English
Related papers

Related papers: Small-scale impulsive EUV emission enhancements al…

200 papers

Evidence for small amounts of very hot plasma has been found in active regions and might be the indication of an impulsive heating, released at spatial scales smaller than the cross section of a single loop. We investigate the heating and…

Solar and Stellar Astrophysics · Physics 2016-01-13 E. Tajfirouze , F. Reale , A. Petralia , P. Testa

We analyze and model an M1.0 flare observed by SDO/AIA and Hinode/EIS to investigate how flare loops are heated and evolve subsequently. The flare is composed of two distinctive loop systems observed in EUV images. The UV 1600 \AA emission…

Solar and Stellar Astrophysics · Physics 2015-06-11 Y. Li , J. Qiu , M. D. Ding

We analyzed spectral and imaging data from the Interface Region Imaging Spectrograph (IRIS), images from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO), and magnetograms from the Helioseismic and Magnetic…

Solar and Stellar Astrophysics · Physics 2017-07-12 C. E. Alissandrakis , A. Koukras , S. Patsourakos , A. Nindos

We observe plasma flows in cool loops using the Slit-Jaw Imager (SJI) onboard the Interface Region Imaging Spectrometer (IRIS). Huang et al. (2015) observed unusually broadened Si IV 1403 angstrom line profiles at the footpoints of such…

Solar and Stellar Astrophysics · Physics 2020-05-27 A. K. Srivastava , Yamini K. Rao , P. Konkol , K. Murawski , M. Mathioudakis , Sanjiv K. Tiwari , E. Scullion , J. G. Doyle , B. N. Dwivedi

One of the most interesting discoveries of the X-ray Telescope and EUV Imaging Spectrometer (EIS) on board the Hinode solar observatory is the presence of persistent high temperature high speed outflows from the edges of active regions.…

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

Transition-region explosive events (EEs) are characterized by non-Gaussian line profiles with enhanced wings at Doppler velocities of 50-150 km/s. They are believed to be the signature of solar phenomena that are one of the main…

Solar and Stellar Astrophysics · Physics 2016-11-15 Z. Huang , M. S. Madjarska , E. M. Scullion , L. -D. Xia , J. G. Doyle , T. Ray

Solar flares typically have an impulsive phase that followed by a gradual phase as best seen in soft X-ray emissions. A recent discovery based on the EUV Variability Experiment (EVE) observations onboard the Solar Dynamics Observatory (SDO)…

Solar and Stellar Astrophysics · Physics 2015-04-22 Kai Liu , Jie Zhang , Yuming Wang , Xin Cheng

The High Resolution Imager (HRI_EUV) telescope of the Extreme Ultraviolet Imager (EUI) instrument onboard Solar Orbiter has observed EUV brightenings, so-called campfires, as fine-scale structures at coronal temperatures. The goal of this…

Solar and Stellar Astrophysics · Physics 2022-10-18 Krzysztof Barczynski , Karen A. Meyer , Louise K. Harra , Duncan H. Mackay , Frederic Auchere , David Berghmans

Here we present the study of a compact emission source during an X1.3 flare on 2022-March-30. Within a $\sim41$~s period (17:34:48 UT to 17:35:29 UT), IRIS observations show spectral lines of Mg II, C II and Si IV with extremely broadened,…

Solar and Stellar Astrophysics · Physics 2023-09-13 Yan Xu , Graham S. Kerr , Vanessa Polito , Nengyi Huang , Ju Jing , Haimin Wang

Since its launch in 2010, the Solar Dynamics Observatory (SDO) has provided continuous, high-cadence, multi-wavelength observations of the Sun, capturing thousands of solar flares and offering new insights into coronal dynamics. Among the…

Solar and Stellar Astrophysics · Physics 2026-05-18 Harry J. Greatorex , Aisling N. O'Hare , Susanna Bekker , Ryan J. Campbell , Daniel C. Keane , Ryan O. Milligan

Multi-wavelength ultraviolet (UV) observations by the IRIS satellite in active region NOAA 12529 have recently pointed out the presence of long-lasting brightenings, akin to UV bursts, and simultaneous plasma ejections occurring in the…

Solar and Stellar Astrophysics · Physics 2018-12-19 Salvo L. Guglielmino , Peter R. Young , Francesca Zuccarello

We perform multiwavelength time-distance analysis of a fan loop system anchored in an isolated sunspot region AR 12553. The active region was observed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. We measure…

Solar and Stellar Astrophysics · Physics 2020-07-01 Aishawnnya Sharma , Durgesh Tripathi , Robertus Erdelyi , G. R. Gupta , G. A. Ahmed

The Soft X-ray intensity of loops in active region cores and corresponding footpoint, or moss, intensity observed in the EUV remain steady for several hours of observation. The steadiness of the emission has prompted many to suggest that…

Astrophysics · Physics 2009-11-13 A. R Winebarger , H. P. Warren , D. A. Falconer

Extreme-ultraviolet (EUV) waves are one of the large-scale phenomena on the Sun. They are defined as large propagating fronts in the low corona with speeds ranging from a few tens km/s to a multiple of 1000 km/s. They are often associated…

Solar and Stellar Astrophysics · Physics 2023-10-20 Ramesh Chandra , Pooja Devi , P. F. Chen , Brigitte Schmieder , Reetika Joshi , Bhuwan Joshi , Arun Kumar Awasthi

Type-I bursts (i.e. noise storms) are the earliest-known type of solar radio emission at the metre wavelength. They are believed to be excited by non-thermal energetic electrons accelerated in the corona. The underlying dynamic process and…

Solar and Stellar Astrophysics · Physics 2017-06-28 Chuanyang Li , Yao Chen , Bing Wang , Guiping Ruan , Shiwei Feng , Guohui Du , Xiangliang Kong

In this research, we investigate Explosive Events (EEs) in the off-limb solar atmosphere, with simultaneous observations from the Si IV, Mg II k, and slit-jaw images (SJI) of the Interface Region Imaging Spectrograph (IRIS), on 17 August…

Solar and Stellar Astrophysics · Physics 2022-07-06 E. Tavabi , S. Zeighami , M. Heydari

Loops are one of the fundamental structures that trace the geometry of the magnetic field in the solar atmosphere. Their evolution and dynamics provide a crucial proxy for studying how the magnetized structures are formed and heated in the…

Solar and Stellar Astrophysics · Physics 2020-01-08 Zhenghua Huang , Bo Li , Lidong Xia , Mijie Shi , Hui Fu , Zhenyong Hou

Advancements in instrumentation have revealed a multitude of small-scale EUV events in the solar atmosphere. Our aim is to employ high-resolution magnetograms to gain a detailed understanding of the magnetic origin of such phenomena. We…

Solar and Stellar Astrophysics · Physics 2024-06-19 D. Nóbrega-Siverio , I. Cabello , S. Bose , L. H. M. Rouppe van der Voort , R. Joshi , C. Froment , V. M. J. Henriques

Recurrent and propagating intensity perturbations are frequently observed in extreme ultraviolet (EUV) channels along coronal fan loops above sunspots, and these perturbations are suggested to be slow magnetoacoustic waves. Numerous studies…

Solar and Stellar Astrophysics · Physics 2025-02-26 Junwei Zhao , Tongjiang Wang , Ruizhu Chen

We have studied the relationship between the velocity and temperature of a solar EUV jet. The highly accelerated jet occurred in the active region NOAA 10960 on 2007 June 5. Multi-wavelength spectral observations with EIS/Hinode allow us to…

Solar and Stellar Astrophysics · Physics 2015-06-11 Y. Matsui , T. Yokoyama , N. Kitagawa , S. Imada