Results 111 to 120 of about 41,638 (224)

Waiting Time Distribution of Supra-arcade Downflows

The Astrophysical Journal Letters
Supra-arcade downflows (SADs) are dark, sunward-moving structures above the arcade of flare loops. Naturally, they are considered to be associated with outflows resulting from magnetic reconnection at the vertical current sheet beneath the eruptive ...
Zichao Yang, Rui Liu
doaj   +1 more source

A Double-decker Flux Rope Model for the Solar Eruption on 2012 March 10

The Astrophysical Journal
We present a magnetic configuration of a compound solar eruption observed on 2012 March 10, from NOAA AR 11429 near the disk center, which displayed a soft X-ray sigmoid before the eruption.
Nishu Karna, Suman Dhakal, Antonia Savcheva, Jie Zhang, Bernhard Kliem   +4 more
doaj   +1 more source

The average solar wind in the inner heliosphere: Structures and slow variations [PDF]

, 1983
Measurements from the HELIOS solar probes indicated that apart from solar activity related disturbances there exist two states of the solar wind which might result from basic differences in the acceleration process: the fast solar wind (v 600 kms(-)1 ...
Schwenn, R.
core   +1 more source

Direct Measurements of Magnetic Twist in the Solar Corona

, 2012
In the present work we study evolution of magnetic helicity in the solar corona. We compare the rate of change of a quantity related to the magnetic helicity in the corona to the flux of magnetic helicity through the photosphere and find that the two ...
A. Malanushenko, Alissandrakis, Aschwanden, Burnette, Chae, D. W. Longcope, DeRosa, Finn, Georgoulis, Lim, Longcope, Longcope, M. H. Yusuf, Malanushenko, Malanushenko, Park, Pearson, Pevtsov, Prautzsch, Press, Welsch, Welsch, Welsch   +22 more
core   +1 more source

Exploring the Coronal Magnetic Field with Galactic Cosmic Rays: The Sun Shadow Observed by HAWC

The Astrophysical Journal
Galactic cosmic rays (GCRs) are charged particles that reach the heliosphere almost isotropically in a wide energy range. In the inner heliosphere, the GCR flux is modulated by solar activity so that only energetic GCRs reach the lower layers of the ...
R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, K. P. Arunbabu, D. Avila Rojas, R. Babu, E. Belmont-Moreno, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, P. Colín-Farias, U. Cotti, J. Cotzomi, S. Coutiño de León, E. De la Fuente, C. de León, D. Depaoli, R. Diaz Hernandez, J. C. Díaz-Vélez, M. Durocher, M. A. DuVernois, K. Engel, C. Espinoza, K. L. Fan, N. Fraija, J. A. García-González, F. Garfias, A. Gonzalez Muñoz, M. M. González, J. A. Goodman, J. P. Harding, D. Huang, F. Hueyotl-Zahuantitla, A. Iriarte, S. Kaufmann, A. Lara, J. Lee, H. León Vargas, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, J. Martínez-Castro, J. A. Matthews, P. Miranda-Romagnoli, E. Moreno, M. Mostafá, A. Nayerhoda, L. Nellen, T. Niembro, R. Noriega-Papaqui, N. Omodei, E. G. Pérez-Pérez, C. D. Rho, D. Rosa-González, E. Ruiz-Velasco, J. Ryan, H. Salazar, D. Salazar-Gallegos, A. Sandoval, J. Serna-Franco, A. J. Smith, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Turner, F. Ureña-Mena, E. Varela, L. Villaseñor, X. Wang, I. J. Watson, E. Willox, S. Yun-Cárcamo, H. Zhou   +76 more
doaj   +1 more source

The X-ray cycle in the solar-type star HD 81809

, 2008
(abridged) Our long-term XMM-Newton program of long-term monitoring of a solar-like star with a well-studied chromospheric cycle, HD 81809 aims to study whether an X-ray cycle is present, along with studying its characteristics and its relation to the ...
Baliunas, F. Favata, Favata, G. Micela, Hempelmann, Hempelmann, Hempelmann, J. H. M. M. Schmitt, J. Hall, Judge, Orlando, Orlando, Orlando, Peres, Pourbaix, Robrade, S. Orlando, S. Sciortino, Schmitt, Soderblom, Takeda, Tsuneta   +21 more
core   +1 more source

Properties of Slow Magnetoacoustic Waves Observed Simultaneously Using Hi-C 2.1 and AIA

The Astrophysical Journal
Propagating slow magnetoacoustic waves are commonly observed in different coronal structures but are most prominent in active region fan loops. Their rapid damping with damping lengths of the order of a wavelength has been investigated in the past by ...
Suraj K. Tripathy, S. Krishna Prasad, D. Banerjee   +2 more
doaj   +1 more source

A model for heating the super-hot corona in solar active regions

Nature Astronomy
What physical mechanisms heat the outer solar or stellar atmosphere to million-Kelvin temperatures is a fundamental but long-standing open question. In particular, the solar corona in active region cores contains an even hotter component reaching ten million Kelvin, manifesting as persistent coronal loops in extreme ultraviolet and soft X-ray images ...
Zekun Lu, Feng Chen, M. D. Ding, Can Wang, Yu Dai, Xin Cheng   +5 more
openaire   +2 more sources

A Near-half-century Simulation of the Solar Corona

The Astrophysical Journal Letters
We present an overview of results from a magnetofrictional model of the entire solar corona over a period of 47 yr. The simulation self-consistently reproduces decades of solar phenomena, varying in duration between rapid eruptions and the long-term ...
Valentin Aslanyan, Karen A. Meyer, Roger B. Scott, Anthony R. Yeates   +3 more
doaj   +1 more source

131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare Onset

The Astrophysical Journal Letters
Thermal changes in coronal loops are well studied, both in quiescent active regions and in flaring scenarios. However, relatively little attention has been paid to loop emission in the hours before the onset of a solar flare; here, we present the ...
Kara L. Kniezewski, E. I. Mason, Vadim M. Uritsky, Seth H. Garland   +3 more
doaj   +1 more source