ISSN:
1573-093X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract A grazing incidence X-ray telescope on board the OSO-IV spacecraft obtained images of the Sun in the 2.5 to 12 Å waveband nearly continuously from 27 October 1967 to 12 May 1968. The instrument had sufficient spatial resolution (one and four arc minutes) and temporal resolution (5 to 20 min) to estimate the spatial characteristics of X-ray emitting regions and to monitor the temporal behavior of individual active regions. Variations in the absence of flares of as much as a factor of 10 in the X-ray output of individual regions were observed, with typical durations ranging from several hours to several days. The X-ray time variations are related to observations at optical and radio wavelengths. The results are interpreted under the assumption that the X-ray time variations are caused by temperature changes in the coronal portions of active regions. The contribution of radiative losses to the energy budget of the coronal active region is estimated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00145472
