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Related papers: Super-strong Magnetic Field in Sunspots

200 papers

Magnetic fields in pre main sequence stars regulate angular momentum evolution, drive magnetic activity, and modify stellar structure, yet their surface distributions remain poorly constrained. Traditional single component Zeeman broadening…

Solar and Stellar Astrophysics · Physics 2025-09-26 Facundo Pérez Paolino , Lynne Hillenbrand , Jeff Bary

Solar activity seems quite understandable when considered on the scales comparable with a solar cycle, i.e. about 11 years, and on a short time scale of about a year. A solar cycle looks basically (anti)symmetric with respect to the solar…

Solar and Stellar Astrophysics · Physics 2025-08-08 V. N. Obridko , A. S. Shibalova , D. D. Sokoloff , I. M. Livshits

Solar activity can be witnessed in the form of sunspots and active regions, where the magnetic field is enhanced by up to a factor 1000 as compared to that of the quiet Sun. In addition, solar activity manifests itself in terms of flares,…

Solar and Stellar Astrophysics · Physics 2025-07-25 Gottfried Mann , Frédéric Schuller

Regardless of the physical origin of stellar magnetic fields - fossil or dynamo induced - an inclination angle between the magnetic and rotation axes is very often observed. Absence of observational evidence in this direction in the solar…

Solar and Stellar Astrophysics · Physics 2018-04-27 A. Pastor Yabar , M. J. Martínez González , M. Collados

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…

Kilogauss-strength magnetic fields are often observed in intergranular lanes at the photosphere in the quiet Sun. Such fields are stronger than the equipartition field $B_e$, corresponding to a magnetic energy density that matches the…

Astrophysics · Physics 2009-11-13 P. J. Bushby , S. M. Houghton , M. R. E. Proctor , N. O. Weiss

The magnetic fields of the quiet Sun cover at any time more than 90\% of its surface and their magnetic energy budget is crucial to explain the thermal structure of the solar atmosphere. One of the possible origins of these fields is due to…

Solar and Stellar Astrophysics · Physics 2017-08-09 E. Khomenko , N. Vitas , M. Collados , A. de Vicente

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

The high spatial, temporal and spectral resolution achieved by Hinode instruments give much better understanding of the behavior of some elusive solar features, such as pores and naked sunspots. Their fast evolution and, in some cases,…

Solar and Stellar Astrophysics · Physics 2012-02-06 A. Sainz Dalda , S. Vargas Dominguez , T. D. Tarbell

The recent solar minimum and rise phase of solar cycle 24 have been unlike any period since the early 1900s. This article examines some of the properties of sunspot umbrae over the last 17 years with three different instruments on the…

Solar and Stellar Astrophysics · Physics 2015-11-24 Fraser T. Watson , Matthew J. Penn , William C. Livingston

We present an explanation for the well-known observation that complexity of the solar magnetic field is a necessary ingredient for strong activity such as large eruptive flares. Our model starts with the standard picture for the energy…

Astrophysics · Physics 2009-10-30 Spiro K. Antiochos

This paper examines the generation of seed magnetic fields due to the growth of cosmological perturbations. In the radiation era, different rates of scattering from photons induce local differences in the ion and electron density and…

Astrophysics · Physics 2008-11-26 E. R. Siegel , J. N. Fry

The equilibrium configuration of very small magnetic fluxtubes in an intergranular environment automatically produces kG magnetic field strengths. We argue that such process takes place in the Sun and complements the convective collapse…

Astrophysics · Physics 2009-11-06 J. Sanchez Almeida

A light bridge is a prominent structure commonly observed within a sunspot. Its presence usually triggers a wealth of dynamics in a sunspot, and has a lasting impact on sunspot evolution. However, the fundamental structure of light bridges…

Solar and Stellar Astrophysics · Physics 2020-04-15 Song Feng , Yuhu Miao , Ding Yuan , Zhongquan Qu , Valery M. Nakariakov

Magnetic fields are ubiquitous in the Universe. The Sun's magnetic field drives the solar wind and causes solar flares and other energetic surface phenomena that profoundly affect space weather here on Earth. The first magnetic field in a…

It was empirically determined that the umbra-penumbra boundaries of stable sunspots are characterized by a constant value of the vertical magnetic field. We analyzed the evolution of the photospheric magnetic field properties of a decaying…

Solar and Stellar Astrophysics · Physics 2018-12-19 M. Benko , S. J. González Manrique , H. Balthasar , P. Gömöry , C. Kuckein , J. Jurčák

The scattering of dark matter particles within the Sun's hot plasma can lead to acceleration of dark matter, producing a high-energy solar-reflected DM flux detectable in ground-based experiments. In the vector portal model, interactions…

High Energy Physics - Phenomenology · Physics 2025-10-22 Haoming Nie

Strong magnetic fields are naturally self-generated in high-power, laser-solid interactions through the Biermann-battery mechanism. This work experimentally characterizes the 3D location and strength of these fields, rather than…

The negative effective magnetic pressure instability operates on scales encompassing many turbulent eddies and is here discussed in connection with the formation of active regions near the surface layers of the Sun. This instability is…

Solar and Stellar Astrophysics · Physics 2013-09-10 Koen Kemel , Axel Brandenburg , Nathan Kleeorin , Dhrubaditya Mitra , Igor Rogachevskii

Observations with the Hinode space observatory led to the discovery of predominantly horizontal magnetic fields in the photosphere of the quiet internetwork region. Here we investigate realistic numerical simulations of the surface layers…

Astrophysics · Physics 2009-11-13 O. Steiner , R. Rezaei , W. Schaffenberger , S. Wedemeyer-Böhm