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Related papers: EUV Analysis of a Quasi-Static Coronal Loop Struct…

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We report on the SDO/AIA and Hinode/EIS observations of a transient coronal loop. The loop brightens up in the same location after the disappearance of an arcade formed during a B8.9-class microflare three hours earlier. EIS captures this…

We present the first model that couples the formation of the corona of a solar active region to a model of the emergence of a sunspot pair. This allows us to study when, where, and why active region loops form, and how they evolve. We use a…

Solar and Stellar Astrophysics · Physics 2014-05-08 F. Chen , H. Peter , S. Bingert , M. C. M. Cheung

Coronal loops are building blocks of solar active regions. However, their formation mechanism is still not well understood. Here we present direct observational evidence for the formation of coronal loops through magnetic reconnection as…

Solar and Stellar Astrophysics · Physics 2021-07-14 Zhenyong Hou , Hui Tian , Hechao Chen , Xiaoshuai Zhu , Zhenghua Huang , Xianyong Bai , Jiansen He , Yongliang Song , Lidong Xia

We analyze high cadence high resolution observations of a C3.2 flare obtained by AIA/SDO on August 1, 2010. The flare is a long duration event with soft X-ray and EUV radiation lasting for over four hours. Analysis suggests that magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-03 Jiong Qiu , Wen-Juan Liu , Dana W. Longcope

Using data obtained by the EUV Imaging Spectrometer (EIS) onboard Hinode, we have per- formed a survey of obvious and persistent (without significant damping) Doppler shift oscillations in the corona. We have found mainly two types of…

Solar and Stellar Astrophysics · Physics 2012-10-31 Hui Tian , Scott W. McIntosh , Tongjiang Wang , Leon Ofman , Bart De Pontieu , Davina E. Innes , Hardi Peter

We investigate the evolution of coronal loop emission in the context of the coronal magnetic field topology. New modeling techniques allow us to investigate the magnetic field structure and energy release in active regions. Using these…

Solar and Stellar Astrophysics · Physics 2015-05-19 J. -Y. Lee , Graham Barnes , K. D. Leka , Katharine K. Reeves , K. E. Korreck , L. Golub , E. E. DeLuca

Propagating disturbances are often observed in active region fan-like coronal loops. They were thought to be due to slow mode MHD waves based on some of the observed properties. But the recent studies involving spectroscopy indicate that…

Solar and Stellar Astrophysics · Physics 2015-11-11 S. Mandal , T. Samanta , D. Banerjee , S. Krishna Prasad , L. Teriaca

The prominent blue shifts of Ne viii associated with the junctions of the magnetic network in the quiet Sun are still not well understood. By comparing the coronal magnetic-field structures as obtained by a potential-field reconstruction…

Solar and Stellar Astrophysics · Physics 2014-11-20 Hui Tian , Eckart Marsch , Werner Curdt , Jiansen He

In this study we report detailed observations of magnetic environment at four footpoints of two warm coronal loops observed on 5 May 2016 in NOAA AR 12542 (Loop I) and 17 Dec 2015 in NOAA AR 12470 (Loop II). These loops were connecting a…

Solar and Stellar Astrophysics · Physics 2019-03-29 Seray Şahin , Vasyl Yurchyshyn , Pankaj Kumar , Ali Kilcik , Kwangsu Ahn , Xu Yang

On 17 January 2010, STEREO-B observed in extreme ultraviolet (EUV) and white light a large-scale dome-shaped expanding coronal transient with perfectly connected off-limb and on-disk signatures. Veronig et al. (2010, ApJL 716, 57) concluded…

Solar and Stellar Astrophysics · Physics 2015-03-19 V. V. Grechnev , A. N. Afanasyev , A. M. Uralov , I. M. Chertok , M. V. Eselevich , V. G. Eselevich , G. V. Rudenko , Y. Kubo

We report on observations of a solar prominence obtained on 26 April 2007 using the Extreme Ultraviolet Imaging Spectrometer on Hinode. Several regions within the prominence are identified for further analysis. Selected profiles for lines…

Solar and Stellar Astrophysics · Physics 2015-03-13 Nicolas Labrosse , Brigitte Schmieder , Petr Heinzel , Tetsuya Watanabe

The Alfv\'en wave energy flux in the corona can be explored using the electron density and velocity amplitude of the waves. The velocity amplitude of Alfv\'en waves can be obtained from the non-thermal velocity of the spectral line…

Solar and Stellar Astrophysics · Physics 2019-07-03 Girjesh R. Gupta , G. Del Zanna , H. E. Mason

Small (400 to 4000 km) and short lived (10 to 200 km) extreme ultraviolet (EUV) brightenings, detected by the High Resolution Imager EUV (HRIEUV), have been found to be ubiquitous in the Quiet Sun (QS). Their contribution to coronal heating…

Solar and Stellar Astrophysics · Physics 2025-07-02 A. Dolliou , J. A. Klimchuk , S. Parenti , K. Bocchialini

Some of local sources of the slow solar wind can be associated with spectroscopically detected plasma outflows at edges of active regions accompanied with specific signatures in the inner corona. The EUV telescopes (e.g. SPIRIT/CORONAS-F,…

Solar and Stellar Astrophysics · Physics 2012-05-03 V. Slemzin , L. Harra , A. Urnov , S. Kuzin , F. Goryaev , D. Berghmans

We present observations of the diffraction, refraction, and reflection of a global extreme-ultraviolet (EUV) wave propagating in the solar corona. These intriguing phenomena are observed when the wave interacts with two remote active…

Solar and Stellar Astrophysics · Physics 2013-08-13 Yuandeng Shen , Yu Liu , Jiangtao Su , Hui Li , Ruijuan Zhao , Zhanjun Tian , Kiyoshi Ichimoto , Kazunari Shibata

We have measured line widths in active region coronal loops in order to determine whether the non-thermal broadening is anisotropic with respect to the magnetic field direction. These non-thermal velocities are caused by unresolved fluid…

Solar and Stellar Astrophysics · Physics 2023-08-09 Michael Hahn , Mahboubeh Asgari-Targhi , Daniel Wolf Savin

Context. The details of the spectral profiles of extreme UV emission lines from solar active regions contain key information to investigate the structure, dynamics, and energetics of the solar upper atmosphere. Aims. We characterize the…

Solar and Stellar Astrophysics · Physics 2019-06-19 Leping Li , Hardi Peter

Using detrended fluctuation analysis (DFA) and rescaled range (R/S) analysis, we investigate the scaling properties of EUV intensity fluctuations of low-latitude coronal holes (CHs) and neighboring quiet-Sun (QS) regions in signals obtained…

Solar and Stellar Astrophysics · Physics 2020-01-08 Ana Cristina Cadavid , Mari Paz Miralles , Kristine Romich

We present first observations of a dome-shaped large-scale EUV coronal wave, recorded by the EUVI instrument onboard STEREO-B on January 17, 2010. The main arguments that the observed structure is the wave dome (and not the CME) are: a) the…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. M. Veronig , N. Muhr , I. W. Kienreich , M. Temmer , B. Vrsnak

Context: A large number of the small and the short-lived EUV brightenings have been detected in the quiet Sun (QS) over the past three years, by the High Resolution Imager of the Extreme Ultraviolet Imager (HRIEUV) on board Solar Orbiter.…

Solar and Stellar Astrophysics · Physics 2024-08-09 A. Dolliou , S. Parenti , K. Bocchialini