English
Related papers

Related papers: Measuring the Coronal Magnetic Field with 2D Coron…

200 papers

A discrete tomography method has been developed that is able to reconstruct three-dimensional coronal mass ejection (CME) density structure. We test the method by producing synthetic coronagraph imagery for three events using the…

The Coronal Multi-channel Polarimeter (CoMP) obtains daily full-Sun above-the-limb coronal observations in linear polarization, allowing for the first time a diagnostic of the coronal magnetic field direction in quiescent prominence…

Solar and Stellar Astrophysics · Physics 2015-06-15 U. Bak-Steslicka , S. E. Gibson , Y. Fan , C. Bethge , B. Forland , L. A. Rachmeler

We use Coronal Multi-channel Polarimeter (CoMP) observations of propagating waves in the solar corona and Bayesian analysis to assess the evidence of models with resonant damping and foot-point wave power asymmetries. Two nested models are…

Solar and Stellar Astrophysics · Physics 2020-08-26 M. Montes-Solís , I. Arregui

At the Sun, the strongest magnetic fields are routinely detected at dark sunspots. The magnitude of the field is typically about 3000 G, with only a few exceptions that reported the magnetic field in excess of 5000 G. Given that the…

Solar and Stellar Astrophysics · Physics 2019-08-07 Sergey A. Anfinogentov , Alexey G. Stupishin , Ivan I. Mysh'yakov , Gregory D. Fleishman

We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 solar activity cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated…

Solar and Stellar Astrophysics · Physics 2015-06-15 G. J. D. Petrie

The solar coronal magnetic field is a pivotal element in the study of eruptive phenomena, and understanding its dynamic evolution has long been a focal point in solar physics. Numerical models, driven directly by observation data, serve as…

Solar and Stellar Astrophysics · Physics 2024-10-15 Zhi-Peng Liu , Chao-Wei Jiang , Xin-Kai Bian , Qing-Jun Liu , Peng Zou , Xue-Shang Feng

Coronal mass ejections (CMEs) are large-scale ejections of magnetized plasma from the Sun and are associated with the most extreme space weather events. The geoeffectiveness of a CME is primarily determined by the southward component of its…

Solar and Stellar Astrophysics · Physics 2024-07-09 Devojyoti Kansabanik , Angelos Voulidas

We use SDO/HMI and SOLIS/VSM photospheric magnetic field measurements to model the force-free coronal field above a solar active region, assuming magnetic forces to dominate. We take measurement uncertainties caused by, e.g., noise and the…

Solar and Stellar Astrophysics · Physics 2015-06-05 J. K. Thalmann , A. Pietarila , X. Sun , T. Wiegelmann

Understanding solar coronal magnetic fields is crucial to address the long-standing mysteries of the solar corona and solar wind. Although routine photospheric magnetic fields (MFs) are available for decades, coronal MFs are rarely…

Solar and Stellar Astrophysics · Physics 2021-12-21 K. Sasikumar Raja , Suresh Venkata , Jagdev Singh , B. Raghavendra Prasad

Time-evolving magnetohydrodynamic (MHD) coronal modeling, driven by a series of time-dependent photospheric magnetograms, represents a new generation of coronal simulations. This approach offers greater realism compared to traditional…

Measuring the physical parameters of Coronal Mass Ejections (CMEs), particularly their entrained magnetic field, is crucial for understanding their physics and for assessing their geo-effectiveness. At the moment, only remote sensing…

Solar and Stellar Astrophysics · Physics 2020-08-13 Surajit Mondal , Divya Oberoi , Angelos Vourlidas

Coronagraph observations provide key information about the orientation of the Sun's magnetic field. Previous studies used various algorithms to segment quasi-radial features in coronagraph images and approximate their local plane-of-sky…

Solar and Stellar Astrophysics · Physics 2026-01-26 Christopher E. Rura , Vadim M. Uritsky , Shaela I. Jones , Cooper Downs , Nathalia Alzate , Charles N. Arge

We present a unified method to derive both solar wind velocities and coronal electron densities in the near-Sun corona using Doppler spectral broadening of spacecraft radio signals. The method is generalized to be frequency independent…

Solar and Stellar Astrophysics · Physics 2026-03-26 Keshav Aggarwal , R. K. Choudhary , Abhirup Datta , Roopa M. V. , Takeshi Imamura , Hiroki Ando

Coronal dimmings are distinct phenomena associated to coronal mass ejections (CMEs). The study of coronal dimmings and the extraction of their characteristic parameters helps us to obtain additional information of CMEs, especially on the…

Solar and Stellar Astrophysics · Physics 2018-04-04 Karin Dissauer , Astrid M. Veronig , Manuela Temmer , Tatiana Podladchikova , Kamalam Vanninathan

A new method for reconstruction of coronal magnetic fields as force-free fields (FFFs) is presented. Our method employs poloidal and toroidal functions to describe divergence-free magnetic fields. This magnetic field representation…

Solar and Stellar Astrophysics · Physics 2022-10-04 Sibaek Yi , G. S. Choe , Kyung-Suk Cho , Sami K. Solanki , Jörg Büchner

Adopting the thermal free-free emission mechanism, the coronal and chromospheric magnetic fields are derived from the polarization and spectral observations with the Nobeyama Radioheliograph at 1.76 cm. The solar active regions (AR) located…

Solar and Stellar Astrophysics · Physics 2018-02-14 A. Mouner , Abdelrazek M. K. Shaltout , M. M. Beheary , K. A. K. Gadallah , K. A. Edris

Propagating slow waves in coronal loops exhibit a damping which depends upon the frequency of the waves. In this study we aim to investigate the relationship of the damping length (L$_d$) with the frequency of the propagating wave. We…

Solar and Stellar Astrophysics · Physics 2016-03-23 Sudip Mandal , Norbert Magyar , Ding Yuan , Tom Van Doorsselaere , Dipankar Banerjee

Dust polarization is a powerful tool for studying the magnetic field properties in the interstellar medium (ISM). However, it does not provide a direct measurement of its strength. Different methods havebeen developed which employ both…

Astrophysics of Galaxies · Physics 2021-04-07 Raphael Skalidis , Konstantinos Tassis

The hemispheric pattern of solar filaments is considered using newly-developed simulations of the real photospheric and 3D coronal magnetic fields over a 6-month period, on a global scale. The magnetic field direction in the simulation is…

Astrophysics · Physics 2015-05-13 A. R. Yeates , D. H. Mackay , A. A. van Ballegooijen

In contrast to the situation in a laboratory, the study of the solar atmosphere has to be pursued without direct access to the physical conditions of interest. Information is therefore incomplete and uncertain and inference methods need to…

Solar and Stellar Astrophysics · Physics 2018-01-24 I. Arregui