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Related papers: A search for magnetic fields in the variable HgMn …

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We aim to test the reliability of determining the line-of-sight magnetic field from a 3D MHD simulation of a unipolar region. In contrast to earlier similar studies, we consider the full solar disk, i.e. considering the full centre-to-limb…

Solar and Stellar Astrophysics · Physics 2024-10-23 Jonas Sinjan , Sami K. Solanki , Johann Hirzberger , Tino L. Riethmüller , Damien Przybylski

Stars with radiative envelopes, specifically the upper main sequence chemically peculiar (Ap) stars, were among the first objects outside our solar system for which surface magnetic fields have been detected. Currently magnetic Ap stars…

Solar and Stellar Astrophysics · Physics 2015-06-17 O. Kochukhov

The structure of the photospheric vector magnetic field below a dark filament on the Sun is studied using the observations of the Spectro-Polarimeter attached to the Solar Optical Telescope onboard Hinode. Special attention is paid to…

Solar and Stellar Astrophysics · Physics 2019-03-20 Takaaki Yokoyama , Yukio Katsukawa , Masumi Shimojo

Starspots are usually associated with the action of magnetic fields at the stellar surfaces. However, recently an inhomogeneous chemical distribution of mercury was found for the mercury-manganese (HgMn) star alpha And -- a well-established…

Astrophysics · Physics 2009-11-11 O. Kochukhov , N. Piskunov , M. Sachkov , D. Kudryavtsev

We examine the hypothesis that multipolar magnetic fields advected by photospheric granules can contribute heating to the active chromosphere and corona. On 28 September 2020 the GRIS and HiFI+ instruments at the GREGOR telescope obtained…

Solar and Stellar Astrophysics · Physics 2024-05-14 Philip Judge , Lucia Kleint , Christoph Kuckein

Using an axisymmetric numerical code, we perform an extensive study of the magnetic field configurations in non-rotating neutron stars, varying the mass, magnetic field strength and the equation of state. We find that the monopolar…

Nuclear Theory · Physics 2019-06-12 Debarati Chatterjee , Jerome Novak , Micaela Oertel

Massive star winds are important contributors to the energy, momentum and chemical enrichment of the interstellar medium. Strong, organized and predominantly dipolar magnetic fields have been firmly detected in a small subset of massive…

Solar and Stellar Astrophysics · Physics 2020-04-29 Melissa Munoz , Gregg Wade , Daniel Faes , Alex Carciofi

We investigate the magnetic dichotomy between Ap/Bp and other A-type stars by carrying out a deep spectropolarimetric study of Am and HgMn stars. Using the NARVAL spectropolarimeter at the Telescope Bernard Lyot (Observatoire du Pic du…

Solar and Stellar Astrophysics · Physics 2015-05-19 M. Auriere , G. A. Wade , F. Lignieres , A. Hui-Bon-Hoa , J. D. Landstreet , I. Iliev , J. -F. Donati , P. Petit , T. Roudier , S. Theado

The strengths of magnetic fields in interstellar gas clouds are obtained through observations of the circular polarization of spectral line radiation. Irregularities in this magnetic field may be present due to turbulence, waves or perhaps…

Astrophysics · Physics 2009-10-31 W. D. Watson , D. S. Wiebe , R. M. Crutcher

We employ high-spatial resolution spectropolarimetric observations from the Solar Optical Telescope on-board the Hinode spacecraft to investigate the fine structure of the penumbral magnetic fields. The Stokes vector of two neutral iron…

Astrophysics · Physics 2009-11-13 J. M. Borrero , B. W. Lites , S. K. Solanki

Magnetic field investigations of Sun-like stars, using Zeeman splitting of non-polarised spectra, in the optical and H-band have found significantly different magnetic field strengths for the same stars, the cause of which is currently…

The magnetic chemically peculiar (CP2) stars of the upper main sequence are well-suited for investigating the impact of magnetic fields on the surface layers of stars, which leads to abundance inhomogeneities (spots) resulting in…

Solar and Stellar Astrophysics · Physics 2015-12-15 K. Bernhard , S. Huemmerich , E. Paunzen

Recently, there have been some reports of unusually strong photospheric magnetic fields (which can reach values of over 7 kG) inferred from Hinode SOT/SP sunspot observations within penumbral regions. These superstrong penumbral fields are…

Solar and Stellar Astrophysics · Physics 2019-10-30 A. Siu-Tapia , A. Lagg , M. van Noort , M. Rempel , S. K. Solanki

It is essential for the understanding of stellar structure models of high mass stars to explain why constant stars, non-pulsating chemically peculiar hot Bp stars and pulsating stars co-exist in the slowly pulsating B stars and beta Cephei…

Astrophysics · Physics 2009-11-11 M. Briquet , S. Hubrig , M. Schoeller , P. De Cat

The forthcoming new-generation radio telescope SKA (Square Kilometre Array) and its precursors will provide a rapidly growing number of polarized radio sources. Our analysis aims on what can be learned from these sources concerning the…

Astrophysics · Physics 2009-11-13 Rodion Stepanov , Tigran G. Arshakian , Rainer Beck , Peter Frick , Marita Krause

Early magnetographic observations indicated that magnetic field in the solar photosphere has unresolved small-scale structure. Near-infrared and optical data with extremely high spatial resolution show that these structures have scales of…

Solar and Stellar Astrophysics · Physics 2018-11-21 M. Gordovskyy. , S. Shelyag , P. K. Browning , V. G. Lozitsky

We present high-precision spectro-polarimetric data with high spatial resolution (0.4$''$) of the very quiet Sun at 1.56$\mu$m obtained with the GREGOR telescope to shed some light on this complex magnetism. Half of our observed quiet-Sun…

We report magnetic field measurements spanning about 15 years of four massive ($7.5-15 M_\odot$) supergiant stars: $\alpha$ Per (HD\,20902, F5Iab), $\alpha$ Lep (HD\,36673A, F0Ib), $\eta$ Leo (HD\,87737, A0Ib) and 13 Mon (HD\,46300, A1Ib).…

Solar and Stellar Astrophysics · Physics 2025-07-02 Gregg Wade , Mary Oksala , Coralie Neiner , Etienne Boucher , James Barron

Some massive stars possess strong magnetic fields that confine plasma in the circumstellar environment. These \textit{magnetospheres} have been studied spectroscopically, photometrically and, more recently, interferometrically. Here we…

Solar and Stellar Astrophysics · Physics 2015-06-15 Alex C. Carciofi , Daniel M. Faes , Richard H. D. Townsend , Jon E Bjorkman

We investigate the orientation of the photospheric magnetic fields in the solar polar region using observations from the Helioseismic and Magnetic Imager (HMI). Inside small patches of significant polarization, the inferred magnetic field…

Solar and Stellar Astrophysics · Physics 2021-06-04 Xudong Sun , Yang Liu , Ivan Milić , Ana Belén Griñón Marín