Studies of the prominence-corona transition zone from rocket ultraviolet spectra of the March 1970 eclipse

Abstract

Slitless VUV spectra of the eclipsed Sun were obtained from a rocket experiment for the first time during the 1970 eclipse. The spatially resolved spectra of a quiescent prominence in the wavelength range 900 A.-2200 A_ consist of emission lines from ions formed in the temperature range 3.5 • 104K-3.2 • 105K. The spectral intensities have been interpreted in terms of physical parameters which indicate a transition zone of sheIMike layers, the inner the cooler and thinner, the outer the hotter and more extended. The transition zone is about 3 km thick for a model thread of 2000 km in diameter.

Extreme-ultraviolet limb spectra of a prominence observed from SKYLAB

“…Most of the radiation from the hotter regions is concentrated in the extreme ultraviolet (EUV) region of the spectrum. EUV emission-line intensities in prominences have been examined using rocket observations (Orrall and Speer 1974;Yang, Nicholls, and Morgan 1975) and using satellite observations (Withbroe 1971 ;Noyes et al 1972;Orrall and Schmahl 1976). These observations were obtained with low spectral resolution, however, and thus provided no information on line profiles.…”

EUV observations of quiescent prominences from Skylab

“…Comparison with the work of Yang et al (1975) shows systematic variations with wavelength. The ratio of the average prominence intensities reported by Yang et al to our values varies from =2.0 for wavelengths below 1240 A to 0.7 at 1394 A on the average.…”

“…The ratio of the average prominence intensities reported by Yang et al to our values varies from =2.0 for wavelengths below 1240 A to 0.7 at 1394 A on the average. As pointed out by Schmahl (1978), these systematic variations may be caused by a calibration error by Yang et al (1975).…”

“…Rocket observations of prominences were made by the consortium UV spectrograph flown during the solar eclipse of March 7, 1970(Speer et al, 1970. Orrall and Speer (1974) reported on two prominences observed by this instrument and further analysis of the material was presented by Yang et al (1975).…”