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Related papers: Solar H-alpha Oscillations from Intensity and Dopp…

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We study the acoustic properties of the solar chromosphere in the high-frequency regime using a time sequence of velocity measurements in the chromospheric Ca II 854.2 nm line taken with the Interferometric Bidimensional Spectrometer…

Astrophysics · Physics 2010-11-11 K. P. Reardon , F. Lepreti , V. Carbone , A. Vecchio

The subject of this study is oscillations in the lower atmosphere in coronal-hole regions, where the conditions are favorable for propagation between the atmospheric layers. Based on spectroscopic observations in photospheric and…

Solar and Stellar Astrophysics · Physics 2021-12-22 Andrei Chelpanov , Nikolai Kobanov , Maksim Chelpanov , Aleksandr Kiselev

We have developed the first self-consistent model for the observed large-amplitude oscillations along filament axes that explains the restoring force and damping mechanism. We have investigated the oscillations of multiple threads formed in…

Solar and Stellar Astrophysics · Physics 2012-04-06 Manuel Luna , Judith Karpen

The propagation of radio frequency (RF) waves in tokamaks can be affected by filamentary structures present in the edge plasma. The waves are reflected, refracted, and diffracted, leading to a decrease in efficiency of heating and/or…

Plasma Physics · Physics 2021-12-22 Spyridon I. Valvis , Abhay K. Ram , Kyriakos Hizanidis

Waves and oscillations are important solar phenomena, not only because they can propagate and dissipate energy in the chromosphere, but also because they carry information about the structure of the atmosphere in which they propagate. The…

Solar and Stellar Astrophysics · Physics 2022-01-26 Yi Chai , Dale E. Gary , Kevin P. Reardon , Vasyl Yurchyshyn

We use high spatial and temporal resolution observations from the Swedish Solar Telescope to study the chromospheric velocities of a C-class flare originating from active region NOAA 10969. A time-distance analysis is employed to estimate…

Solar and Stellar Astrophysics · Physics 2015-05-27 Peter H. Keys , David B. Jess , Mihalis Mathioudakis , Francis P. Keenan

Time series of photospheric magnetic parameters of solar active regions (ARs) are used to answer whether scaling properties of fluctuations embedded in such time series help to distinguish between flare-quiet and flaring ARs. We examine a…

Solar and Stellar Astrophysics · Physics 2020-10-21 Eo-Jin Lee , Sung-Hong Park , Yong-Jae Moon

The review addresses the spatial frequency morphology of sources of sunspot oscillations and waves, including their localization, size, oscillation periods, height localization with the mechanism of cut-off frequency that forms the observed…

Solar and Stellar Astrophysics · Physics 2016-03-09 Robert Sych

Standing slow mode waves in hot flaring loops are exclusively observed in spectrometers and are used to diagnose the magnetic field strength and temperature of the loop structure. Due to the lack of spatial information, the longitudinal…

Solar and Stellar Astrophysics · Physics 2015-07-15 D. Yuan , T. Van Doorsselaere , D. Banerjee , P. Antolin

The chromospheric H-alpha spectral line is a strong line in the spectrum of the Sun and other stars. In the stellar regime, this spectral line is already used as a powerful tracer of stellar activity. For the Sun, other tracers (i.e, CaII…

Solar and Stellar Astrophysics · Physics 2022-05-18 A. Diercke , C. Kuckein , P. W. Cauley , K. Poppenhäger , J. D. Alvarado-Gómez , E. Dineva , C. Denker

We present the first X-ray observation of an oscillation during a stellar flare. The flare occurred on the active M-type dwarf AT Mic and was observed with XMM-Newton. The soft X-ray light curve (0.2-12 keV) is investigated with wavelet…

Astrophysics · Physics 2007-05-23 U. Mitra-Kraev , L. K. Harra , D. R. Williams , E. Kraev

This paper is an attempt to understand the physical processes occurring in different layers of solar atmosphere during a solar flare. For a complete understanding of the flare we must analyze multi-wavelength datasets, as emission at…

Solar and Stellar Astrophysics · Physics 2020-09-30 Shirsh Lata Soni , Radhe Shyam Gupta , Adya Prasad Mishra

Recent high-resolution observations of sunspot oscillations using simultaneously operated ground- and space-based telescopes reveal the intrinsic connection between different layers of the solar atmosphere. However, it is not clear whether…

Solar and Stellar Astrophysics · Physics 2015-10-13 S. Krishna Prasad , D. B. Jess , Elena Khomenko

Oscillations in sunspot umbrae exhibit remarkable differences between the photosphere and chromosphere. We evaluate two competing scenarios proposed for explaining those observations: a chromospheric resonant cavity and waves traveling from…

Solar and Stellar Astrophysics · Physics 2020-08-26 T. Felipe , C. Kuckein , S. J. González Manrique , I. Milic , C. R. Sangeetha

The Hanle effect in strong spectral lines is the physical mechanism that should be increasingly exploited for quantitative explorations of the magnetism of the quiet solar chromospheric plasma. Here we show, by means of multilevel radiative…

Solar and Stellar Astrophysics · Physics 2011-02-25 Jiri Stepan , Javier Trujillo Bueno , Renzo Ramelli , Michele Bianda

On September 21, 2012, we carried out spectral observations of a solar facula in the Si I 10827 {\AA}, He I 10830 {\AA}, and H{\alpha} spectral lines. Later, in the process of analyzing the data, we found a small-scale flare in the middle…

Solar and Stellar Astrophysics · Physics 2018-12-05 Andrei Chelpanov , Nikolai Kobanov

In this work we selected one particular fibril from a high resolution solar chromosphere observation from the Dutch Open Telescope, and tried to obtain a broad picture of the intricate mechanism that might be incorporated in the multiple…

Solar and Stellar Astrophysics · Physics 2015-11-11 Emanuel Sungging Mumpuni , Dhani Herdiwijaya , Mitra Djamal , Thomas Djamaluddin

We present a new automated algorithm to identify, track, and characterize small-scale brightening associated with solar eruptive phenomena observed in H{\alpha}. The temporal spatially-localized changes in chromospheric intensities can be…

Solar and Stellar Astrophysics · Physics 2015-05-30 M. S. Kirk , K. S. Balasubramaniam , J. Jackiewicz , B. J. McNamara , R. T. J. McAteer

Using data from the Helioseismic Magnetic Imager, we report on the amplitudes and phase relations of oscillations in quiet-Sun, plage, umbra and the polarity inversion line (PIL) of an active region NOAA$\#$11158. We employ Fourier, wavelet…

Solar and Stellar Astrophysics · Physics 2021-01-06 A. A. Norton , R. B. Stutz , B. T. Welsch

We present a study of wave processes in the sunspot region NOAA 12670 on 2017 August 10 observed by the Goode Solar Telescope in the TiO 7057 A and Ha 6563 A spectral lines. To study the distribution of power oscillations and their…

Solar and Stellar Astrophysics · Physics 2020-01-15 Robert Sych , Yuzef Zhugzhda , Xiaoli Yan