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Related papers: Bright fibrils in Ca II K

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Broad-band images of the solar chromosphere in the Ca II H&K line cores around active regions are covered with fine bright elongated structures called bright fibrils. The mechanisms that form these structures and cause them to appear bright…

Solar and Stellar Astrophysics · Physics 2020-05-06 Sepideh Kianfar , Jorrit Leenaarts , Sanja Danilovic , Jaime de la Cruz Rodríguez , Carlos José Díaz Baso

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

Fibrils in the solar chromosphere carry transverse oscillations as determined from non-spectroscopic imaging data. They are estimated to carry an energy flux of several $\mathrm{kW~m}^{-2}$, which is a significant fraction of the average…

(Abridged) Aims: In this paper, we seek to establish the suitability of imaging spectroscopy performed in the Ca II 854.2 nm line as a means to investigate the solar chromosphere at high resolution. Methods: We utilize monochromatic images…

Fibrils are dynamic plasma structures in the solar chromosphere. Studying these structures is critical for understanding solar atmospheric heating and mass transportation. The purpose of this study is to obtain the characteristics of…

Solar and Stellar Astrophysics · Physics 2025-09-24 Qifan Dong , Xiaoli Yan , Zhike Xue , Jincheng Wang , Zhe Xu , Liheng Yang , Yian Zhou , Xinsheng Zhang , Zongyin Wu , Guotang Wu

A dense forest of slender bright fibrils near a small solar active region is seen in high-quality narrowband Ca II H images from the SuFI instrument onboard the Sunrise balloon-borne solar observatory. The orientation of these slender Ca II…

Context. Chromospheric fibrils are thin and elongated structures that connect nearby photospheric magnetic field concentrations of opposite polarities. Aims. We assess the possibilities and drawbacks related to the use of current…

Solar and Stellar Astrophysics · Physics 2023-04-05 M. Kriginsky , R. Oliver , D. Kuridze

Aim: To study the interaction of the solar chromosphere with the transition region, in particular active-region jets in the transition region and their relation to chromospheric fibrils. Methods: We carefully align image sequences taken…

Astrophysics · Physics 2008-11-26 A. G. de Wijn , B. De Pontieu

Fibrillar structures are ubiquitous in the solar chromosphere and their potential for mediating the mass and energy transport in the solar atmosphere is undeniable. An accurate determination of their properties requires the use of advanced…

Solar and Stellar Astrophysics · Physics 2024-11-11 Matheus Kriginsky , Ramon Oliver

Sunspot chromospheres display vigorous oscillatory signature when observed in chromospheric diagnostics like the strong Ca II lines and H-alpha. New high-resolution sunspot observations from the Swedish 1-m Solar Telescope show the…

Solar and Stellar Astrophysics · Physics 2015-06-16 Luc Rouppe van der Voort , Jaime de la Cruz Rodriguez

We use seeing-free high spatial resolution Ca II H data obtained by the SUNRISE observatory to determine properties of slender fibrils in the lower solar chromosphere. In this work we use intensity images taken with the SUFI instrument in…

We present unprecedented high resolution H-alpha observations, obtained with the Swedish 1-m Solar Telescope, that, for the first time, spatially and temporally resolve dynamic fibrils in active regions on the Sun. These jet-like features…

Astrophysics · Physics 2008-11-26 B. De Pontieu , V. H. Hansteen , L. Rouppe van der Voort , M. van Noort , M. Carlsson

Aims. To understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable…

Solar and Stellar Astrophysics · Physics 2015-02-11 V. M. J. Henriques , E. Scullion , M. Mathioudakis , D. Kiselman , P. T. Gallagher , F. P. Keenan

We recently reported extremely rapid changes in chromospheric fine structure observed using the IBIS instrument in the red wing of H alpha. Here, we examine data obtained during the same observing run (August 7 2010), of a mature active…

Solar and Stellar Astrophysics · Physics 2015-06-18 Isabel Lipartito , Philip Judge , Kevin Reardon , Gianna Cauzzi

Solar spicules are chromospheric fibrils that appear everywhere on the Sun, yet their origin is not understood. Using high resolution observations of spicules obtained with the Swedish 1-m Solar Telescope, we aim to understand how spicules…

Solar and Stellar Astrophysics · Physics 2016-06-22 Tiago M. D. Pereira , Luc Rouppe van der Voort , Mats Carlsson

We report on our observing program to capture simultaneous spectra of Ca II and Balmer lines in a sample of nearby M3 dwarfs. Our goal is to investigate the chromospheric temperature structure required to produce these lines at the observed…

Astrophysics · Physics 2009-11-13 Lucianne M. Walkowicz , Suzanne L. Hawley

Solar chromospheric fibrils, as observed in the core of strong chromospheric spectral lines, extend from photospheric field concentrations suggesting that they trace magnetic field lines. These images have been historically used as proxies…

Solar and Stellar Astrophysics · Physics 2017-03-15 A. Asensio Ramos , J. de la Cruz Rodriguez , M. J. Martinez Gonzalez , H. Socas-Navarro

Fibrils are thin elongated features visible in the solar chromosphere in and around magnetized regions. Because of their visual appearance, they have been traditionally considered a tracer of the magnetic field lines. For the first time, we…

Solar and Stellar Astrophysics · Physics 2015-05-27 J. de la Cruz Rodríguez , H. Socas-Navarro

We characterize, for the first time, type-II spicules in Ca II K 3934\AA\ using the CHROMIS instrument at the Swedish 1-m Solar Telescope. We find that their line formation is dominated by opacity shifts with the K$_{3}$ minimum best…

Solar and Stellar Astrophysics · Physics 2020-05-06 Souvik Bose , Vasco M. J. Henriques , Jayant Joshi , Luc Rouppe van der Voort

The fine structures of the solar chromosphere, driven by photospheric motions, play a crucial role in the dynamics of solar magnetic fields. Many have been already identified such as fibrils, filament feet, and arch filament systems. Still,…

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