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

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We investigate the high-speed ($v >$ 1000 km s$^{-1}$) extreme-ultraviolet (EUV) wave associated with an X1.2 flare and coronal mass ejection (CME) from NOAA active region 11283 on 2011 September 6 (SOL2011-09-06T22:12). This EUV wave…

Solar and Stellar Astrophysics · Physics 2016-10-26 Karin Dissauer , Manuela Temmer , Astrid M. Veronig , Kamalam Vanninathan , Jasmina Magdalenić

We present the first unambiguous detection of quasi-periodic wave trains within the broad pulse of a global EUV wave (so-called "EIT wave") occurring on the limb. These wave trains, running ahead of the lateral CME front of 2-4 times…

Solar and Stellar Astrophysics · Physics 2012-08-17 Wei Liu , Leon Ofman , Nariaki V. Nitta , Markus J. Aschwanden , Carolus J. Schrijver , Alan M. Title , Theodore D. Tarbell

Plumes are one of the most ubiquitous features seen at the limb in polar coronal holes and are considered to be a source of high density plasma streams to the fast solar wind. We analyze STEREO observations of plumes and aim to reinterpret…

Solar and Stellar Astrophysics · Physics 2010-08-31 Scott W. McIntosh , Davina E. Innes , Bart De Pontieu , Robert J. Leamon

Context: On 2020 May 30, small and short-lived EUV brightenings were observed in the Quiet Sun (QS) during a four minutes sequence by EUI/HRIEUV on board Solar Orbiter. Their physical origin and possible impact on coronal or Transition…

We investigate heating and evolution of flare loops in a C4.7 two-ribbon flare on 2011 February 13. From SDO/AIA imaging observations, we can identify two sets of loops. Hinode/EIS spectroscopic observations reveal blueshifts at the feet of…

Solar and Stellar Astrophysics · Physics 2015-06-18 Y. Li , J. Qiu , M. D. Ding

Images from the Solar Dynamics Observatory (SDO) at 211A are used to identify the solar source of the type III radio bursts seen in WIND/WAVES dynamic spectra. We analyse a 2.5 hour period during which six strong bursts are seen. The radio…

Solar and Stellar Astrophysics · Physics 2015-05-28 D. E. Innes , R. H. Cameron , S. K. Solanki

High-frequency wave phenomena present a great deal of interest as one of the possible candidates to contribute to the energy input required to heat the corona as a part of the AC heating theory. However, the resolution of imaging…

Solar and Stellar Astrophysics · Physics 2023-04-05 Elena Petrova , Norbert Magyar , Tom Van Doorsselaere , David Berghmans

Observations of small-scale brightenings in the low solar atmosphere can provide valuable constraints on possible heating/heat-transport mechanisms. We present a method for the detection and analysis of brightenings and demonstrate its…

Solar and Stellar Astrophysics · Physics 2021-07-30 Llŷr Dafydd Humphries , Huw Morgan , David Kuridze

The \textit{Sun Watcher using Active Pixel system detector and Image Processing}(SWAP) on board the \textit{PRoject for OnBoard Autonomy\todash 2} (PROBA\todash 2) spacecraft provides images of the solar corona in EUV channel centered at…

Solar and Stellar Astrophysics · Physics 2012-06-11 K. Chandrashekhar , S. Krishna Prasad , D. Banerjee , B. Ravindra , Daniel B. Seaton

The photometry of eclipse white-light (W-L) images showing a moving blob is interpreted for the first time together with observations from space with the PRoject for On Board Autonomy (PROBA-2) mission (ESA). An off-limb event seen with…

Solar and Stellar Astrophysics · Physics 2018-03-14 E. Tavabi , S. Koutchmy , C. Bazin

Plasma flow measurements in solar active region filaments are rare, particularly in the infrared and ultraviolet ranges that probe the chromosphere and transition region. In addition, previous studies generally focused on prominences and…

Solar and Stellar Astrophysics · Physics 2025-11-04 M. Murabito , V. Andretta , S. Parenti , C. Kuckein , S. J. Gonzàlez Manrique , S. M. Lezzi , S. L. Guglielmino

Solar flare emission at X-ray and extreme ultraviolet (EUV) energies can cause substantial enhancements in the electron density in the Earth's lower ionosphere. It is now become clear that flares exhibit quasi-periodic pulsations with…

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

Many studies of the solar corona have shown that the observed X-ray luminosity is well correlated with the total unsigned magnetic flux. In this paper we present results from the extensive numerical modeling of active regions observed with…

Astrophysics · Physics 2016-08-30 Harry P. Warren , Amy R. Winebarger

Solar activity during 2007--2009 was very low, causing anomalously low thermospheric density. A comparison of solar extreme ultraviolet (EUV) irradiance in the He II spectral band (26 to 34 nm) from the Solar Extreme ultraviolet Monitor…

Solar and Stellar Astrophysics · Physics 2015-06-15 Leonid Didkovsky , Joseph B. Gurman

Power spectra of segmentation-cell length (a dominant length scale of EUV emission in the transition region) from full-disk HeII extreme ultraviolet (EUV) images observed by the Extreme ultraviolet Imaging Telescope (EIT) onboard the Solar…

Solar and Stellar Astrophysics · Physics 2017-01-18 Leonid Didkovsky , Seth Wieman , Elena Korogodina

The extreme-ultraviolet (EUV) brightenings identified by Solar Orbiter, commonly known as campfires, are the smallest transient brightenings detected to date outside active regions in the solar corona. We investigate the spatio-temporal…

One of the most important features in the solar atmosphere is magnetic network and its rela- tionship with the transition region (TR), and coronal brightness. It is important to understand how energy is transported into the corona and how…

Solar and Stellar Astrophysics · Physics 2018-03-21 Ehsan Tavabi

We study an EUV confined ejection observed on 09 May 2012 in active region (AR) NOAA 11476. For the analysis we use observations in multiple wavelengths (EUV, X-rays, H$\alpha$, and magnetograms) from a variety of ground-based and space…

Microflares are small dynamic signatures observed in X-ray and extreme-ultraviolet channels. Because of their impulsive emission enhancements and wide distribution, they are thought to be closely related to coronal heating. By using the…

Solar and Stellar Astrophysics · Physics 2015-04-01 Fayu Jiang , Jun Zhang , Shuhong Yang