UK-Japan Cooperative Study of Solar Flares with the SOLAR-A Spacecraft

1991年8月30日，太阳-A（Yohkoh）使命发射成功，卫星上的科学仪器状况良好，并返回了X射线和γ射线波段的新数据。在英国和日本合作下开发和制造的布拉格晶体光谱仪揭示了日冕和耀斑诊断的新方面。在次C类活动中，色球蒸发发生了类似耀斑的现象，这可能是理解日冕加热机制的一把钥匙。首次获得了M级小耀斑中的类氢铁谱，并提高了谱的分辨率。完全蓝移的软X射线发射谱线清楚地表明色球蒸发的证据在太阳耀斑。日冕中的元素丰度有时与光球层中的元素丰度不同，并随着太阳耀斑的发展而变化。工作站上的数据分析软件相互连接，为鹿儿岛航天中心和NASA深空网络站提供了一个有效的数据分析系统。

The SOLAR-A (Yohkoh) mission was successfully launched on August 30, 1991.The onboard scientific instruments have been in good condition and returning new data of the sun in X-ray and gamma-ray wavelengths. Bragg crystal spectrometer, developed and manufactured under the UK-Japan collaboration, revealed new aspects of coronal and flare diagnostics. A flare-like chromospheric evaporation takes place in an sub C class activity, which may have a key to understand the heating mechanism of solar corona. Hydrogen like iron spectra in small M class flares were taken for the first time with an improved spectral resolution. Totally blueshifted spectra of soft X-ray emission lines clearly indicate the evidence of chromospheric evaporation in solar flares. Element abundances in the corona are sometimes different from those in the photosphere and change according to the development of solar flares. Data analysis softwares in the workstations linked together, provide an efficient analysis system of data downlinked both at Kagoshima "Space Center and at Deep Space Network Stations, NASA.