati , E. Alecian

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…

M dwarfs are known to host magnetic fields, impacting exoplanet studies and playing a key role in stellar and planetary formation and evolution. Observations revealed the long-term evolution of the large-scale magnetic field reconstructed…

Solar and Stellar Astrophysics · Physics 2025-08-07 P. I. Cristofari , J. -F. Donati , S. Bellotti , É. Artigau , A. Carmona , C. Moutou , X. Delfosse , P. Petit , B. Finociety , J. Dias do Nascimento

The surface rotation rates of young solar-type stars decrease rapidly with age from the end of the pre-main sequence though the early main sequence. This suggests that there is also an important change in the dynamos operating in these…

Solar and Stellar Astrophysics · Physics 2015-06-17 C. P. Folsom , P. Petit , J. Bouvier , J. -F. Donati , J. Morin

By studying young magnetically active late-type stars, i.e. analogues to the young Sun, one can draw conclusions on the evolution of the solar dynamo. We determine the topology of the surface magnetic field and study the relation between…

Solar and Stellar Astrophysics · Physics 2016-03-02 Thomas Hackman , Jyri Lehtinen , Lisa Rosén , Oleg Kochukhov , Maarit J. Käpylä

Surface rotation rates of young solar-type stars display drastic changes at the end of the pre-main sequence through the early main sequence. This may trigger corresponding changes in the magnetic dynamos operating in these stars, which…

Solar and Stellar Astrophysics · Physics 2016-02-03 C. P. Folsom , P. Petit , J. Bouvier , J. Morin , A. Lèbre

The goal of this work is to study the magnetic fields of six young solar-analogue stars both individually, and collectively, to search for possible magnetic field trends with age. If such trends are found, they can be used to understand…

Solar and Stellar Astrophysics · Physics 2016-09-07 L. Rosén , O. Kochukhov , T. Hackman , J. Lehtinen

The surface magnetic fields of pre-main-sequence stars and zero-age main-sequence stars are notably strong, resulting in the generation of numerous spots and the emission of bright chromospheric lines. Rotational variations in magnetic…

Solar and Stellar Astrophysics · Physics 2025-04-08 Mai Yamashita , Yoichi Itoh , Shin Toriumi

The magnetic activity of the Sun changes with the solar cycle. Similar cycles are found in other stars as well, but their details are not known to a similar degree. Characterising stellar magnetic cycles is important for the understanding…

Solar and Stellar Astrophysics · Physics 2022-05-11 T. Willamo , J. J. Lehtinen , T. Hackman , M. J. Käpylä , O. Kochukhov , S. V. Jeffers , H. Korhonen , S. C. Marsden

The surface rotation rates of young solar-type stars vary rapidly with age from the end of the pre-main sequence through the early main sequence. Important changes in the dynamos operating in these stars may result from this evolution,…

Solar and Stellar Astrophysics · Physics 2016-01-27 C. P. Folsom , P. Petit , J. Bouvier , A. Lèbre , L. Amard , A. Palacios , J. Morin , J. -F. Donati , S. V. Jeffers , S. C. Marsden , A. A. Vidotto

Accurate tracers of the stellar magnetic field and rotation are cornerstones for the study of M dwarfs and for reliable detection and characterization of their exoplanetary companions. Such measurements are particularly challenging for old,…

We investigate the magnetic field at the surface of 48 red giants selected as promising for detection of Stokes V Zeeman signatures in their spectral lines. We use the spectropolarimeters Narval and ESPaDOnS to detect circular polarization…

We report intensive monitoring of the activity variability in the H$\alpha$ line for 10 Sun-like stars using the 1.88-m reflector at Okayama Branch Office, Subaru Telescope, during the last four years 2019-2022. Our aim was to investigate…

Solar and Stellar Astrophysics · Physics 2023-10-31 Sanghee Lee , Yuta Notsu , Bun'ei Sato

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…

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