Results 11 to 20 of about 3,043 (224)

NANOFLARE ACTIVITY IN THE SOLAR CHROMOSPHERE [PDF]

The Astrophysical Journal, 2014
We use ground-based images of high spatial and temporal resolution to search for evidence of nanoflare activity in the solar chromosphere. Through close examination of more than 10^9 pixels in the immediate vicinity of an active region, we show that the distributions of observed intensity fluctuations have subtle asymmetries.
Jess, D. B., Mathioudakis, M., Keys, P. H.   +2 more
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The Cold Heart of the Solar Chromosphere [PDF]

Symposium - International Astronomical Union, 1994
The early 1990's heralded the deployment of vastly improved space instruments in the ultraviolet (HST) and X-ray (ROSAT) bands, where thermal inhomogeneities in high-excitation chromospheres and coronae are seen in their most favorable light. The infrared spectrum provides a key complementary view of inhomogeneities, but only recently has begun to be ...
Ayres, Thomas (5284981), Ayres, Thomas
openaire   +4 more sources

FARLEY-BUNEMAN INSTABILITY IN THE SOLAR CHROMOSPHERE [PDF]

The Astrophysical Journal, 2009
The Farley-Buneman instability is studied in the partially ionized plasma of the solar chromosphere taking into account the finite magnetization of the ions and Coulomb collisions. We obtain the threshold value for the relative velocity between ions and electrons necessary for the instability to develop.
Gogoberidze, Grigol, Voitenko, Y., Poedts, Stefaan, Goossens, Marcel   +3 more
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Observing the Solar Chromosphere

, 2007
This review is split into two parts: one on chromospheric line formation in answer to the frequent question "where is my line formed", and one presenting state-of-the-art imagery of the chromosphere. In the first part I specifically treat the formation of the Na D lines, Ca II H & K, and Halpha.
Astrophysics, Rutten, R.J., Heinzel, Petr, Dep Natuurkunde, Rutten, Robert J., Dorotovic, Ivan   +5 more
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Insight into the Solar Plage Chromosphere with DKIST [PDF]

The Astrophysical Journal
The strongly coupled hydrodynamic, magnetic, and radiation properties of the plasma in the solar chromosphere make it a region of the Sun's atmosphere that is poorly understood. We use data obtained with the high-resolution Visible Broadband Imager (VBI)
David Kuridze, Han Uitenbroek, Friedrich Wöger, Mihalis Mathioudakis, Huw Morgan, Ryan Campbell, Catherine Fischer, Gianna Cauzzi, Thomas Schad, Kevin Reardon, João M. da Silva Santos, Christian Beck, Alexandra Tritschler, Thomas Rimmele   +13 more
doaj   +4 more sources

On the Rotation of the Solar Chromosphere [PDF]

The Astrophysical Journal, 2020
Abstract Rotation is a significant characteristic of the Sun and other stars, and it plays an important role in understanding their dynamo actions and magnetic activities. In this study, the rotation of the solar chromospheric activity is investigated from a global point of view with an over 40 yr Mg ii index.
Jing-Chen Xu, Peng-Xin Gao, Xiang-Jun Shi   +2 more
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Constraining the Systematics of (Acoustic) Wave Heating Estimates in the Solar Chromosphere

The Astrophysical Journal, 2023
Acoustic wave heating is believed to contribute significantly to the missing energy input required to maintain the solar chromosphere in its observed state.
Momchil E. Molnar, Kevin P. Reardon, Steven R. Cranmer, Adam F. Kowalski, Ivan Milić   +4 more
doaj   +1 more source

Rotational Characteristics of the Solar Transition Region Using SDO/AIA 304 Å Images

The Astrophysical Journal, 2023
To date, the rotational characteristics of the solar transition region remain unclear. In this work, by applying the flux modulation method to the images derived from the Solar Dynamics Observatory/Atmospheric Imaging Assembly between 2011 and 2022 at ...
Qian-Rui Wu, Sheng Zheng, Shu-Guang Zeng, Miao Wan, Xiang-Yun Zeng, Lin-Hua Deng, Yao Huang   +6 more
doaj   +1 more source

Ionisation in the Solar Chromosphere [PDF]

Nature, 1920
IT is well known that the spectrum of the upper layers of the solar chromosphere is chiefly composed of those lines which are relatively more strengthened in the spark than in the arc, and which Sir Norman Lockyer originally styled enhanced lines. The best-known examples are the calcium H and K and the strontium pair (4216, 4077).
openaire   +1 more source

Dissipation of Magnetohydrodynamic Waves in the Solar Stratified Flux Tubes [PDF]

Iranian Journal of Astronomy and Astrophysics, 2023
Chromosphere is the second layer of the Sun with high variability. The increase of the temperature and the decrease of the density are observed in this layer. This unusual behavior is one of the most important problems in the solar corona.
Zahra Fazel
doaj   +1 more source