Observations in the Southern Hemisphere of Ultra-violet Light from Celestial Objects

Abstract

THE atmosphere of the Earth is opaque to light of wave-length less than 3000 Å. It is consequently impossible to observe stellar radiation in this wave-length region from the Earth's surface. Such measurements, even if made with low spectrum resolution, would be of great importance to our understanding of the processes of energy transfer in stellar atmospheres and of their composition and could provide a critical test of theories of the interstellar medium. A significant extension of the observable wave-length range into the ultra-violet requires observations from altitudes in excess of 100 km. Such altitudes can be reached only by rockets. The first observations of this type were reported by Byram et al.¹. These, and certain later measurements, were made from vehicles launched in the northern hemisphere. This communication gives an account of the first observations to be made in this field from the southern hemisphere and in particular the first reported measurements of lunar ultra-violet irradiance to be made from rockets.