Abstract
The Naval Research Laboratory's most recent Earth-orbiting coronagraph, called Solwind, has been observing the Sun's outer corona (2.6–10.0 R ⊙) at 10-min intervals since March 28, 1979. These observations provide the first comprehensive view of coronal transients near the peak of a sunspot cycle. Six, well-defined transients in our quick-look data have masses ranging from 7 × 1014 g to 2 × 1016 g and outward speeds ranging from 150 km s−1 to 900 km s−1. These values are comparable to the ones that were obtained with the OSO-7 and Skylab observations during the declining phase of the last sunspot cycle. Although the amount of quick-look data is not sufficient to provide meaningful statistics, the coronal transients near sunspot maximum seem to occur with a greater frequency and a wider latitude range than the transients during the declining phase of the cycle. In both eras, there is a good, but imperfect, association between the occurrence of coronal transients and surface phenomena such as eruptive prominences and flares.
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On leave from the High Altitude Observatory, National Center for Atmospheric Research, Boulder, Colo. 80307, U.S.A. Now at Goddard Space Flight Center; Greenbelt, Md. 20771, U.S.A.
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Poland, A.I., Howard, R.A., Koomen, M.J. et al. Coronal transients near sunspot maximum. Sol Phys 69, 169–175 (1981). https://doi.org/10.1007/BF00151264
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DOI: https://doi.org/10.1007/BF00151264