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Related papers: On the origin of facular brightness

200 papers

The far ultraviolet (FUV) continuum flux is recognized as a very sensitive diag- nostic of the temperature structure of the Sun's lower chromosphere. Until now analysis of the available stellar FUV data has shown that solar-type stars must…

Solar and Stellar Astrophysics · Physics 2015-05-30 Jeffrey L. Linsky , Rachel Bushinsky , Tom Ayres , Juan Fontenla , Kevin France

The influence of the convective structure of the solar photosphere on the shifts of spectral lines of iron was studied. Line profiles in the visible and infrared spectrum were synthesized with the use of 2-D time-dependent hydrodynamic…

Solar and Stellar Astrophysics · Physics 2010-04-21 V. A. Sheminova , A. S. Gadun

Proving the magnetic configuration of solar spicules has hitherto been difficult due to the lack of spatial resolution and image stability during off-limb ground-based observations. We report spectropolarimetric observations of spicules…

Solar and Stellar Astrophysics · Physics 2015-04-21 D. Orozco Suarez , A. Asensio Ramos , J. Trujillo Bueno

Magnetic elements have an intensity contrast that depends on the type of region they are located in (e.g. quiet Sun, or active region plage). Observed values also depend on the spatial resolution of the data. Here we investigate the…

Solar and Stellar Astrophysics · Physics 2019-01-16 F. Kahil , T. L. Riethmüller , S. K. Solanki

In addition to the `facular' brightening of active regions, the quiet Sun also contains a small scale magnetic field with associated brightenings in continuum radiation. We measure this contribution of quiet regions to the Sun's brightness…

Solar and Stellar Astrophysics · Physics 2011-08-11 R. S. Schnerr , H. C. Spruit

This work focus on the first results on the identification and characterization of periodic plasma density fluctuations in the outer corona, observed in STEREO-A COR1 white-light image time series. A 2D reconstruction of the spatial…

Solar and Stellar Astrophysics · Physics 2015-06-15 D. Telloni , R. Ventura , P. Romano , D. Spadaro , E. Antonucci

Variability observed in photometric lightcurves of late-type stars (on timescales longer than a day) is a dominant noise source in exoplanet surveys and results predominantly from surface manifestations of stellar magnetic activity, namely…

Granular convective motions reach into the lower solar atmosphere, typically causing photospheric spectral lines to exhibit a differential line shift. This Doppler shift to shorter wavelength is commonly known as convective blueshift. We…

Solar and Stellar Astrophysics · Physics 2019-01-30 Franziska Stief , Johannes Löhner-Böttcher , Wolfgang Schmidt , Tilo Steinmetz , Ronald Holzwarth

The interaction of magnetic fields and convection is investigated in the context of the coronal heating problem. We study the motions of photospheric magnetic elements using filtergrams obtained at the Swedish Vacuum Solar Telescope at La…

In \citet{Stangalini20} and \citet{Deb20}, magnetic oscillations were detected in the chromosphere of a large sunspot and found to be linked to the coronal locations where a First Ionization Potential (FIP) effect was observed. In an…

We derive correlation coefficients between temperature and line-of-sight velocity as a function of optical depth throughout the solar photosphere for the non-magnetic photosphere and a small area of enhanced magnetic activity. The maximum…

Astrophysics · Physics 2017-12-27 J. Koza , A. Kucera , J. Rybák , H. Wöhl

The integrated brightness of the Sun shows variability on time-scales from minutes to decades. This variability is mainly caused by pressure mode oscillations, by granulation and by dark spots and bright faculae on the surface of the Sun.…

Solar and Stellar Astrophysics · Physics 2015-06-03 C. Karoff

The solar convection manifests as granulation and intergranulation at the solar surface. In the photosphere, convective motions induce differential Doppler shifts to spectral lines. The observed convective blueshift varies across the solar…

Solar and Stellar Astrophysics · Physics 2018-03-14 Johannes Löhner-Böttcher , Wolfgang Schmidt , Franziska Stief , Tilo Steinmetz , Ronald Holzwarth

Our aim is to determine the plasma properties of a coronal bright point and compare its magnetic topology extrapolated from magnetogram data with its appearance in X-ray images. We analyse spectroscopic data obtained with EIS/Hinode, Ca II…

Astrophysics · Physics 2008-10-07 D. Pérez-Suárez , R. C. Maclean , J. G. Doyle , M. S. Madjarska

How global faculae and network coverage relates to that of sunspots is relevant to the brightness variations of the Sun and Sun-like stars. We extend earlier studies that found the facular-to-sunspot-area ratio diminishes with total sunspot…

Solar and Stellar Astrophysics · Physics 2020-10-06 K. L. Yeo , S. K. Solanki , N. A. Krivova

Wave theories of heating the chromosphere, corona, and solar wind due to photospheric fluctuations are strengthened by the existence of observed wave coherency up to the transition region (TR). The coherency of solar spicules' intensity…

Solar and Stellar Astrophysics · Physics 2017-02-08 Alireza Ahangarzadeh Maralani , Ehsan Tavabi , Ali Ajabshirizadeh

Solar granulation consists of dynamic convective plasma cells that rise from the solar interior to the surface. The interaction between these plasma cells and the Sun's magnetic field provides valuable insights into plasma dynamics near the…

Solar and Stellar Astrophysics · Physics 2026-04-01 J. I. Campos Rozo , J. Jurčák , S. M. Díaz Castillo , M. van Noort

Rotational periods derived from autocorrelation (ACF) techniques on stars photometrically similar to the Sun in Kepler data have proven difficult to reliably determine. We investigate various instrumental and astrophysical factors affecting…

Solar and Stellar Astrophysics · Physics 2024-01-25 Canis Li , Gibor Basri

Advances in solar instrumentation have led to a widespread usage of time series to study the dynamics of solar features, specially at small spatial scales and at very fast cadences. Physical processes at such scales are determinant as…

Solar and Stellar Astrophysics · Physics 2015-06-19 S. Vargas Dominguez , J. Palacios , L. Balmaceda , I. Cabello , V. Domingo

Vortex-type motions have been measured by tracking bright points in high-resolution observations of the solar photosphere. These small-scale motions are thought to be determinant in the evolution of magnetic footpoints and their interaction…

Solar and Stellar Astrophysics · Physics 2015-05-18 L. Balmaceda , S. Vargas Domínguez , J. Palacios , I. Cabello , V. Domingo