Initial results from the S-056 X-ray telescope on Skylab
The S-056 instrument on Skylab-ATM consists of a glancing incidence X-ray telescope with a camera, five X-ray filters, and two small proportional counters to monitor X-rays from the whole sun in the wavelength range from 2 to 18 A. The telescope reflectivity and filter transmissions limit the photographs to the wavelength ranges from 6 to 18 A and from 27 to 37 A. Hence, the instrument is most useful for the study of active regions and solar activity. Active regions usually have bright cores which often appear as linear features straddling the magnetic field neutral line. A large loop appearing on the west limb in connection with prominence activity on Aug. 13, 1973, was analyzed using proportional counter data and photographs. Crude spectral analysis indicates the loop temperature reached 6 million K and the density was enhanced to a few times that obtained from quiet coronal models. Over a hundred solar flares were photographed during the three Skylab missions. Illustrative examples are discussed for solar flares and other transient coronal phenomena.