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Related papers: EUV Sunspot Plumes Observed with SOHO

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Context. The corona of the Sun is the part of the solar atmosphere with temperatures of over one million Kelvin, which needs to be heated internally in order to exist. This heating mechanism remains a mystery; we see large magnetically…

Solar and Stellar Astrophysics · Physics 2023-11-03 I. Kraus , Ph. -A. Bourdin , J. Zender , M. Bergmann , A. Hanslmeier

For the first time, we present and discuss EUV radiances of the solar transition region (TR) and corona obtained during a solar cycle. The measurements were obtained with the SOHO/coronal diagnostic spectrometer (CDS) during the period from…

Solar and Stellar Astrophysics · Physics 2017-03-30 V. Andretta , G. Del Zanna

Solar Extreme Ultraviolet (EUV) radiation creates the conducting E-layer of the ionosphere, mainly by photo ionization of molecular Oxygen. Solar heating of the ionosphere creates thermal winds which by dynamo action induce an electric…

Solar and Stellar Astrophysics · Physics 2016-09-07 Leif Svalgaard

Full-disk spectroscopic observations of the solar corona are highly desired to forecast solar eruptions and their impact on planets and to uncover the origin of solar wind. In this paper, we introduce a new multi-slit design (5 slits) to…

Solar and Stellar Astrophysics · Physics 2024-06-12 Lami Chan , Hui Tian , Xianyu Liu , Tibor Török , Xianyong Bai , Yufei Feng , Dipankar Banerjee

Observations of cool stars reveal dark spot-like features on their surfaces. Compared to sunspots, starspots can be bigger or cover a larger fraction of the stellar surface. While sunspots appear only at low latitudes, starspots are also…

Solar and Stellar Astrophysics · Physics 2014-12-24 Rakesh K. Yadav , Thomas Gastine , Ulrich R. Christensen , Ansgar Reiners

The availability of high quality synoptic observations of the EUV and visible corona during the SOHO mission has advanced our understanding of the low corona manifestations of CMEs. The EUV imager/white light coronagraph connection has been…

Solar and Stellar Astrophysics · Physics 2009-08-11 Eva Robbrecht , Spiros Patsourakos , Angelos Vourlidas

Sunspots, which harbor both magnetic polarities within one penumbra, are called delta-spots. They are often associated with flares. Nevertheless, there are only very few detailed observations of the spatially resolved magnetic field…

Solar and Stellar Astrophysics · Physics 2013-12-19 Horst Balthasar , Christian Beck , Rohan E. Louis , Meetu Verma , Carsten Denker

Spatially averaged (> 50'') EUV spectral lines in the transition region of solar quiet regions are known to be redshifted. Because the mechanism underlying this phenomenon is unclear, we require additional physical information on the lower…

Solar and Stellar Astrophysics · Physics 2016-01-13 N. Kitagawa , H. Hara , T. Yokoyama

Transition region lines in active regions can become strongly enhanced in coronal footpoints and active region blinkers. The weak transition region lines found in the Solar-B/EIS wavebands will thus become useful for diagnostic studies of…

Astrophysics · Physics 2007-08-14 P. R. Young

Strong EUV lineshifts in solar spectra are generally indicative of highly dynamic and explosive events that are easily detected in comparable-wavelength EUV images, with the strongest such line shifts (several 100 km/s) occurring in solar…

Solar and Stellar Astrophysics · Physics 2025-12-04 Alphonse C. Sterling , Louise K. Harra , Navdeep K. Panesar , Ronald L. Moore

Bright points (BPs) in the solar photosphere are radiative signatures of magnetic elements described by slender flux tubes located in the darker intergranular lanes. They contribute to the ultraviolet (UV) flux variations over the solar…

Solar and Stellar Astrophysics · Physics 2016-08-11 T. L. Riethmüller , S. K. Solanki , S. V. Berdyugina , M. Schüssler , V. Martínez Pillet , A. Feller , A. Gandorfer , J. Hirzberger

It is generally believed that sunspots are the emergent part of magnetic flux tubes in the solar interior. These tubes are created at the base of the convection zone and rise to the surface due to their magnetic buoyancy. The motion of…

Solar and Stellar Astrophysics · Physics 2015-05-14 Franck Plunian , Graeme Sarson , Rodion Stepanov

High resolution spectropolarimetric observations by Hinode reveal the existence of supersonic downflows at the umbra-penumbra boundary of 3 sunspots that was recently reported by Louis et al. (2010). These downflows are observed to be…

Solar and Stellar Astrophysics · Physics 2015-03-17 Rohan E. Louis , Luis R. Bellot Rubio , Shibu K. Mathew , P. Venkatakrishnan

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

Coronal holes are regions on the Sun's surface that map the foot-prints of open magnetic field lines. We have developed an automated routine to detect and track boundaries of long-lived coronal holes using full-disk EUV images obtained by…

Solar and Stellar Astrophysics · Physics 2015-02-24 Chris Lowder , Jiong Qiu , Robert Leamon , Yang Liu

For the past six years, the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory has been monitoring changes in the Sun's extreme ultraviolet output over a range of timescales. Its primary function is to provide…

Solar and Stellar Astrophysics · Physics 2017-01-11 Ryan O. Milligan

Coronal Bright Points (CBPs) are ubiquitous structures in the solar atmosphere composed of hot small-scale loops observed in EUV or X-Rays in the quiet Sun and coronal holes. They are key elements to understand the heating of the corona;…

Solar and Stellar Astrophysics · Physics 2022-08-24 D. Nóbrega-Siverio , F. Moreno-Insertis

Several coronal bright points identified in a quiet region of the Sun from SOHO/EIT Fe XII images are found to have a time evolution from birth to decay which is extremely well correlated with the rise and fall of magnetic flux as…

Astrophysics · Physics 2009-10-31 Paweł Preś , Kenneth J. H. Phillips

Various small-scale structures abound in the solar atmosphere above active regions, playing an important role in the dynamics and evolution therein. We report on a new class of small-scale transition region structures in active regions,…

Solar and Stellar Astrophysics · Physics 2016-10-05 Zhenyong Hou , Zhenghua Huang , Lidong Xia , Bo Li , Maria S. Madjarska , Hui Fu , Chaozhou Mou , Haixia Xie

The generation of magnetic flux in the solar interior and its transport from the convection zone into the photosphere, the chromosphere, and the corona will be in the focus of solar physics research for the next decades. With 4m class…

Solar and Stellar Astrophysics · Physics 2015-05-18 R. Schlichenmaier , N. Bello Gonzalez , R. Rezaei , T. A. Waldmann