English
Related papers

Related papers: Determining Absorption, Emissivity Reduction, and …

200 papers

Observations of the solar atmosphere show that internal gravity waves are generated by overshooting convection, but are suppressed at locations of magnetic flux, which is thought to be the result of mode conversion into magneto-acoustic…

Solar and Stellar Astrophysics · Physics 2017-02-01 G. Vigeesh , J. Jackiewicz , O. Steiner

The effect of temperature inhomogeneity on the periods, their ratios (fundamental vs. first overtone), and the damping times of the standing slow modes in gravitationally stratified solar coronal loops are studied. The effects of optically…

Solar and Stellar Astrophysics · Physics 2015-06-05 A. Abedini , H. Safari , S. Nasiri

As a continuation of the previous investigations of the symmetric and strongly non-symmetric ion-atom absorption processes in the far UV region within the models of the quiet Sun photosphere, these processes are studied here within a model…

Solar and Stellar Astrophysics · Physics 2015-06-19 Lj. M. Ignjatovic , A. A. Mihajlov , V. A. Sreckovic , M. S. Dimitrijevic

A sunspot is an ideal waveguide for a variety of magnetohydrodynamic waves, which carry a significant amount of energy to the upper atmosphere and could be used as a tool to probe magnetic and thermal structure of a sunspot. In this study,…

Solar and Stellar Astrophysics · Physics 2020-09-02 Song Feng , Zheng Deng , Ding Yuan , Zhi Xu , Xiao Yang

Discovered in 1909 the Evershed effect represents strong mass outflows in sunspot penumbra, where the magnetic field of sunspots is filamentary and almost horizontal. These flows play important role in sunspots and have been studied in…

Solar and Stellar Astrophysics · Physics 2009-08-03 Irina N. Kitiashvili , Alexander G. Kosovichev , Alan A. Wray , Nagi N. Mansour

We present the initial results of an observational study into the variation of the dominant length-scale of quiet solar emission: supergranulation. This length-scale reflects the radiative energy in the plasma of the upper solar…

Solar and Stellar Astrophysics · Physics 2015-05-27 Scott W. McIntosh , Robert J. Leamon , Rachel A. Hock , Mark P. Rast , Roger K. Ulrich

The photomolecular effect has been hypothesized to enhance evaporation of water at visible wavelengths. This study develops a measurement technique to investigate its presence and magnitude at the liquid-vapor interface of water. The…

Optics · Physics 2026-03-19 Preston Bohm , Mingjun Li , Akanksha K. Menon , Zhuomin M. Zhang

It has been shown that resonant absorption is a robust physical mechanism to explain the observed damping of magnetohydrodynamic (MHD) kink waves in the solar atmosphere due to naturally occurring plasma inhomogeneity in the direction…

Solar and Stellar Astrophysics · Physics 2015-05-28 Roberto Soler , Jaume Terradas , Gary Verth , Marcel Goossens

On modern satellite observations of the Sun in the continuum with high spatial resolution, as well as on high-quality ground observations, a large number of small dark areas can be observed. These regions have no penumbra, have a contrast…

Solar and Stellar Astrophysics · Physics 2022-06-08 Andrey G. Tlatov

Fast (>700 km/s) and slow (~400 km/s) winds stream from the Sun, permeate the heliosphere and influence the near-Earth environment. While the fast wind is known to emanate primarily from polar coronal holes, the source of the slow wind…

Solar and Stellar Astrophysics · Physics 2016-06-01 David H. Brooks , Ignacio Ugarte-Urra , Harry P. Warren

Umbral dots (UDs) are transient, bright features observed in the umbral region of a sunspot. We study the physical properties of UDs observed in sunspots of different sizes. The aim of our study is to relate the physical properties of…

Solar and Stellar Astrophysics · Physics 2018-03-14 Rahul Yadav , Rohan E. Louis , Shibu K. Mathew

The role of the acoustic continuum associated with compact sources in the Sun's interior wave field is explored for a simple polytropic model. The continuum produces a near-field acoustic structure -- the so-called `acoustic jacket' -- that…

Solar and Stellar Astrophysics · Physics 2015-06-15 Paul S. Cally

Aims: To study the heating of solar chromospheric magnetic and nonmagnetic regions by acoustic and magnetoacoustic waves, the deposited acoustic-energy flux derived from observations of strong chromospheric lines is compared with the total…

Solar and Stellar Astrophysics · Physics 2021-04-07 V. Abbasvand , M. Sobotka , M. Švanda , P. Heinzel , W. Liu , L. Mravcová

Infrared carbon stars without visible counterparts are generally known as extreme carbon stars. We have selected a subset of these stars with absorption features in the 10-13 $\mu$m range, which has been tentatively attributed to silicon…

Certain regions of the solar atmosphere are at sufficiently low temperatures to be only partially ionised. The lower chromosphere contains neutral atoms, the existence of which greatly increases the efficiency of the damping of waves due to…

Astrophysics · Physics 2009-11-11 J. E. leake , T. D. Arber , M. L. Khodachenko

Photon trapping is believed to be an important mechanism in super-Eddington accretion, which greatly reduces the radiative efficiency as photons are swallowed by the central black hole before they can escape from the accretion flow. This…

High Energy Astrophysical Phenomena · Physics 2023-08-17 Cheng-Liang Jiao

In a power spectrum of the Sun's acoustic waves, the p modes have distinctly skewed frequency profiles. Furthermore, the asymmetry is observed to have the opposite sign in power spectra made from line-of-sight velocity and continuum…

Solar and Stellar Astrophysics · Physics 2011-12-21 Bradley W. Hindman

An enhancement in high-frequency acoustic power is commonly observed in the solar photosphere and chromosphere surrounding magnetic active regions. We perform 3D linear forward wave modelling with a simple wavelet pulse acoustic source to…

Solar and Stellar Astrophysics · Physics 2015-06-23 Carlos Rijs , Hamed Moradi , Damien Przybylski , Paul S. Cally

We present a seismological method to probe the solar atmosphere above sunspot umbrae with three-minute oscillations. Our technique allows us to estimate both the vertical distance between atmospheric layers and the wave-propagation speed…

Solar and Stellar Astrophysics · Physics 2017-12-27 A. S. Deres , S. A. Anfinogentov

The analysis of the meridional displacement velocity of individual solar pores and sunspots has been performed. In the period May 2010\,-\,March 2025 of observations in the continuum of the \textit{Solar Dynamics Observatory/Helioseismic…

Solar and Stellar Astrophysics · Physics 2025-07-01 Andrey Tlatov , Kseniya Tlatova