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Velocity oscillations in sunspot umbrae have been measured simultaneously in two spectral lines: the photospheric Silicon I 10827 A line and the chromospheric Helium I 10830 A multiplet. From the full Stokes inversion of temporal series of…

Astrophysics · Physics 2009-11-13 Rebecca Centeno , Manuel Collados , Javier Trujillo Bueno

We have analyzed H-alpha intensity images obtained at a 1 minute cadence with the Global Oscillation Network Group (GONG) system to investigate the properties of oscillations in the 0-8 mHz frequency band at the location and time of strong…

Solar and Stellar Astrophysics · Physics 2018-03-08 Teresa Monsue , Frank Hill , Keivan G. Stassun

The observed splittings of solar oscillation frequencies can be employed to separate the effects of internal solar rotation and to estimate the contribution from a large-scale magnetic field or any latitude-dependent thermal perturbation…

Astrophysics · Physics 2007-05-23 H. M. Antia , S. M. Chitre , M. J. Thompson

3-minute oscillations in the chromosphere are attributed to both slow magnetoacoustic waves propagating from the photosphere, and to oscillations generated within the chromosphere itself at its natural frequency as a response to a…

Solar and Stellar Astrophysics · Physics 2020-11-23 Laurel Farris , R. T. James McAteer

Magnetoseismology, a technique of magnetic field diagnostics based on observations of magnetohydrodynamic (MHD) waves, has been widely used to estimate the field strengths of oscillating structures in the solar corona. However, previously…

Solar and Stellar Astrophysics · Physics 2020-11-05 Zihao Yang , Hui Tian , Steven Tomczyk , Richard Morton , Xianyong Bai , Tanmoy Samanta , Yajie Chen

Solar-like oscillations are stochastically excited by turbulent convection. In this work we investigate changes in the acoustic oscillation power spectrum of solar-type stars by varying the treatment of convection in the equilibrium…

Astrophysics · Physics 2007-05-23 Reza Samadi , Guenter Houdek , Marie-Jo Goupil , Yveline Lebreton , Annie Baglin

It has long been known that magnetic plage and sunspots are regions in which the power of acoustic waves is reduced within the photospheric layers. Recent observations now suggest that this suppression of power extends into the low…

Solar and Stellar Astrophysics · Physics 2015-06-19 Rekha Jain , Andrew Gascoyne , Bradley W. Hindman , Benjamin Greer

We have studied the angular distribution of the magnetic field vector in the solar internetwork employing high-quality data (noise level $\sigma \approx 3\times 10^{-4}$ in units of the quiet-Sun intensity) at different latitudes recorded…

Solar and Stellar Astrophysics · Physics 2015-06-12 J. M. Borrero , P. Kobel

Rapidly decaying slow magnetoacoustic waves are regularly observed in the solar coronal structures, offering a promising tool for a seismological diagnostics of the coronal plasma, including its thermodynamical properties. The effect of…

Solar and Stellar Astrophysics · Physics 2019-08-21 D. Y. Kolotkov , V. M. Nakariakov , D. I. Zavershinskii

The velocity field in the lower solar atmosphere undergoes strong interactions with magnetic fields. Many authors have pointed out that power is reduced by a factor between two and three within magnetic regions, depending on frequency,…

Solar and Stellar Astrophysics · Physics 2015-06-12 F. Giannattasio , M. Stangalini , D. Del Moro , F. Berrilli

Some observations suggest that solar spicules show small amplitude and high frequency oscillations of magneto-acoustic waves, which arise from photospheric granular forcing. We apply the method of MHD seismology to determine the period of…

Astrophysics · Physics 2009-11-13 A. Ajabshirizadeh , E. Tavabi , S. Koutchmy

Recently, the availability of new high-spatial and -temporal resolution observations of the solar photosphere has allowed the study of the oscillations in small magnetic elements. Small magnetic elements have been found to host a rich…

Solar and Stellar Astrophysics · Physics 2015-06-17 M. Stangalini , F. Berrilli , G. Consolini

By analyzing numerically simulated solar oscillation data, we study the influence of non-uniform distribution of acoustic wave amplitude, acoustic source strength, and perturbations of the sound speed on the shifts of acoustic travel times…

Astrophysics · Physics 2009-11-13 Konstantin V. Parchevsky , Junwei Zhao , Alexander G. Kosovichev

Recent analysis of the helioseismic observations indicate that the previously observed surface torsional oscillations extend significantly downwards into the solar convection zone. In an attempt to understand these oscillations, we study…

Astrophysics · Physics 2007-05-23 Eurico Covas , Reza Tavakol , David Moss , Andrew Tworkowski

It is well known that the dominant frequency of oscillations in the solar photosphere is $\approx$3 mHz, which is the result of global resonant modes pertaining to the whole stellar structure. However, analyses of the horizontal motions of…

Solar and Stellar Astrophysics · Physics 2024-07-08 M. Berretti , M. Stangalini , G. Verth , S. Jafarzadeh , D. B. Jess , F. Berrilli , S. D. T. Grant , T. Duckenfield , V. Fedun

Understanding the characteristics of the solar magnetic field is essential for interpreting solar activities and dynamo. In this research, we investigated the asymmetric distribution of the solar photospheric magnetic field values, using…

Solar and Stellar Astrophysics · Physics 2021-10-04 Jing-Chen Xu , Ke-Jun Li , Peng-Xin Gao

We present high-cadence observations and simulations of the solar photosphere, obtained using the Rapid Oscillations in the Solar Atmosphere imaging system and the MuRAM magneto-hydrodynamic code, respectively. Each dataset demonstrates a…

Solar and Stellar Astrophysics · Physics 2015-06-03 D. B. Jess , S. Shelyag , M. Mathioudakis , P. H. Keys , D. J. Christian , F. P. Keenan

We study the properties of slow magneto-acoustic waves that are naturally excited due to turbulent convection and investigate their role in the energy balance of a plage region using three dimensional (3D) radiation-MHD simulations. We…

Solar and Stellar Astrophysics · Physics 2021-08-11 Nitin Yadav , Robert H. Cameron , Sami K. Solanki

We studied the low-frequency $\lesssim 0.5\;$h$^{-1}$ (long-period $\gtrsim 2\;$h) oscillations of active regions (ARs). The investigation is based on an analysis of a time series built from Solar Dynamics Observatory/Helioseismic and…

Solar and Stellar Astrophysics · Physics 2022-03-22 G. Dumbadze , B. M. Shergelashvili , S. Poedts , T. V. Zaqarashvili , M. Khodachenko , P. De Causmaecker

We investigate the parameters of global solar p-mode oscillations, namely damping width $\Gamma$, amplitude $A$, mean squared velocity $\langle v^2\rangle$, energy $E$, and energy supply rate $\mathrm{d}E/\mathrm{d} t$, derived from two…

Solar and Stellar Astrophysics · Physics 2018-10-23 René Kiefer , Rudi Komm , Frank Hill , Anne-Marie Broomhall , Markus Roth