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We studied the physical parameters of the penumbra in a large and fully-developed sunspot, one of the largest over the last two solar cycles, by using full-Stokes measurements taken at the photospheric Fe I 617.3 nm and chromospheric Ca II…

Solar and Stellar Astrophysics · Physics 2019-03-20 Mariarita Murabito , I. Ermolli , F. Giorgi , M. Stangalini , S. L. Guglielmino , S. Jafarzadeh , H. Socas-Navarro , P. Romano , F. Zuccarello

The Sun is replete with magnetic fields, with sunspots, pores and plage regions being their most prominent representatives on the solar surface. But even far away from these active regions, magnetic fields are ubiquitous. To a large extent,…

Solar and Stellar Astrophysics · Physics 2015-11-05 Andreas Lagg , Bruce Lites , Jack Harvey , Sanjay Gosain , Rebecca Centeno

Magnetic fields in the upper atmospheres of solar-like stars are believed to provide an enormous amount of energy to power the hot coronae and drive large-scale eruptions that could impact the habitability of planetary systems around these…

Plage regions are patches of concentrated magnetic field in the Sun's atmosphere where hot coronal loops are rooted. While previous studies have shed light on the properties of plage magnetic fields in the photosphere, there are still…

Solar and Stellar Astrophysics · Physics 2023-08-23 J. M. da Silva Santos , K. Reardon , G. Cauzzi , T. Schad , V. Martinez Pillet , A. Tritschler , F. Wöger , R. Hofmann , J. Stauffer , H. Uitenbroek

We gave an extensive study for the quasi-periodic perturbations on the time profiles of the line of sight (LOS) magnetic field in 10x10 sub-areas in a solar plage region (corresponds to a facula on the photosphere). The perturbations are…

Solar and Stellar Astrophysics · Physics 2022-04-20 Haisheng Ji , Parida Hashim , Zhenxiang Hong , Zhe Xu , Jinhua Shen , Kaifan Ji , Wenda Cao

The zero point of measured photospheric Doppler shifts is uncertain for at least two reasons: instrumental variations (from, e.g., thermal drifts), and the convective blueshift, a known correlation between intensity and upflows. Calibrated…

Solar and Stellar Astrophysics · Physics 2015-06-03 Brian T. Welsch , George H. Fisher , Xudong Sun

We investigate the magnetic field of a sunspot in the upper chromosphere and compare it to the field's photospheric properties. We observed the main leading sunspot of the active region NOAA 11124 on two days with the Tenrife Infrared…

Solar and Stellar Astrophysics · Physics 2017-08-23 Jayant Joshi , Andreas Lagg , Johann Hirzberger , Sami K. Solanki

In this paper, we study the properties of solar granulation in a facular region from the photosphere up to the lower chromosphere. Our aim is to investigate the dependence of granular structure on magnetic field strength. We use…

Solar and Stellar Astrophysics · Physics 2015-06-05 R. Kostik , E. Khomenko

We intend to investigate separately the photospheric and circumstellar (CS) magnetic field components in seven Herbig Ae stars. The study is based on low-resolution (R ~ 2000 and 4000) spectropolarimetric data collected from 2003 to 2005 at…

Astrophysics · Physics 2009-11-11 S. Hubrig , M. A. Pogodin , R. V. Yudin , M. Schoeller , R. S. Schnerr

The solar chromosphere is a transition layer between the cool, dense photosphere and the hot, rarefied corona. This boundary region plays a key role in regulating energy transport and structuring the magnetic field throughout the solar…

Solar and Stellar Astrophysics · Physics 2026-04-14 M. Kriginsky , J. Leenaarts , J. de la Cruz Rodriguez , S. Danilovic , O. Andriienko

Future solar missions and ground-based telescopes aim to understand the magnetism of the solar chromosphere. We performed a supporting study in Quintero Noda et al. (2016) focused on the infrared Ca II 8542 A line and we concluded that is…

Solar and Stellar Astrophysics · Physics 2016-12-07 C. Quintero Noda , T. Shimizu , Y. Katsukawa , J. de la Cruz Rodriguez , M. Carlsson , T. Anan , T. Oba , K. Ichimoto , Y. Suematsu

We determined the direction and strength of the photospheric and lower chromospheric magnetic field in the umbra and penumbra of a sunspot from inversions of spectropolarimetric observations of photospheric lines at 617\,nm and 1565\,nm,…

Solar and Stellar Astrophysics · Physics 2019-03-20 C. Beck , D. P. Choudhary

Abrupt and permanent changes of photospheric magnetic fields have been observed during solar flares. The changes seem to be linked to the reconfiguration of magnetic fields, but their origin is still unclear. We carried out a statistical…

Solar and Stellar Astrophysics · Physics 2018-01-17 J. S. Castellanos Durán , L. Kleint , B. Calvo-Mozo

Unipolar magnetic regions are often associated with supergranular cells. The chromosphere above these regions is regulated by the magnetic field, but the field structure is poorly known. In unipolar regions, the fibrillar arrangement does…

Solar and Stellar Astrophysics · Physics 2018-12-19 Carolina Robustini , Sara Esteban Pozuelo , Jorrit Leenaarts , Jaime de la Cruz Rodrìguez

The longitudinal asymmetry of the photospheric magnetic field distribution is studied on the basis of the data of the Kitt Peak National Solar Observatory (synoptic maps for the period 1976 - 2016). The method of vector summing of magnetic…

Solar and Stellar Astrophysics · Physics 2019-04-08 D. G. Baranov , E. S. Vernova , M. I. Tyasto , O. A. Danilova

Magnetic fields govern the plasma dynamics in the outer layers of the solar atmosphere, and electric fields acting on neutral atoms that move across the magnetic field enable us to study the dynamical coupling between neutrals and ions in…

Solar and Stellar Astrophysics · Physics 2015-06-18 Tetsu Anan , Roberto Casini , Kiyoshi Ichimoto

Photospheric magnetic fields are studied using synoptic maps from 1976 to 2003 produced at the National Solar Observatory, Kitt Peak (NSO/KP). Synoptic maps were averaged over the time interval of nearly three solar cycles (Solar Cycles…

Solar and Stellar Astrophysics · Physics 2016-04-08 E. S. Vernova , M. I. Tyasto , D. G. Baranov

The effect of using two representations of the normal-to-surface magnetic field to calculate photospheric measures that are related to active region (AR) potential for flaring is presented. Several AR properties were computed using…

Solar and Stellar Astrophysics · Physics 2018-01-24 Jordan A. Guerra , Sung-H. Park , Ioannis Kontogiannis , Peter T. Gallagher , Manolis Georgoulis , D. Shaun Bloomfield

We present the results obtained by analyzing high spatial and spectral resolution data of the solar photosphere acquired by the CRisp Imaging SpectroPolarimeter at the Swedish Solar Telescope on 6 August 2011, relevant to a large sunspot…

Spectropolarimetric data allow for simultaneous monitoring of stellar chromospheric $\log{R^{\prime}_{\rm{HK}}}$ activity and the surface-averaged longitudinal magnetic field, $B_l$, giving the opportunity to probe the relationship between…