The blue Sun of 1950 September
Abstract
This paper deals with the "blue" Sun observed at Edinburgh on 1950 September 26. Spectrophotometric observations of the "blue" and normal Suns give an extinction curve of the layer causing the phenomenon. This covers the wave-length range 3800-6300 A. and shows blueing on the long wave-length side, and reddening on the short wave-length side, of a minimum situated at A 4350. This affords an experimental verification of an outstanding feature of scattering theory. It is concluded that the scattering particles producing the minimum are dielectric, and uniform in size and constitution. A relation between the size and refractive index of the dielectric partides is deduced. In addition to the selective effect, there is a heavy non-selective extinction which may arise from another system of absorbing particles in the layer. Other workers have established the source of the layer as the extensive forest fires burning in Alberta on 1950 September 23.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- 1951
- DOI:
- 10.1093/mnras/111.5.478
- Bibcode:
- 1951MNRAS.111..478W