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Low-frequency longitudinal oscillations of a flaring coronal loop are studied numerically. In the recent work of Nakariakov et al., Astron. and Astrophys., 414, L25-L28 (2004) it has been shown that the time dependences of density and…

Astrophysics · Physics 2009-11-10 D. Tsiklauri , V. M. Nakariakov , T. D. Arber , M. J. Aschwanden

The analysis of quickly damped transverse oscillations of solar coronal loops using magneto-hydrodynamic seismology allow us to infer physical parameters that are difficult to measure otherwise. Under the assumption that such damped…

Solar and Stellar Astrophysics · Physics 2015-06-15 A. Asensio Ramos , I. Arregui

Coronal oscillations offer insight into energy transport and driving in the solar atmosphere. Knowing its polarisation state helps constrain a wave's displacement and velocity amplitude, improving estimates of wave energy flux and…

Solar and Stellar Astrophysics · Physics 2025-03-10 T. J. Duckenfield , D. B. Jess , R. J. Morton , S. Jafarzadeh

Observations of transversal coronal loop oscillations very often show the excitation and damping of oscillations in groups of coronal loops rather than in individual and isolated structures. We present results on the oscillatory properties…

Astrophysics · Physics 2009-11-13 Inigo Arregui , Jaume Terradas , Ramon Oliver , Jose Luis Ballester

The standing slow magneto-acoustic oscillations in cooling coronal loops are investigated. There are two damping mechanisms which are considered to generate the standing acoustic modes in coronal magnetic loops namely thermal conduction and…

Solar and Stellar Astrophysics · Physics 2015-01-13 Khalil Salim Al-Ghafri

We investigate the effect of a variable, i.e. time-dependent, background on the standing acoustic (i.e. longitudinal) modes generated in a hot coronal loop. A theoretical model of 1D geometry describing the coronal loop is applied. The…

Solar and Stellar Astrophysics · Physics 2012-04-02 K. S. Al-Ghafri , R. Erdélyi

Context. One of the typical features shown by observations of solar prominence oscillations is that they are damped in time and that the values of the damping times are usually between one and three times the corresponding oscillatory…

Astrophysics · Physics 2009-11-13 R. Soler , R. Oliver , J. L. Ballester

Quasi-periodic propagating disturbances in coronal structures have been interpreted as slow magneto-acoustic waves and/or periodic upflows. Here we aim to understand their nature from the observed properties using a three-hour imaging…

Solar and Stellar Astrophysics · Physics 2015-06-11 S. Krishna Prasad , D. Banerjee , T. Van Doorsselaere , J. Singh

Fast sausage modes in solar magnetic coronal loops are only fully contained in unrealistically short dense loops. Otherwise they are leaky, losing energy to their surrounds as outgoing waves. This causes any oscillation to decay…

Solar and Stellar Astrophysics · Physics 2017-11-02 Paul S. Cally , Ming Xiong

This short review paper gives an overview of recently observed transverse, propagating velocity perturbations in coronal loops. These ubiquitous perturbations are observed to undergo strong damping as they propagate. Using 3D numerical…

Solar and Stellar Astrophysics · Physics 2015-10-06 I. De Moortel , D. J. Pascoe , A. N. Wright , A. W. Hood

Using the ULTRASPEC instrument mounted on the 2.4-m Thai National Telescope, we observed two large flares, each with a total energy close to 10^34 erg with sub-second cadence. A combination of a wavelet analysis, a Fourier transform plus an…

Slow magnetoacoustic oscillations in stellar coronal loops with gravitational stratification are analyzed with a numerical solution of the boundary-value problem for eigenvalues and eigen functions. In this study, we only focus on the…

Solar and Stellar Astrophysics · Physics 2022-06-01 Daye Lim , Valery M. Nakariakov , Yong-Jae Moon

A model interpreting variations of EUV brightness upward propagating in solar coronal loops as slow magnetoacoustic waves is developed. A loop is considered to have a non-zero plane inclination angle and offset of circular loop centre from…

Astrophysics · Physics 2009-11-07 D. Tsiklauri , V. M. Nakariakov

Being directly observed in the Doppler shift and imaging data and indirectly as quasi-periodic pulsations in solar and stellar flares, slow magnetoacoustic waves offer an important seismological tool for probing many vital parameters of the…

Solar and Stellar Astrophysics · Physics 2022-05-25 Dmitrii Y. Kolotkov , Valery M. Nakariakov

The ubiquity of recently discovered low-amplitude decayless kink oscillations of plasma loops allows for the seismological probing of the corona on a regular basis. In particular, in contrast to traditionally applied seismology which is…

Solar and Stellar Astrophysics · Physics 2019-11-06 Sergey A. Anfinogentov , Valery. M. Nakariakov

We study the effects of time delayed linear and nonlinear feedbacks on the dynamics of a single Hopf bifurcation oscillator. Our numerical and analytic investigations reveal a host of complex temporal phenomena such as phase slips,…

chao-dyn · Physics 2009-10-31 D. V. Ramana Reddy , A. Sen , G. L. Johnston

Identifying the underlying mechanisms behind the excitation of transverse oscillations in coronal loops is essential for their role as diagnostic tools in coronal seismology and their potential use as wave heating mechanisms of the solar…

Solar and Stellar Astrophysics · Physics 2021-02-17 Konstantinos Karampelas , Tom Van Doorsselaere

We aim to study the standing fundamental kink mode of coronal loops in the nonlinear regime, investigating the changes in energy evolution in the cross-section and oscillation amplitude of the loop which are related to nonlinear effects, in…

Solar and Stellar Astrophysics · Physics 2016-11-02 N. Magyar , T. Van Doorsselaere

Oscillations of coronal loops in the Sun have been reported in both imaging and spectral observations at the onset of flares. Images reveal transverse oscillations, whereas spectra detect line-of-sight velocity or Doppler-shift…

Solar and Stellar Astrophysics · Physics 2015-05-27 Danica Tothova , Davina Innes , Guillermo Stenborg

Context: As a ubiquitous phenomenon, large-amplitude longitudinal filament oscillations usually decay in 1--4 periods. Recently, we observed a decayless case of such oscillations in the corona. Aims: We try to understand the physical…

Solar and Stellar Astrophysics · Physics 2022-07-13 Y. W. Ni , J. H. Guo , Q. M. Zhang , J. L. Chen , C. Fang , P. F. Chen