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We highlight the main results of a radiative transfer investigation on the magnetic sensitivity of the solar Mg ii k resonance line at 2795.5 angstrom, accounting for the joint action of the Hanle and Zeeman effects as well as partial…

Solar and Stellar Astrophysics · Physics 2016-11-09 Ernest Alsina Ballester , Luca Belluzzi , Javier Trujillo Bueno

The solar wind is highly turbulent, and intermittency effects are observed for fluctuations within the inertial range. By analyzing magnetic field spectra and fourth-order moments, we perform a comparative study of turbulence and…

Space Physics · Physics 2025-02-11 Shiladittya Mondal , Supratik Banerjee , Luca Sorriso-Valvo

The vertical stratification of the magnetic field strength in sunspot penumbrae is investigated by means of spectropolarimetric observations at high spatial resolution from the Hinode spacecraft. Assuming that the magnetic field changes…

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

Our knowledge of the presence and the strength of magnetic fields in massive O and B-type stars remains very poor. Recent observations indicate that the presence of magnetic fields is responsible for a wide range of phenomena observed in…

Solar and Stellar Astrophysics · Physics 2013-09-24 S. Hubrig , M. Schoeller , I. Ilyin , G. Lo Curto

We study the dynamics of shock waves observed in the umbra of a sunspot using the spectroscopic observations from the Interface Region Imaging Spectrometer (IRIS). The presence of the shock significantly deforms the shape of the spectral…

Solar and Stellar Astrophysics · Physics 2021-01-27 Pradeep Kayshap , Durgesh Tripathi , P. Jelinek

The physical parameters of the sunspot are not fully understood, especially the height dependence of the magnetic field. So far, it is also an open question as to which heights the He I 1083 nm spectral line is formed at. Our aim is to…

Solar and Stellar Astrophysics · Physics 2024-06-12 M. Benko , H. Balthasar , P. Gömöry , C. Kuckein , S. J. González Manrique

Context. It has been reported that the boundary between the umbra and the penumbra of sunspots occurs at a canonical value of the strength of the vertical magnetic field, independently of the size of the spot. This critical field strength…

Solar and Stellar Astrophysics · Physics 2020-07-22 B. Löptien , A. Lagg , M. van Noort , S. K. Solanki

Over the past five years, 2010-2015, we have observed, in the near infrared (IR), the maximum magnetic field strengths for 4145 sunspot umbrae. Herein we distinguish field strengths from field flux. (Most solar magnetographs measure flux).…

Solar and Stellar Astrophysics · Physics 2016-04-12 William Livingston , Fraser Watson

Light walls, as ensembles of oscillating bright structures rooted in sunspot light bridges, have not been well studied, although they are important for understanding sunspot properties. Using the Interface Region Imaging Spectrograph and…

Solar and Stellar Astrophysics · Physics 2017-07-19 Shuhong Yang , Jun Zhang , Robertus Erdélyi , Yijun Hou , Xiaohong Li , Limei Yan

Searches for small exoplanets around solar-type stars are limited by stellar physical variability. While chromospheric variability is well studied, observing, modeling. and understanding the much smaller fluctuations in photospheric…

Solar and Stellar Astrophysics · Physics 2024-07-03 Dainis Dravins , Hans-Günter Ludwig

In the framework of turbulence dynamo, flow motions amplify a weak seed magnetic field through the stretching of field lines. Although the amplification process has been a topic of active research, less attention has been paid to the length…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Jungyeon Cho , Dongsu Ryu

Radio quasar sightlines with strong MgII absorption lines display statistically enhanced Faraday Rotation Measures (RM) indicating the presence of additional magneto-active plasma with respect to sightlines free of such absorption. In this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 M. L. Bernet , F. Miniati , S. J. Lilly

Solar pores are strongly magnetized regions lacking a photospheric penumbra and characterized by predominantly vertical magnetic fields. We present a multi-line study of flashes in a solar pore using high-resolution observations from the…

Solar and Stellar Astrophysics · Physics 2026-02-11 Sandeep Dubey , Christian Beck , Rahul Yadav , Tobias Felipe , Shibu K Mathew

Recent calculations, concerning the magnetism of uranium in the U/Fe multilayer system have described the spatial dependence of the 5f polarization that might be expected. We have used the x-ray resonant magnetic reflectivity technique to…

Solar flares are known to leave imprints on the magnetic field at the photosphere, often manifested as an abrupt and permanent change in the downward-directed Lorentz force in localized areas inside the active region. Our study aims to…

Solar and Stellar Astrophysics · Physics 2026-04-16 Samriddhi Sankar Maity , Ranadeep Sarkar , Piyali Chatterjee , Nandita Srivastava

In this study, we investigate magnetic properties of umbra of magneto-conjugate leading and following sunspots, i.e. connected through magnetic field lines. We established dependences between individual sunspot umbra field characteristics,…

Solar and Stellar Astrophysics · Physics 2017-11-27 Iu. S. Zagainova , V. G. Fainshtein , G. V. Rudenko , V. N. Obridko

In this work, we studied oscillation parameters in faculae above magnetic knots and in the adjacent to them areas. Using SDO data we analysed oscillations in magnetic strength, Doppler velocity, and intensity signals for the lower…

Solar and Stellar Astrophysics · Physics 2016-08-17 Andrei A. Chelpanov , Nikolai I. Kobanov , Dmitry Y. Kolobov

Filtergrams obtained in Ca II H, Ca II K and H-alpha are often employed as diagnostics of the solar chromosphere. However, the vastly disparate appearance between the typical filtergrams in these different lines calls into question the…

Astrophysics · Physics 2015-05-13 K. P. Reardon , H. Uitenbroek , G. Cauzzi

We have been monitoring yearly variation in the Sun's polar magnetic fields with the Solar Optical Telescope aboard {\it Hinode} to record their evolution and expected reversal near the solar maximum. All magnetic patches in the magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-05 D. Shiota , S. Tsuneta , M. Shimojo , N. Sako , D. Orozco Suárez , R. Ishikawa

Sunspots, which harbor both magnetic polarities within one penumbra, are called delta-spots. They are often associated with flares. Nevertheless, there are only very few detailed observations of the spatially resolved magnetic field…

Solar and Stellar Astrophysics · Physics 2013-12-19 Horst Balthasar , Christian Beck , Rohan E. Louis , Meetu Verma , Carsten Denker