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Related papers: Coronal Magnetometry with EUV Permitted Lines

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The linear polarization produced by scattering processes in the hydrogen Lyman alpha line of the solar disk radiation is a key observable for probing the chromosphere-corona transition region (TR) and the underlying chromospheric plasma.…

Solar and Stellar Astrophysics · Physics 2019-08-14 Ernest Alsina Ballester , Luca Belluzzi , Javier Trujillo Bueno

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

EUV (Extreme-Ultraviolet) waves are globally propagating disturbances that have been observed since the era of the SoHO/EIT instrument. Although the kinematics of the wave front and secondary wave components have been widely studied, there…

Solar and Stellar Astrophysics · Physics 2015-10-28 K. Vanninathan , A. M. Veronig , K. Dissauer , M. S. Madjarska , I. G. Hannah , E. P. Kontar

Estimating the magnetic field strength in the solar corona is crucial for understanding different physical processes happening over diverse spatio-temporal scales. However, the high temperatures and low density of the solar corona make this…

Solar and Stellar Astrophysics · Physics 2024-03-07 Upasna Baweja , Vaibhav Pant , Iñigo Arregui

The "middle corona" is a critical transition between the highly disparate physical regimes of the lower and outer solar corona. Nonetheless, it remains poorly understood due to the difficulty of observing this faint region (1.5-3 solar…

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

We report multi-wavelength observations of four solar flares on 2014 July 07. We firstly select these flares according to the soft X-ray (SXR) and extreme ultraviolet (EUV) emissions recorded by the Extreme Ultraviolet Variability…

Solar and Stellar Astrophysics · Physics 2021-05-05 Dong Li , Alexander Warmuth , Lei Lu , Zongjun Ning

Type U radio bursts are impulsive coherent radio emissions produced by the Sun that indicate the presence of subrelativistic electron beams propagating along magnetic loops in the solar corona. In this work, we present the analysis of a…

Solar and Stellar Astrophysics · Physics 2023-01-04 S. Mancuso , D. Barghini , A. Bemporad , D. Telloni , D. Gardiol , F. Frassati , I. Bizzarri , C. Taricco

We present a detailed analysis of oxygen ion velocity distributions in the extended solar corona, based on observations made with the Ultraviolet Coronagraph Spectrometer (UVCS) on the SOHO spacecraft. Polar coronal holes at solar minimum…

Astrophysics · Physics 2009-11-13 Steven R. Cranmer , Alexander V. Panasyuk , John L. Kohl

The solar chromosphere is a transition layer between the cool, dense photosphere and the hot, rarefied corona. This boundary region plays a key role in regulating energy transport and structuring the magnetic field throughout the solar…

Solar and Stellar Astrophysics · Physics 2026-04-14 M. Kriginsky , J. Leenaarts , J. de la Cruz Rodriguez , S. Danilovic , O. Andriienko

The distribution of the coronal electron density at different distances from the Sun strongly influences the physical processes in the solar corona and is therefore a very important topic in solar physics. Most methods, including radio…

Judge et al. (2021) recently argued that a region of the solar spectrum in the near-UV between about 250 and 290 nm is optimal for studying magnetism in the solar chromosphere due to an abundance of Mg II, Fe II, and Fe I lines that sample…

Solar and Stellar Astrophysics · Physics 2023-09-12 A. G. de Wijn , P. G. Judge , R. Ezzeddine , A. Sainz Dalda

The present work illustrates the potential of a new diagnostic technique that allows the measurement of the coronal magnetic field strength in solar active regions utilizing a handful of bright \ion[Fe x] and \ion[Fe xi] lines commonly…

Solar and Stellar Astrophysics · Physics 2020-12-02 E. Landi , R. Hutton , T. Brage , W. Li

We review X-ray plasma diagnostics based on the line ratios of He-like ions. Triplet/singlet line intensities can be used to determine electronic temperature and density, and were first developed for the study of the solar corona. Since the…

High Energy Astrophysical Phenomena · Physics 2015-03-17 Delphine Porquet , Jacques Dubau , Nicolas Grosso

We investigated if signatures of coronal mass ejections (CMEs) can be retrieved in the differential emission measure (DEM) from Sun-as-a-star extreme-ultraviolet (EUV) observations. We analyzed 16 major, eruptive (i.e., associated with…

Solar and Stellar Astrophysics · Physics 2026-05-05 Angelos Michailidis , Spiros Patsourakos

Magnetic field couples the solar interior to the solar atmosphere, known as the corona. The coronal magnetic field is one of the crucial parameters which determines the coronal structures and regulates the space weather phenomena like…

Solar and Stellar Astrophysics · Physics 2022-07-26 Devojyoti Kansabanik , Divya Oberoi , Surajit Mondal

Coronal holes are the source regions of the fast solar wind, which fills most of the solar system volume near the cycle minimum. Removing stray light from extreme ultraviolet (EUV) images of the Sun's corona is of high astrophysical…

Solar and Stellar Astrophysics · Physics 2013-02-05 Paul Shearer , Richard A. Frazin , Alfred O. Hero , Anna C. Gilbert

Eclipses are very favourable for the photosphere- chromosphere and corona interface observation as the occultation takes place in space, free of parasitic light coming from the occulting disk (the Moon). Independently, EUV filtergrams of…

Solar and Stellar Astrophysics · Physics 2013-12-18 Cyrille Bazin

There is a thin transition region (TR) in the solar atmosphere where the temperature rises from 10,000 K in the chromosphere to millions of degrees in the corona. Little is known about the mechanisms that dominate this enigmatic region…