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Related papers: Rapid Fluctuations in the Lower Solar Atmosphere

200 papers

Motivated by the various examples of spatial variability in the power of the acoustic spectrum, we attempted to look for spatial variability in the peak frequency of the spectrum. However, the determination of this peak frequency on a…

Astrophysics · Physics 2015-06-24 P. Venkatakrishnan , Brajesh Kumar , S. C. Tripathy

Solar five-minute oscillations have been detected in the power spectra of two six-day time intervals from soft X-ray measurements of the Sun observed as a star using the Extreme Ultraviolet Spectrophotometer (ESP) onboard the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2015-06-12 Leonid Didkovsky , Alexander Kosovichev , Darrell Judge , Seth Wieman , Tom Woods

Solar flare accelerated electron beams propagating away from the Sun can interact with the turbulent interplanetary media, producing plasma waves and type III radio emission. These electron beams are detected near the Earth with a double…

Solar and Stellar Astrophysics · Physics 2015-05-19 H. A. S. Reid , E. P. Kontar

Wave theories of heating the chromosphere, corona, and solar wind due to photospheric fluctuations are strengthened by the existence of observed wave coherency up to the transition region (TR). The coherency of solar spicules' intensity…

Solar and Stellar Astrophysics · Physics 2017-02-08 Alireza Ahangarzadeh Maralani , Ehsan Tavabi , Ali Ajabshirizadeh

Finding low-mass planets around solar-type stars requires to understand the physical variability of the host star, which greatly exceeds the planet-induced radial-velocity modulation. This project aims at analyzing - observationally and…

Solar and Stellar Astrophysics · Physics 2025-09-24 Dainis Dravins , Hans-Günter Ludwig

The recently released spacecraft potential measured by the RPW instrument on-board Solar Orbiter has been used to estimate the solar wind electron density in the inner heliosphere. Solar-wind electron density measured during June 2020 has…

Treatments of the radio scattering due to density turbulence in the solar wind typically employ asymptotic approximations to the phase structure function. We use a general structure function (GSF) that straddles the asymptotic limits and…

Solar and Stellar Astrophysics · Physics 2015-09-28 Madhusudan Ingale

We first study the solar flare time sequence based on the GOES16 data. We find that the power spectrum density of the low-energy (E\leq E_{mean}) flare shows 1/f fluctuations, but the high-energy (E>E_{mean}) flare shows a flat spectrum.…

Solar and Stellar Astrophysics · Physics 2023-10-12 Masahiro Morikawa , Akika Nakamichi

The power spectrum of magnetic-field fluctuations in the fast solar wind ($V_{\rm SW}> 500 \mbox{ km} \mbox{ s}^{-1}$) at magnetohydrodynamic (MHD) scales is characterized by two different power laws on either side of a break frequency…

Measurements of fluctuations of electric fields in the frequency range from a fraction of one Hz to 12.5 Hz are presented, and corrected for the Lorentz transformation of magnetic fluctuations to give the electric fields in the plasma…

Space Physics · Physics 2009-11-11 P. J. Kellogg , S. D. Bale , F. S. Mozer , T. S. Horbury , H. Reme

Observation of Interplanetary Scintillation (IPS) provides an important and effective way to study the solar wind and the space weather. A series of IPS observations were conducted by the Five-hundred-meter Aperture Spherical radio…

Solar and Stellar Astrophysics · Physics 2022-08-03 Li-Jia Liu , Bo Peng , Lei Yu , Bin Liu , Ji-Guang Lu , Ye-Zhao Yu , Hong-Wei Xi , Ming Xiong , O. Chang

Magnetic fluctuations in the solar wind are distributed according to Kolmogorov's power law $f^{-5/3}$ below the ion cyclotron frequency $f_{ci}$. Above this frequency, the observed steeper power law is usually interpreted in two different…

Astrophysics · Physics 2009-11-13 O. Alexandrova , V. Carbone , P. Veltri , L. Sorriso-Valvo

We search for signatures of high-frequency oscillations in the upper solar photosphere and low chromosphere in the context of acoustic heating of outer stellar atmospheres. We use ultraviolet image sequences of a quiet center-disk area from…

Astrophysics · Physics 2009-06-23 A. G. de Wijn , R. J. Rutten , T. D. Tarbell

We determine the frequencies of solar oscillations covering a wide range of degree (100< l <4000) and frequency (1.5 <\nu<10 mHz) using the ring diagram technique applied to power spectra obtained from MDI (Michelson Doppler Imager) data.…

Astrophysics · Physics 2009-10-31 H. M. Antia , Sarbani Basu

Large-scale compressive slow-mode-like fluctuations can cause variations in the density, temperature, and magnetic-field magnitude in the solar wind. In addition, they also lead to fluctuations in the differential flow $U_{\rm p\alpha}$…

Space Physics · Physics 2023-08-07 Xingyu Zhu , Daniel Verscharen , Jiansen He , Bennett A. Maruca , Christopher J. Owen

We focus on Hinode Solar Optical Telescope (SOT) calcium II H-line observations of a solar quiescent prominence (QP) that exhibits highly variable dynamics suggestive of turbulence. These images capture a sufficient range of scales…

Solar and Stellar Astrophysics · Physics 2015-05-30 Ersilia Leonardis , Sandra C. Chapman , Claire Foullon

Atmospheric water vapor causes significant undesired phase fluctuations for the Submillimeter Array (SMA) interferometer, particularly in its highest frequency observing band of 690 GHz. One proposed solution to this atmospheric effect is…

Astrophysics · Physics 2007-05-23 D. Y. Kubo , T. R. Hunter , R. D. Christensen , P. I. Yamaguchi

In this research, we investigate Explosive Events (EEs) in the off-limb solar atmosphere, with simultaneous observations from the Si IV, Mg II k, and slit-jaw images (SJI) of the Interface Region Imaging Spectrograph (IRIS), on 17 August…

Solar and Stellar Astrophysics · Physics 2022-07-06 E. Tavabi , S. Zeighami , M. Heydari

The bulk of the radiative output of a solar flare is emitted from the chromosphere, which produces enhancements in the optical and UV continuum, and in many lines, both optically thick and thin. We have, until very recently, lacked…

Solar and Stellar Astrophysics · Physics 2015-10-07 Graham S. Kerr , Paulo J. A. Simões , Jiong Qiu , Lyndsay Fletcher

Oscillations were observed across the whole solar disk using the Doppler shift and line depth of spectral lines from the CO molecule near 4666~nm with the National Solar Observatory's McMath/Pierce solar telescope. Power, coherence, and…

Solar and Stellar Astrophysics · Physics 2015-05-20 Matthew Penn , Tom Schad , Erin Cox