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Context. Understanding the close relationship between the plasma and the magnetic field is important to describe and explain the observed complex dynamics of solar prominences. Aims. We determine if a close relationship between plasma and…

Solar and Stellar Astrophysics · Physics 2017-11-01 P. J. Levens , N. Labrosse , B. Schmieder , A. López Ariste , L. Fletcher

We analyze coordinated Hinode XRT and EIS observations of a non-flaring active region to investigate the thermal properties of coronal plasma taking advantage of the complementary diagnostics provided by the two instruments. In particular…

Solar and Stellar Astrophysics · Physics 2015-05-20 Paola Testa , Fabio Reale , Enrico Landi , Ed DeLuca , Vinay Kashyap

The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that…

Solar and Stellar Astrophysics · Physics 2015-05-28 Amy Winebarger , Joan Schmelz , Harry Warren , Steve Saar , Vinay Kashyap

Coronal loops are the basic structures of the solar transition region and corona. The understanding of physical mechanism behind the loop heating, plasma flows, and filling are still considered a major challenge in the solar physics. The…

Solar and Stellar Astrophysics · Physics 2015-02-24 G. R. Gupta , Durgesh Tripathi , Helen E. Mason

It is well established that elemental abundances vary in the solar atmosphere and that this variation is organized by first ionization potential (FIP). Previous studies have shown that in the solar corona low-FIP elements, such as Fe, Si,…

Solar and Stellar Astrophysics · Physics 2016-06-22 Harry P. Warren , David H. Brooks , George A. Doschek , Uri Feldman

Our aim is to determine the plasma properties of a coronal bright point and compare its magnetic topology extrapolated from magnetogram data with its appearance in X-ray images. We analyse spectroscopic data obtained with EIS/Hinode, Ca II…

Astrophysics · Physics 2008-10-07 D. Pérez-Suárez , R. C. Maclean , J. G. Doyle , M. S. Madjarska

The solar corona is much hotter than the photosphere and chromosphere, but the physical mechanism responsible for heating the coronal plasma remains unidentified yet. The thermal microwave emission, which is produced in strong magnetic…

Solar and Stellar Astrophysics · Physics 2025-08-27 Alexey A. Kuznetsov , Gregory D. Fleishman , Gelu M. Nita , Sergey A. Anfinogentov

We present observations of high temperature emission in the core of a solar active region using instruments on Hinode and SDO. These multi-instrument observations allow us to determine the distribution of plasma temperatures and follow the…

Solar and Stellar Astrophysics · Physics 2015-05-20 Harry P. Warren , David H. Brooks , Amy R. Winebarger

The intensity of the \oiv~2s$^{2}$ 2p $^{2}$P-2s2p$^{2}$ $^{4}$P and \siv~3 s$^{2}$ 3p $^{2}$P- 3s 3p$^{2}$ $^{4}$ P intercombination lines around 1400~\AA~observed with the \textit{Interface Region Imaging Spectrograph} (IRIS) provide a…

Solar and Stellar Astrophysics · Physics 2016-10-19 V. Polito , G. Del Zanna , J. Dudík , H. E. Mason , A. Giunta , K. K. Reeves

We determine magnetic fields from the photosphere to the upper chromosphere combining data from the Hinode satellite and the CLASP2.1 sounding rocket experiment. CLASP2.1 provided polarization profiles of the Mg~{|sc ii} $h$ and $k$ lines,…

Decaying active region 10942 is investigated from 4:00-16:00 UT on February 24, 2007 using a suite of EUV observing instruments. Results from Hinode/EIS, STEREO and TRACE show that although the active region has decayed and no sunspot is…

Solar and Stellar Astrophysics · Physics 2015-05-30 Jason Scott , P. C. H. Martens , David McKenzie

In this paper, we report the observed temporal correlation between extreme-violet (EUV) emission and magneto-acoustic oscillations in a EUV moss region, which is the footpoint region only connected by magnetic loops with million-degree…

Solar and Stellar Astrophysics · Physics 2021-06-02 Parida Hashim , Zhenxiang Hong , Haisheng Ji , Jinhua Shen , Kaifan Ji , Wenda Cao

The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of the upper transition region moss at an unprecedented spatial (~0.3-0.4 arcsec) and temporal (5.5s) resolution. The Hi-C observations show in some moss regions…

With the recent launch of the Hinode satellite our view of the nature and evolution of quiet-Sun regions has been improved. In light of the new high resolution observations, we revisit the study of the quiet Sun's topological nature.…

Astrophysics · Physics 2009-11-13 S. Regnier , C. E. Parnell , A. L. Haynes

Constraining the frequency of energy deposition in magnetically-closed active region cores requires sophisticated hydrodynamic simulations of the coronal plasma and detailed forward modeling of the optically-thin line-of-sight integrated…

Solar and Stellar Astrophysics · Physics 2021-10-13 W. T. Barnes , S. J. Bradshaw , N. M. Viall

In order to better understand the nature of active region outflows, the electron density was measured by using a density-sensitive line pair Fe xiv 264.78A/274.20A.Since coronal line profiles of the outflow region are composed of a major…

Solar and Stellar Astrophysics · Physics 2015-06-03 Naomasa Kitagawa , Takaaki Yokoyama

Active regions often show S-shaped structures in the corona called sigmoids. These are highly sheared and twisted loops formed along the polarity inversion line. They are considered to be one of the best pre-eruption signatures for CMEs.…

Solar and Stellar Astrophysics · Physics 2021-03-31 Sargam M. Mulay , Durgesh Tripathi , Helen Mason

The Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) and the Hinode/ EUV Imaging Spectrometer (EIS) observed AR 11726 on 2013 April 23. We present intensity images in numerous atomic lines constructed from these observations. These…

Solar and Stellar Astrophysics · Physics 2018-07-03 Joel Allred , Adrian Daw , Jeffrey Brosius

Knowledge of the electron density distribution in the solar corona put constraints on the magnetic field configurations for coronal modeling and on initial conditions for solar wind modeling. We work with polarized SOHO/LASCO-C2 images from…

Solar and Stellar Astrophysics · Physics 2015-12-15 Judith de Patoul , Claire Foullon , Pete Riley

The outer atmosphere of the Sun is composed of plasma heated to temperatures well in excess of the visible surface. We investigate short cool and warm (<1 MK) loops seen in the core of an active region to address the role of field-line…