English
Related papers

Related papers: Observations, analysis and interpretation with non…

200 papers

Classic solar models put the Chromosphere-Corona Transition Region (CCTR} at $\sim2$Mm above the $\tau_{5000} = 1$ level, whereas rMHD models place it in a wider range of heights. Observational verification is scarce. We review and discuss…

Solar and Stellar Astrophysics · Physics 2022-07-08 C. E. Alissandrakis

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

Small-scale magnetic flux concentrations contribute significantly to the brightness variations of the Sun, yet observing them - particularly their magnetic field - near the solar limb remains challenging. Solar Orbiter offers an…

Solar and Stellar Astrophysics · Physics 2026-02-11 K. Albert , J. Hirzberger , N. A. Krivova , X. Li , D. Calchetti , G. Valori , J. Sinjan , S. K. Solanki , A. Gandorfer , J. Woch , D. Orozco Suárez , S. Parenti

Observations of the emission at radio, millimeter, sub-millimeter, and infrared wavelengths in the center of the solar disk validate the auto-consistence of semi-empirical models of the chromosphere. Theoretically, these models must…

Solar and Stellar Astrophysics · Physics 2016-07-20 Victor De la Luz

We examined the structure near the solar limb in TRACE images of the continuum and in the 1600 and 171 A bands as well as in SDO images in the continuum (from HMI) and all AIA bands. The images in different wavelength bands were carefully…

Solar and Stellar Astrophysics · Physics 2019-07-31 C. E. Alissandrakis , A. Valentino

Spicules are ubiquitous, fast moving jets observed off-limb in chromospheric spectral lines. Combining the recently-launched Interface Region Imaging Spectrograph with the Solar Dynamics Observatory and Hinode, we have a unique opportunity…

Solar and Stellar Astrophysics · Physics 2015-05-12 H. Skogsrud , L. Rouppe van der Voort , B. De Pontieu , T. M. D. Pereira

Flare ribbons are bright manifestations of flare energy dissipation in the lower solar atmosphere. For the first time, we report on high-resolution imaging spectroscopy observations of flare ribbons situated off-limb in the H$\beta$ and Ca…

Solar and Stellar Astrophysics · Physics 2020-07-01 D. Kuridze , M. Mathioudakis , P. Heinzel , J. Koza , H. Morgan , R. Oliver , A. F. Kowalski , J. C. Allred

In the present work, we investigate the formation of Stokes profiles and spectro-polarimetric diagnostics in an active region plage near the limb. We use 3-D radiation-MHD simulations with unipolar fields of an average strength of 400 G,…

Solar and Stellar Astrophysics · Physics 2014-11-20 L. Yelles Chaouche , S. K. Solanki , L. Rouppe van der Voort , M. van Noort

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

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

Numerical simulations of the solar chromosphere have progressed towards reproducing spicules, which are transient features observed at the solar limb using spectral lines such as H$\alpha$, Ca II H&K, or Mg II h&k. Two types of spicules,…

Solar and Stellar Astrophysics · Physics 2026-02-04 Sanghita Chandra , Robert Cameron , Damien Przybylski , Sami K. Solanki

We present observations of the solar chromosphere obtained simultaneously with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph (IRIS). The observatories targeted a chromospheric plage…

Spicules are intermittently rising above the surface of the Sun eruptions; EUV jets are now also reported in immediately above layers. The variation of spicule orientation with respect to the solar latitude, presumably reflecting the…

Solar and Stellar Astrophysics · Physics 2021-07-27 E. Tavabi , S. Koutchmy

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

We investigated the off-limb spicules observed in the Mg II h and k lines by IRIS in a solar polar coronal hole. We analyzed the large dataset of obtained spectra to extract quantitative information about the line intensities, shifts, and…

Solar and Stellar Astrophysics · Physics 2020-01-15 Akiko Tei , Stanislav Gunar , Petr Heinzel , Takenori J. Okamoto , Jiri Stepan , Sonja Jejcic , Kazunari Shibata

We study a solar spicule observed off-limb using high-resolution imaging spectroscopy in the Ca II 8542 \AA\ line obtained with the CRisp Imaging SpectroPolarimeter (CRISP) on the Swedish 1-m Solar Telescope. Using a new version of the…

Solar and Stellar Astrophysics · Physics 2021-03-03 D. Kuridze , H. Socas-Navarro , J. Koza , R. Oliver

Using radiative magneto-hydrodynamic simulations of the magnetised solar photosphere and detailed spectro-polarimetric diagnostics with the FeI $6301.5\mathrm{\AA}$ and $6302.5\mathrm{\AA}$ photospheric lines in the local thermodynamic…

Solar and Stellar Astrophysics · Physics 2015-06-23 S. Shelyag

We study off-limb emission of the lower solar atmosphere using high-resolution imaging spectroscopy in the H$\beta$ and Ca II 8542 \r{A} lines obtained with the CHROMospheric Imaging Spectrometer (CHROMIS) and the CRisp Imaging…

Solar and Stellar Astrophysics · Physics 2022-10-05 D. Kuridze , P. Heinzel , J. Koza , R. Oliver

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