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Related papers: On the origin of facular brightness

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We study the properties of waves in a facular region of moderate strength in the photosphere and chromosphere. Our aim is to analyse statistically the wave periods, power and phase relations as a function of the magnetic field strength and…

Solar and Stellar Astrophysics · Physics 2015-06-17 Roman Kostik , Elena Khomenko

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

Polar faculae are bright features that can be detected in solar limb observations and they are related to magnetic field concentrations. Although there is a large number of works studying them, some questions about their nature as their…

Solar and Stellar Astrophysics · Physics 2016-05-25 C. Quintero Noda , Y. Suematsu , B. Ruiz Cobo , T. Shimizu , A. Asensio Ramos

Magnetic bright points on the solar photosphere mark the footpoints of kilogauss magnetic flux tubes extending toward the corona. Convective buffeting of these tubes is believed to excite MHD waves, which can propagate to the corona and…

Solar and Stellar Astrophysics · Physics 2021-08-26 Samuel J. Van Kooten

Solar convection is visible as a net blueshift of absorption lines, which becomes apparent when observing quiet Sun granulation. This blueshift exhibits variations from the disc centre to the solar limb due to differing projection angles…

Solar and Stellar Astrophysics · Physics 2023-12-13 M. Ellwarth , B. Ehmann , S. Schäfer , A. Reiners

We aim to gain insight into the effect of network and faculae on solar irradiance from their apparent intensity. Taking full-disc observations from the Solar Dynamics Observatory, we examined the intensity contrast of network and faculae in…

Solar and Stellar Astrophysics · Physics 2021-02-19 K. L. Yeo , N. A. Krivova

We investigate the statistics of the intensity distributions as function of the wavelength for Ca II H and the CA II IR line at 854.2 nm to estimate the energy content. We derived the intensity variations at different heights of the solar…

Solar and Stellar Astrophysics · Physics 2013-03-14 C. Beck , R. Rezaei , K. G. Puschmann

Oscillation properties in two sunspots and two facular regions are studied using Solar Dynamics Observatory (SDO) data and ground-based observations in the SiI 10827 and HeI 10830 lines. The aim is to study different-frequency spatial…

Solar and Stellar Astrophysics · Physics 2014-11-25 N. I. Kobanov , D. Y. Kolobov , A. A. Chelpanov

Sunspots, faculae and the magnetic network contribute to solar irradiance variations. The contribution due to faculae and the network is of basic importance, but suffers from considerable uncertainty. We determine the contrasts of active…

Astrophysics · Physics 2009-11-07 A. Ortiz , S. K. Solanki , V. Domingo , M. Fligge , B. Sanahuja

Regular spaceborne measurements have revealed that solar brightness varies on multiple timescales, variations on timescales greater than a day being attributed to surface magnetic field. Independently, ground-based and spaceborne…

Solar and Stellar Astrophysics · Physics 2016-04-27 A. I. Shapiro , S. K. Solanki , N. A. Krivova , K. L. Yeo , W. K. Schmutz

This study aims at setting observational constraints on the continuum and line core intensity contrast of network and faculae, specifically, their relationship with magnetic field and disc position. Full-disc magnetograms and intensity…

Solar and Stellar Astrophysics · Physics 2014-07-17 K. L. Yeo , S. K. Solanki , N. A. Krivova

Light curves of solar-type stars often show gradual fluctuations due to rotational modulation by magnetic features (starspots and faculae) on stellar surfaces. Two quantitative measures of modulated light curves are employed as the proxies…

Solar and Stellar Astrophysics · Physics 2016-05-03 Han He , Huaning Wang , Duo Yun

Solar pores are strongly magnetized regions lacking a photospheric penumbra and characterized by predominantly vertical magnetic fields. We present a multi-line study of flashes in a solar pore using high-resolution observations from the…

Solar and Stellar Astrophysics · Physics 2026-02-11 Sandeep Dubey , Christian Beck , Rahul Yadav , Tobias Felipe , Shibu K Mathew

The bright regions in the solar chromosphere and temperature minimum have a good spatial correspondence with regions of intense photospheric magnetic field. Their observation started more than a hundred years ago with the invention of the…

Solar and Stellar Astrophysics · Physics 2022-08-10 Ismo Tähtinen , Ilpo Virtanen , Alexei A. Pevtsov , Kalevi Mursula

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

The Sun and stars with low magnetic activity levels, become photometrically brighter when their activity increases. Magnetically more active stars display the opposite behaviour and get fainter when their activity increases. We reproduce…

Solar and Stellar Astrophysics · Physics 2015-06-19 A. I. Shapiro , S. K. Solanki , N. A. Krivova , W. K. Schmutz , W. T. Ball , R. Knaack , E. V. Rozanov , Y. C. Unruh

We present properties of intensity oscillations of a sunspot in the photosphere and chromosphere using G~band and CaIIH filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequency reveal reduction of…

Solar and Stellar Astrophysics · Physics 2015-02-17 Ankala Raja Bayanna , Shibu K Mathew , Brajesh Kumar , Rohan E Louis , Parameswaran Venkatakrishnan

Magnetic features on the surface of stars, such as spots and faculae, cause stellar spectral variability on time-scales of days and longer. For stars other than the Sun, the spectral signatures of faculae are poorly understood, limiting our…

We investigate the relationship between the photospheric magnetic field of small-scale magnetic elements in the quiet Sun (QS) at disc centre, and the brightness at 214 nm, 300 nm, 313 nm, 388 nm, 397 nm, and at 525.02 nm. To this end we…

Solar and Stellar Astrophysics · Physics 2017-04-05 F. Kahil , T. L. Riethmüller , S. K. Solanki
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