Abstract
New emission spectra of ArH and ArD between 4000 Å and 5000 Å are presented. The observed transitions are of the 2Π-2Σ+ type. All bands have the same lower 2Σ+ state as the main band at 7670 Å previously reported by Johns [1]. The new upper Π states together with the one reported by Johns form a Rydberg series tentatively assigned to have pπ symmetry. Molecular constants derived from the spectra are reported. In certain cases, hot bands were observed. The bands exhibit perturbations but the perturbing states remain unassigned.