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Observational detection of quasi-periodic drifting fine structures in a type III radio burst associated with a solar flare SOL2015-04-16T11:22, with Low Frequency Array, is presented. Although similar modulations of the type III emission…

Solar and Stellar Astrophysics · Physics 2018-07-11 Dmitrii Y. Kolotkov , Valery M. Nakariakov , Eduard P. Kontar

We have observed evidence for $p$-mode oscillations in the G0 IV star etaBoo (V = 2.68). This represents the first clear evidence of solar-like oscillations in a star other than the Sun. We used a new technique which measures fluctuations…

Astrophysics · Physics 2009-10-22 Hans Kjeldsen , Timothy R. Bedding , Michael Viskum , Soeren Frandsen

The most energetic flares start with a filament rise followed by magnetic reconnection below this filament. The start of the reconnection corresponds to the beginning of the flare impulsive phase. In this paper we study processes before…

Solar and Stellar Astrophysics · Physics 2020-04-02 Marian Karlicky , Jana Kasparova , Robert Sych

Waves are an integral part of the solar atmosphere, and their characteristics (e.g., dominant period, range of periods, power, and phase angle) change on a diverse spatio-temporal scale. It is well well-established observationally that the…

Solar and Stellar Astrophysics · Physics 2025-06-10 Pradeep Kayshap , K. Murawski , Z. E. Musielak , Suresh Babu

Quasi-periodic disturbances have been observed in the outer solar atmosphere for many years now. Although first interpreted as upflows (Schrijver et al. (1999)), they have been widely regarded as slow magnetoacoustic waves, due to observed…

Solar and Stellar Astrophysics · Physics 2015-06-05 G. Kiddie , I. De Moortel , G. Del Zanna , S. W. McIntosh , I. Whittaker

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

Solar flares are powerful particle accelerators, and in the accepted standard flare model most of the flare energy is transported from a coronal energy-release region by accelerated electrons which stop collisionally in the chromosphere,…

Solar and Stellar Astrophysics · Physics 2024-06-18 Paulo J. A. Simões , Lyndsay Fletcher , Hugh S. Hudson , Graham S. Kerr , Matt Penn , Karla F. Lopez

We analyze high-cadence vector magnetograms (135~s) and flare-ribbon observations of 37 flares from the Solar Dynamics Observatory to understand the spatial and temporal properties of changes in the photospheric vector magnetic field and…

Solar and Stellar Astrophysics · Physics 2023-03-08 Rahul Yadav , Maria D. Kazachenko

A common feature of electromagnetic emission from solar flares is the presence of intensity pulsations that vary as a function of time. Known as quasi-periodic pulsations (QPPs), these variations in flux appear to include periodic…

Solar and Stellar Astrophysics · Physics 2021-04-14 Brendan P. Clarke , Laura A. Hayes , Peter T. Gallagher , Shane A. Maloney , Eoin P. Carley

We investigate the decayless regime of coronal kink oscillations recently discovered in the Solar Dynamics Observatory (SDO)/AIA data. In contrast to decaying kink oscillations that are excited by impulsive dynamical processes, this type of…

Solar and Stellar Astrophysics · Physics 2015-11-18 S. A. Anfinogentov , V. M. Nakariakov , G. Nisticò

We present a detailed investigation of the Doppler shift oscillations in a hot loop during an M7.1 flare on 2014 October 27 observed by the Interface Region Imaging Spectrograph. The periodic oscillations are observed in the Doppler shift…

Solar and Stellar Astrophysics · Physics 2017-11-15 Dong Li , Zongjun Ning , Yu Huang , N. -H. Chen , Qingmin Zhang , Yingna Su , Wei Su

We have made high resolution observations of the Sun in which we identify individual sunquakes and see power from these seismic events being pumped into the resonant modes of vibration of the Sun. A typical event lasts about five minutes.…

Astrophysics · Physics 2009-10-30 P. L. Goode , L. H. Strous , T. R. Rimmele , R. T. Stebbins

It is expected that energetic solar flares releasing large amount of energy at the photosphere may be able to excite the acoustic ($p$-) modes of oscillations. We have determined the characteristic properties of mode parameters by applying…

Solar and Stellar Astrophysics · Physics 2014-11-20 R. A. Maurya , A. Ambastha , S. C. Tripathy

In this work, we studied oscillation parameters in faculae above magnetic knots and in the adjacent to them areas. Using SDO data we analysed oscillations in magnetic strength, Doppler velocity, and intensity signals for the lower…

Solar and Stellar Astrophysics · Physics 2016-08-17 Andrei A. Chelpanov , Nikolai I. Kobanov , Dmitry Y. Kolobov

Quiescent filaments are usually affected by internal and/or external perturbations triggering oscillations of different kinds. In particular, external large-scale coronal waves can perturb remote quiescent filaments leading to…

We analyze flare-associated transverse oscillations in a quiescent solar prominence on 8-9 September, 2010. Both the flaring active region and the prominence were located near the West limb, with a favorable configuration and viewing angle.…

Solar and Stellar Astrophysics · Physics 2015-06-11 Sanjay Gosain , Claire Foullon

We present observations of an eruptive solar flare on 2016 January 6 that occurred behind the solar limb from the perspective of the Earth, but was well observed by STEREO and the Solar Extreme Ultraviolet Monitor on the Mars Atmosphere and…

Small cyclic variations in the frequencies of acoustic modes are expected to be a common phenomenon in solar-like pulsators, as a result of stellar magnetic activity cycles. The frequency variations observed throughout the solar and stellar…

Solar and Stellar Astrophysics · Physics 2015-06-12 A. R. G. Santos , M. S. Cunha , J. J. G. Lima

In the solar atmosphere, the acoustic cutoff frequency is a local quantity which depends on the atmospheric height. It separates the low-frequency evanescent waves from the high-frequency propagating waves. We measure the cutoff frequency…

Solar and Stellar Astrophysics · Physics 2018-09-19 T. Felipe , C. Kuckein , I. Thaler

We analyze and interpret SOHO/MDI data on oscillation frequency changes between 1996 and 2004 focusing on differences between activity minimum and maximum of solar cycle 23. We study only the behavior of the centroid frequencies, which…

Astrophysics · Physics 2009-11-10 W. A. Dziembowski , P. R. Goode