Restricted accessMoreSectionsView PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Cite this article Harra Louise 2000Solar activity studies through coronal X–ray observationsPhil. Trans. R. Soc. A.358641–655http://doi.org/10.1098/rsta.2000.0550SectionRestricted accessSolar activity studies through coronal X–ray observations Louise Harra Louise Harra Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK Google Scholar Find this author on PubMed Search for more papers by this author Louise Harra Louise Harra Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK Google Scholar Find this author on PubMed Search for more papers by this author Published:15 February 2000https://doi.org/10.1098/rsta.2000.0550AbstractThe solar corona consists of high–temperature plasma that is contained by a wide range of magnetic field structures. The cyclic behaviour of solar activity results in continuing evolution of these structures. This evolution can be well studied by observing the X–ray and extreme ultraviolet (EUV) emission from the hot plasma which delineates the magnetic field in the corona. In this review, the X–ray images obtained from the Yohkoh mission over more than half a solar cycle and the information they provide about coronal evolution will be discussed. A variety of short–term transient brightenings observed by Yohkoh, and at EUV wavelengths by the SOHO mission, will be described and their relevance for coronal heating evaluated. Yohkoh observations have advanced our understanding of solar flares. These important results will be summarized and discussed. Finally, the current view of the nature of coronal mass ejections as deduced by Yohkoh and SOHO is presented. Previous ArticleNext Article VIEW FULL TEXT DOWNLOAD PDF FiguresRelatedReferencesDetailsCited by Ramsay G, Harra L and Kay H (2003) A search for X-ray variability in the open cluster NGC 2516, Monthly Notices of the Royal Astronomical Society, 10.1046/j.1365-8711.2003.06517.x, 341:4, (1388-1392), Online publication date: 1-Jun-2003. Thompson J and Harra L (2002) Explosive events on the Sun, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, 360:1801, (2757-2771), Online publication date: 15-Dec-2002. This Issue15 February 2000Volume 358Issue 1767Discussion Meeting Issue ‘Magnetic activity in stars, discs and quasars’ organized by D. Lynden-Bell, E. R. Priest and N. O. Weiss Article InformationDOI:https://doi.org/10.1098/rsta.2000.0550Published by:Royal SocietyPrint ISSN:1364-503XOnline ISSN:1471-2962History: Published online15/02/2000Published in print15/02/2000 License: Citations and impact KeywordsEUVSOHOYohkohX–raysolar activitysolar physics