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H-alpha and Na D line profiles of the Epsilon Aur system acquired during the eclipse of 1982-84 are presented. As in previous eclipses, the H-alpha absorption core shows striking, systematic changes in width and radial velocity. H-alpha also exhibits time-varying blueshifted and redshifted emission in the line wings. It is suggested that the H-alpha emission-wing variability is due solely to ongoing processes in the extended atmosphere of the supergiant primary. As the eclipse progresses, the Na D absorption lines deepen and widen, then decrease in size as their weak emission components strengthen. The time-development of the Na D line profiles over the duration of the eclipse is consistent with the eclipsing object being a massive, cool, rotating, gaseous disk. The observed Na D line velocities combined with derived values for the mass and spatial extent of the secondary suggest that the disk is losing material.

Solid CO2films have been grown on a stainless steel substrate and processed by X-ray bombardment for up to 6 hr.. The reactions induced were monitored using X-ray photoelectron spectroscopy (XPS) and mass spectrometry. The XPS results are twofold: direct X-ray photolysis of the CO2ice produced CO and an unidentified O product, possibly atomic O; secondary effects resulting from surface reactions between CO, O, and residual H from the vacuum environment produced H2CO, CH3OH, and a water ice cap on the CO2film. The rate of production of CO from direct X-ray photolysis of CO2is measured to be 5.4 × 102molecule photon-1, corresponding to a formation cross section of 4.7 × 10-20cm2. The growth rate for the water cap is calculated to be 2.6 × 10-4monolayers s-1for a partial pressure of H equal to 2 × 10-10Torr. The appearance of gas-phase products from the film showed a time lag which indicates that the diffusion of the product species in the bulk CO2is affected by some time-dependent process, possibly the creation of defects in the film. A model for the observed time dependence of the dissociation products in the gas phase yields diffusion coefficients in the CO2of 5 × 10-12and 1 × 10-12cm2s-1, for O and CO, respectively.

A new atlas of CH_4 lines in the 1120–1800-cm^−1 region has been generated, based on laboratory spectra taken with a Nicolet interferometer at 0.06-cm^−1 resolution with 635-cm path length at pressures of 0.98 Torr, 4.86 Torr, and 19.97 Torr. A compilation of line positions and line intensities includes 1339 CH_4 lines, several hundred of which have not been previously observed.