ABSTRACT Variations in chemical composition during solar flares have been inferred from elemental abundance changes in cosmic ray fluxes, but have so far not been detected spectroscopically.

We present here the first spectroscopic evidence for the variation of the coronal calcium abundance in high-temperature solar flare plasmas. The analysed data consist of the high-resolution

X-ray flare spectra (λ /Δλ ≈ 4,000) observed with the Bent Crystal Spectrometer (BCS) on board the Solar Maximum Mission (SMM) satellite and described in detail by Acton _et al._1. The

observed abundance variation has important consequences for the analysis and interpretation of XUV and X-ray spectra. Access through your institution Buy or subscribe This is a preview of

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ASTROSPHERES AROUND THREE MAIN-SEQUENCE STARS AND THEIR MASS-LOSS RATES Article 12 April 2024 SOLAR FLARE ACCELERATES NEARLY ALL ELECTRONS IN A LARGE CORONAL VOLUME Article Open access 08

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Book  Google Scholar  Download references AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Space Research Centre, Polish Academy of Sciences, Kopernika 11, Wroclaw, Poland J. Sylwester *

Mullard Space Science Laboratory, Holmbury St Mary, Dorking, Surrey, RH5 6NT, UK J. R. Lemen * Laboratory for Space Research, Beneluxlaan 21, Utrecht, The Netherlands R. Mewe Authors * J.

Sylwester View author publications You can also search for this author inPubMed Google Scholar * J. R. Lemen View author publications You can also search for this author inPubMed Google

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Sylwester, J., Lemen, J. & Mewe, R. Variation in observed coronal calcium abundance of X-ray flare plasmas. _Nature_ 310, 665–666 (1984). https://doi.org/10.1038/310665a0 Download

citation * Received: 19 March 1984 * Accepted: 20 June 1984 * Issue Date: 23 August 1984 * DOI: https://doi.org/10.1038/310665a0 SHARE THIS ARTICLE Anyone you share the following link with

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