The Influence of Certain Photographic Errors on the Profiles of Absorption Lines in Stellar Spectra

Abstract

A study has been made of the Eberhard effect in its relation to the profiles of absorption lines. Measurements have been made of the depression of the background at the edge of an image, due to the inhibiting action of the products of development, for: (a) various differences between the density of the image and that of the background; (b) constant ratio of exposure of image to exposure of background, but different total densities; (c) varying time of development; (d) agitation during development; and (e) type of developer. The influence of scattered light from the back of the plate and the influence of the graininess of the emulsion have also been studied. The conclusion is reached that for Eastman 40 plates developed in D-11 at 70°F, and with a density of the continuous spectrum less than unity, the Eberhard effect and the halation from the back of the plate have a negligible influence on the profile of an absorption line. The profiles of artificial absorption lines are shown.