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The Solar Maximum Year is a world-wide cooperative project to gain more insight in certain aspects of solar flares. It consists of three sub-programs: The Flare Build-up Study (FBS), the Study of Energy Release from Flares (SERF), and the Study of Travelling Interplanetary Phenomena (STIP). These programs are described. We also describe space observations to be performed during SMY, particularly the Solar Maximum Mission Satellite.Invited talk, presented at 22nd COSPAR Meeting in Bangalore on 7 June, 1979. 相似文献
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Space Science Reviews - 相似文献
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Space Science Reviews - 相似文献
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Summary Soft X-ray (0.3–3.5 keV) observations with the Imaging Proportional Counter (IPC) onboard Einstein Observatory are presented for a sample of some 20 cool stars of luminosity classes III–V. The results are compared with the Ca II H and K emission, which had served as a selection criterion.The specific X-ray flux FX is an increasing function of the specific Ca II H and K line-core flux FH+K. This correlation can be considerably improved by replacing FH+K by the excess flux (FH+K) above a certain lower limit which varies with B-V. This relation holds with little scatter over the two decades in FX in our sample. The FX-FH+K relation shows no significant dependence on spectral type or luminosity class, it suits close binaries as well as single stars. However, the coronal X-ray temperature Tc strongly depends on the luminosity class: Tc 3 106 K for dwarfs and 107 K for giants.The results are interpreted in the framework of magnetic activity. The X-ray emission and the excess Ca II H and K flux are attributed to magnetic structure in the corona and chromosphere, the magnetic features emerging from the stellar convective envelope, where they are generated by dynamo action. 相似文献
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Cornelis de Jager 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1984,4(7):303-306
A coronal explosion is a density wave observed in X-ray images of solar flares. The wave occurs at the end of the impulsive phase, which is the time at which the flare's thermal energy content has reached its maximum value. It starts in a small area from where it spreads out, mainly into one hemisphere, with velocities that tend to rapidly decrease with time, and which are between ~ 103 and a few tens of km s?1. We interpret them as magneto-hydrodynamic waves that (mainly) move downward from the low corona into denser regions. 相似文献