Results 71 to 80 of about 11,368 (206)

Tearing modes in solar coronal loops

The Astrophysical Journal, 1990
It is shown that solar coronal-like magnetic loops, that is loops emerging from and reentering heavy plasma, are unstable to tearing modes. In particular, the previously made assumption of line tying to the heavy plasma, resulting in stabilization, is shown to be inapplicable because the growth rate is sub-Alfvenic in the entire loop, including the ...
openaire   +1 more source

Searching for Rotational X‐Ray Modulation on TIC 277539431

Astronomische Nachrichten, Volume 347, Issue 3, March 2026.
ABSTRACT TIC 277539431, a fast rotating M7 dwarf, was detected to host the highest latitude flare to date at 81°$$ {81}^{{}^{\circ}} $$. Magnetic activity like stellar flares occurring at high latitude indicate occurrence of coronal loops at these latitudes on fully‐convective M dwarfs. In contrast, sunspots usually occur below 30°$$ {30}^{{}^{\circ}} $
Desmond Dsouza, Katja Poppenhäger, Ekaterina Ilin   +2 more
wiley   +1 more source

Two Distinctly Different Characteristics of Flare-driven Coronal Rain Revealed from High-resolution Spectroscopic Imaging Observations with FISS/GST

The Astrophysical Journal
We report on a flare-driven coronal rain event observed along postflare loops during the decay phase of an X1.6-class solar flare. Although high-resolution studies of flare-driven coronal rain have been conducted, imaging spectroscopic studies are rare ...
Donguk Song, Eun-Kyung Lim, Jongchul Chae, Maria S. Madjarska, Masahito Kubo, Hannah Kwak, Juhyung Kang, Ryohtaroh T. Ishikawa, Kyoung-Sun Lee   +8 more
doaj   +1 more source

Coronal rain in magnetic bipolar weak fields

, 2017
We intend to investigate the underlying physics for the coronal rain phenomenon in a representative bipolar magnetic field, including the formation and the dynamics of coronal rain blobs. With the MPI-AMRVAC code, we performed three dimensional radiative
Fang, Xia, Keppens, Rony, Xia, Chun
core   +1 more source

The Heating of Solar Coronal Loops by Alfvén Wave Turbulence [PDF]

The Astrophysical Journal, 2017
Abstract In this paper we further develop a model for the heating of coronal loops by Alfvén wave turbulence (AWT). The Alfvén waves are assumed to be launched from a collection of kilogauss flux tubes in the photosphere at the two ends of the loop.
A. A. van Ballegooijen, M. Asgari-Targhi, A. Voss   +2 more
openaire   +4 more sources

Continuous upflows and sporadic downflows observed in active regions

, 2011
We present a study of the temporal evolution of coronal loops in active regions and its implications for the dynamics in coronal loops. We analyzed images of the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) at multiple ...
Antolin, Aschwanden, Aschwanden, Culhane, De Pontieu, De Pontieu, Freeland, H. Peter, Hara, Kamio, Kjeldseth-Moe, Kosugi, Müller, Müller, Müller, O’Dwyer, Peter, S. K. Solanki, S. Kamio, Schrijver, Tripathi, Ugarte-Urra, W. Curdt, Warren, Warren, Warren, Winebarger   +26 more
core   +1 more source

Flare-generated acoustic oscillations in solar and stellar coronal loops [PDF]

Astronomy & Astrophysics, 2004
Low-frequency longitudinal oscillations of a flaring coronal loop are studied numerically. In the recent work of Nakariakov et al., Astron. and Astrophys., 414, L25-L28 (2004) it has been shown that the time dependences of density and velocity in a flaring loop contain well-pronounced quasi-harmonic oscillations associated with a 2nd harmonic of a ...
Tsiklauri, D., Nakariakov, V. M. (Valery M.), Arber, T. D., Aschwanden, Markus J.   +3 more
openaire   +3 more sources

Calibrating Probabilistic Solar‐Wind Forecasts Driven by the Wang‐Sheeley‐Arge Model

Space Weather, Volume 24, Issue 3, March 2026.
Abstract By spatially perturbing coronal model output within a coupled coronal‐heliospheric model we can generate probabilistic predictions of solar‐wind speed. We apply these spatial perturbations to the Wang‐Sheeley‐Arge (WSA) model output to generate large sets of input conditions for the Heliospheric Upwind eXtrapolation with time dependence (HUXt)
N. O. Edward‐Inatimi, M. J. Owens, L. Barnard, H. Turner, M. Marsh, S. Gonzi, M. Lang   +6 more
wiley   +1 more source

Modeling the Propagation of Slow Magnetoacoustic Waves in a Multistranded Coronal Loop

The Astrophysical Journal
We study the propagation properties of slow magnetoacoustic waves in a multithermal coronal loop using a 3D MHD model, for the first time. A bundle of 33 vertical cylinders, each of 100 km radius, randomly distributed over a circular region of radius 1 ...
S. Krishna Prasad, T. Van Doorsselaere
doaj   +1 more source

High Voltage DC Active Current Injection to Simulate Geomagnetically Induced Currents in New Zealand

Space Weather, Volume 24, Issue 3, March 2026.
Abstract This study investigates the effects of geomagnetically induced currents (GIC) on New Zealand's electrical infrastructure via an intentional ground injection of direct current (DC) from a high voltage DC converter station. GIC manifests as quasi‐DC currents within power systems, potentially causing transformer saturation, increased reactive ...
Soren Subritzky, Andrew Lapthorn, Stewart Hardie, Paul Agger, Mike Dalzell, Mark A. Clilverd, Neil Cobbett, Ciaran Beggan, Juliane Hübert, Eliot Eaton, James B. Brundell, Craig J. Rodger   +11 more
wiley   +1 more source