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Context. The height structure of 3-min oscillations over sunspots is studied in the context of the recently discovered effect of height inversion: over the umbra, the spatial location of the maximum of chromospheric 3-min oscillation power…

Solar and Stellar Astrophysics · Physics 2013-02-11 N. I. Kobanov , D. Y. Kolobov , S. A. Chupin , V. M. Nakariakov

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 problem of solar chromospheric heating remains a challenging one with wider implications for stellar physics. Several studies in the recent past have shown that small-scale inclined magnetic field elements channel copious amount of…

Solar and Stellar Astrophysics · Physics 2018-12-14 S. P. Rajaguru , C. R. Sangeetha , Durgesh Tripathi

We apply ring-diagram analysis and spherical harmonic decomposition methods to compute 3-dimensional power spectra of magnetograms obtained by the Global Oscillation Network Group (GONG) during quiet periods of solar activity. This allows…

Solar and Stellar Astrophysics · Physics 2010-03-29 Kiran Jain , S. C. Tripathy , S. Kholikov , F. Hill

We show that under certain conditions, subsurface structures in the solar interior can alter the average acoustic power observed at the photosphere above them. By using numerical simulations of wave propagation, we show that this effect is…

Solar and Stellar Astrophysics · Physics 2015-05-18 Thomas Hartlep , Alexander G. Kosovichev , Junwei Zhao , Nagi N. Mansour

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

Context. An analysis of the oscillations above sunspots was carried out using simultaneous ground-based and Solar Dynamics Observatory (SDO) observations (SiI 10827A, HeI 10830A, FeI 6173A, 1700A, HeII 304A, FeIX 171A). Aims. Investigation…

Solar and Stellar Astrophysics · Physics 2014-11-25 N. I. Kobanov , A. A. Chelpanov , D. Y. Kolobov

At the surface of the Sun, acoustic waves appear to be affected by the presence of strong magnetic fields in active regions. We explore the possibility that the inclined magnetic field in sunspot penumbrae may convert primarily vertically…

Astrophysics · Physics 2009-11-13 H. Schunker , D. C. Braun , C. Lindsey , P. S. Cally

We report on the spatial distribution of magnetogram oscillatory power and phase angles between velocity and magnetogram signals as observed with the Michelson Doppler Imager. The dataset is 151.25 arcsec times 151.25 arcsec containing…

Astrophysics · Physics 2009-10-31 A. A. Norton , R. K. Ulrich , R. I. Bush , T. D. Tarbell

Coronal fan loops rooted in sunspot umbra show outward propagating waves with subsonic phase speed and period around 3-min. However, their source region in the lower atmosphere is still ambiguous. We performed multi-wavelength observations…

Solar and Stellar Astrophysics · Physics 2023-09-06 Ananya Rawat , Girjesh Gupta

Gravity waves are generated by turbulent subsurface convection overshooting or penetrating locally into a stably stratified medium. While propagating energy upwards, their characteristic negative phase shift over height is a well-recognized…

Solar and Stellar Astrophysics · Physics 2023-07-26 Hirdesh Kumar , Brajesh Kumar , S. P. Rajaguru

We investigate the oscillatory properties of the quiet solar chromosphere in relation to the underlying photosphere, with particular regard to the effects of the magnetic topology. We perform a Fourier analysis on a sequence of…

Astrophysics · Physics 2007-05-23 A. Vecchio , G. Cauzzi , K. P. Reardon , K. Janssen , T. Rimmele

Observations of the solar atmosphere show that internal gravity waves are generated by overshooting convection, but are suppressed at locations of magnetic flux, which is thought to be the result of mode conversion into magneto-acoustic…

Solar and Stellar Astrophysics · Physics 2017-02-01 G. Vigeesh , J. Jackiewicz , O. Steiner

The magnetic field inside the sunspot umbra, as observed by the Full-disk MagnetoGraph (FMG) onboard the Advanced Space based Solar Observatory (ASO-S), was found to be experiencing a weakening. To address this issue, we employed a method…

Solar and Stellar Astrophysics · Physics 2024-05-30 Haiqing Xu , Jiangtao Su , Suo Liu , Yuanyong Deng , Xianyong Bai , Jie Chen , Xiaofan Wang , Xiao Yang , Yongliang Song

In \citet{Stangalini20} and \citet{Deb20}, magnetic oscillations were detected in the chromosphere of a large sunspot and found to be linked to the coronal locations where a First Ionization Potential (FIP) effect was observed. In an…

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

Solar pores are efficient magnetic conduits for propagating magnetohydrodynamic wave energy into the outer regions of the solar atmosphere. Pore observations often contain isolated and/or unconnected structures, preventing the statistical…

Waves are thought to play a significant role in the heating of the solar atmosphere and the acceleration of the wind. Among the many types of waves observed in the Sun, the so-called p-modes with a 3 mHz frequency peak dominate the lower…

Three- and five-minute oscillations of sunspots have different spatial distributions in the solar atmospheric layers. The spatial distributions are crucial to reveal the physical origin of sunspot oscillations and to investigate their…

Solar and Stellar Astrophysics · Physics 2020-02-05 Zhengkai Wang , Song Feng , Linhua Deng , Yao Meng

We investigate the fine structure of magnetic fields in the atmosphere of the quiet Sun. We use photospheric magnetic field measurements from {\sc Sunrise}/IMaX with unprecedented spatial resolution to extrapolate the photospheric magnetic…