English
Related papers

Related papers: Multi-layer study of wave propagation in sunspots

200 papers

In this work, we present a study of the propagation of low-frequency magneto-acoustic waves into the solar chromosphere within small-scale inclined magnetic fields over a quiet-magnetic network region utilizing near-simultaneous…

Solar and Stellar Astrophysics · Physics 2023-04-27 Hirdesh Kumar , Brajesh Kumar , S. P. Rajaguru , Shibu K. Mathew , Ankala Raja Bayanna

Observations of chromospheric spectral lines near and beyond the solar limb provide information on the solar chromosphere without any photospheric contamination. For ground-based observations near and off the limb with real-time image…

Solar and Stellar Astrophysics · Physics 2012-03-12 C. Beck , R. Rezaei

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

Solar filaments exist as stable structures for extended periods of time before many of them form the core of a CME. We examine the properties of an erupting filament on 2017 May 29--30 with high-resolution He I 10830 A and Halpha spectra…

The heating of the Sun's chromosphere remains poorly understood. While progress has been made on understanding what drives the quiet Sun internetwork chromosphere, chromospheric heating in strong magnetic field regions continues to present…

Solar and Stellar Astrophysics · Physics 2013-02-07 J. de la Cruz Rodríguez , B. De Pontieu , M. Carlsson , L. H. M. Rouppe van der Voort

Solar oscillations are expected to be excited by turbulent flows in the intergranular lanes near the solar surface. Time series recorded by the IMaX instrument aboard the {\sc Sunrise} observatory reveal solar oscillations at high…

Sunspots are locations on the Sun where unique atmospheric conditions prevail. In particular, the very low temperatures found above sunspots allow the emission of H_2 lines. In this study we are interested in the radiation emitted by…

Astrophysics · Physics 2007-05-23 Nicolas Labrosse , Huw Morgan , Shadia Rifai Habbal , Daniel Brown

The He I 10830{\AA} line, a crucial optically thin chromospheric line, is frequently used to study coronal heating and vertical coupling across the chromosphere-corona interface. However, its images are severely contaminated by the strong…

Solar and Stellar Astrophysics · Physics 2026-05-26 Huaiming Li , Fangyu Xu , Yi Bi , Zhenyu Jin

We present results derived from the analysis of spectropolarimetric measurements of active region AR12546, which represents one of the largest sunspots to have emerged onto the solar surface over the last $20$ years. The region was observed…

Solar and Stellar Astrophysics · Physics 2018-12-26 M. Stangalini , S. Jafarzadeh , I. Ermolli , R. Erdélyi , D. B. Jess , P. H. Keys , F. Giorgi , M. Murabito , F. Berrilli , D. Del Moro

Eruptive activity in the solar corona can often lead to the propagation of shock waves. In the radio domain the primary signature of such shocks are type II radio bursts, observed in dynamic spectra as bands of emission slowly drifting…

The detection of Earth-like planets with the radial-velocity method is currently limited by the presence of stellar activity signatures. On rotational timescales, spots and plages (or faculae) are known to introduce different RV signals,…

Solar and Stellar Astrophysics · Physics 2023-10-25 M. Cretignier , A. G. M. Pietrow , S. Aigrain

Low-amplitude Doppler-shift oscillations have been observed in coronal emission lines in a number of active regions with the EUV Imaging Spectrometer (EIS) on the Hinode satellite. Both standing and propagating waves have been detected and…

Solar and Stellar Astrophysics · Physics 2015-05-18 John T. Mariska , K. Muglach

The study of the differential rotation in the chromosphere of the Sun is of significant importance as it provides valuable insights into the rotational behaviour of the solar atmosphere at higher altitudes and the coupling mechanism between…

Solar and Stellar Astrophysics · Physics 2024-12-25 Dibya Kirti Mishra , Srinjana Routh , Bibhuti Kumar Jha , Subhamoy Chatterjee , Dipankar Banerjee

We explore imprints of the solar wind interaction with the local interstellar medium on spectral properties of the backscattered solar Ly-alpha radiation. We employ newly developed effective model for the interstellar H atom velocity…

Solar and Stellar Astrophysics · Physics 2015-05-27 Olga A. Katushkina , Vladislav V. Izmodenov

We seek to clarify the nature of running penumbral (RP) waves: are they chromospheric trans-sunspot waves or a visual pattern of upward-propagating waves? Full Stokes spectropolarimetric time series of the photospheric Si I 10827 \AA line…

Astrophysics · Physics 2009-11-13 D. Shaun Bloomfield , Andreas Lagg , Sami K. Solanki

We analyze decay phase observations of the GOES class C6.7 flare SOL2022-08-19T20:31 by the Visible Spectropolarimeter (ViSP) on the National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST). The data include the first…

We analyze a solar active region observed by the Hinode CaII H line using the time-distance helioseismology technique, and infer wave-speed perturbation structures and flow fields beneath the active region with a high spatial resolution.…

Solar and Stellar Astrophysics · Physics 2014-11-20 Junwei Zhao , Alexander G. Kosovichev , Takashi Sekii

An analysis of line-of-sight velocity oscillation in nine solar faculae was undertaken with the aim of studying of phase relations between chromosphere (He i 10830 A line) and photosphere (Si i 10827 A line) five-minute oscillations. We…

Solar and Stellar Astrophysics · Physics 2015-05-30 N. I. Kobanov , A. S. Kustov , S. A. Chupin , V. A. Pulyaev

We investigate how helioseismic waves that originate from effective point sources interact with a sunspot. These waves are reconstructed from observed stochastic wavefields on the Sun by cross-correlating photospheric Doppler-velocity…

Solar and Stellar Astrophysics · Physics 2015-05-20 Junwei Zhao , Alexander G. Kosovichev , Stathis Ilonidis

We use radiation hydrodynamic simulations to examine two models of solar flare chromospheric heating: Alfv\'en wave dissipation and electron beam collisional losses. Both mechanisms are capable of strong chromospheric heating, and we show…

Solar and Stellar Astrophysics · Physics 2016-08-17 Graham S. Kerr , Lyndsay Fletcher , Alexander J. B. Russell , Joel C. Allred
‹ Prev 1 3 4 5 6 7 10 Next ›