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Numerous magnetohydrodynamic oscillations have been reported within solar pores over the past decades, including in line-of-sight (LOS) velocities, intensities, and magnetic field strengths. Our aim is to identify whether high-amplitude…

Solar and Stellar Astrophysics · Physics 2021-10-13 C. J. Nelson , R. J. Campbell , M. Mathioudakis

The O I 135.6 nm spectral line is formed in the chromosphere at the same heights as the Mg II h&k line cores are formed. As the O I line is optically thin, it represents a possibility for measuring the non-thermal velocities in this region…

Solar and Stellar Astrophysics · Physics 2026-05-05 Viggo Hansteen , Mats Carlsson , Bart De Pontieu , Daniel Nóbrega-Siverio

We investigate the fine structure of magnetic fields in the atmosphere of the quiet Sun. We use photospheric magnetic field measurements from {\sc Sunrise}/IMaX with unprecedented spatial resolution to extrapolate the photospheric magnetic…

We study chromospheric oscillations including umbral flashes and running penumbral waves in a sunspot of active region (AR) using scanning spectroscopy in H-alpha and Ca II 8542A, with the Fast Imaging Solar Spectrograph (FISS) at the 1.6…

Solar and Stellar Astrophysics · Physics 2013-02-07 Ram Ajor Maurya , Jongchul Chae , Hyungmin Park , Heesu Yang , Donguk Song , Kyuhyoun Cho

We describe the characteristics and evolution of the magnetic field and chromospheric emission in an active region core observed by the Solar Optical Telescope on Hinode. Consistent with previous studies, we find that the moss is unipolar,…

Solar and Stellar Astrophysics · Physics 2015-05-19 David H. Brooks , Harry P. Warren , Amy R. Winebarger

We simultaneously observed the Stokes parameters of the photospheric iron line pair at 630.2 nm and the intensity profile of the chromospheric Ca II H line at 396.8 nm in a quiet Sun region at a heliocentric angle of 53 deg. We perform a…

Astrophysics · Physics 2008-11-26 R. Rezaei , R. Schlichenmaier , C. A. R. Beck , J. H. M. J. Bruls , W. Schmidt

The structure of the photospheric magnetic field during solar flares is examined using echelle spectropolarimetric observations. The study is based on several Fe I and Cr I lines observed at locations corresponding to brightest H$\alpha$…

Solar and Stellar Astrophysics · Physics 2015-06-19 Mykola Gordovskyy , Vsevolod G. Lozitsky

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

In this study we present simultaneous low-resolution longitudinal magnetic field measurements and high-resolution spectroscopic observations of the cool single giant FK Com. The variation of the magnetic field over the rotational period of…

We investigate the ratio of the vertical and horizontal velocities of the photospheric plasma flows in the region of emerging magnetic fields on the Sun. We carried out a study of photospheric velocities during the first hours of the…

Solar and Stellar Astrophysics · Physics 2012-12-17 A. Khlystova

The aim of this study is to explore the suitability of chromospheric images for magnetic modeling of active regions. We use high-resolution images (0.1") from the Interferometric Bidimensional Spectrometer (IBIS) in the Ca II 8542 A line,…

Solar and Stellar Astrophysics · Physics 2016-07-25 M. J. Aschwanden , K. Reardon , D. Jess

We study structure and dynamics of the turbulent photospheric magnetic field in the active region NOAA 11158 by characterizing the spatial and temporal scaling properties of the line-of-sight (LOS) component. Using high-resolution…

Solar and Stellar Astrophysics · Physics 2015-06-18 Jordan A. Guerra , Antti A. Pulkkinen , Vadim M. Uritsky , Seiji Yashiro

Velocity oscillations "measured" simultaneously at the photosphere and the chromosphere -from time series of spectropolarimetric data in the 10830 A region- of different solar magnetic features allow us to study the properties of wave…

Astrophysics · Physics 2011-02-11 Rebecca Centeno , Manuel Collados , Javier Trujillo Bueno

Large-scale velocity fields in the solar photosphere remain a mystery in spite of many years of intensive studies. In this thesis, the new method of the measurements of the solar photospheric flow fields is proposed. It is based on local…

Astrophysics · Physics 2007-12-13 Michal Svanda

The line-of-sight (LOS) component of the large-scale photospheric magnetic field has been observed since the 1950s, but the daily full-disk observations of the full vector magnetic field started only in 2010 using the SOLIS Vector Stokes…

Space Physics · Physics 2019-04-25 Ilpo I. Virtanen , Alexei A. Pevtsov , Kalevi Mursula

We analyzed the full Stokes spectra using simultaneous measurements of the photospheric (FeI 630.15 and 630.25 nm) and chromospheric (MgI b2 517.27 nm) lines. The data were obtained with the HAO/NSO Advanced Stokes Polarimeter, about a near…

Solar and Stellar Astrophysics · Physics 2015-05-19 Na Deng , Debi Prasad Choudhary , K. S. Balasubramaniam

Correlation analysis is obtained among Faraday rotation measure, HI column density, thermal and synchrotron radio brightness using archival all-sky maps of the Galaxy. A method is presented to calculate the magnetic strength and its…

Astrophysics of Galaxies · Physics 2019-08-29 Y. Sofue , H. Nakanishi , K. Ichiki

Periodic oscillations at 338 nHz in the Earth frame are observed at high latitudes in direct Doppler velocity measurements. These oscillations correspond to the $m=1$ high-latitude global mode of inertial oscillation. In this study, we…

Solar and Stellar Astrophysics · Physics 2025-11-12 Stephan G. Heinemann , Zhi-Chao Liang , Laurent Gizon

We present results of the study of chromospheric and photospheric line-of-sight velocity fields in the young active region NOAA 11024. Multi-layer, multi-wavelength observational data were used for the analysis of the emerging flux in this…

Solar and Stellar Astrophysics · Physics 2012-12-07 N. N. Kondrashova , M. N. Pasechnik , S. N. Chornogor , E. V. Khomenko

We reassess the relationship between the photospheric magnetic field strength and the Ca II K intensity for a variety of surface features as a function of the position on the disc and the solar activity level. This relationship can be used…

Solar and Stellar Astrophysics · Physics 2019-06-26 Theodosios Chatzistergos , Ilaria Ermolli , Sami K. Solanki , Natalie A. Krivova , Fabrizio Giorgi , Kok Leng Yeo