William H. Parkinson

Measurements of coronal kinetic temperatures from 1.5 to 3 solar radii

A rocket-borne L..cap alpha.. coronagraph has been used to make the first measurements of the spectral line profile of resonantly scattered hydrogen L..cap alpha.. coronal radiation between 1.5 and 3 solar radii. These data provide, for the first time, direct measurements of coronal temperatures above 1.5 solar radii. Data were obtained in a coronal hole, quiet region, and streamer. The widths of the profiles from the quiet region decrease with height and correspond to a steady decrease in hydrogen kinetic temperature, with increasing radius, from about 2.5 x 10/sup 6/ K at rapprox. =2Rsun to about 10/sup 6/ K at rapprox. =4Rsun. In the coronal hole the measured line widths indicate a kinetic temperature of 1.8 x 10/sup 6/ K at rapprox. =2.5 Rsun.

The solar boron abundance

Positive evidence for the presence of boron in the sun is reported, and the chemical abundance of boron in the photosphere is derived from photoelectric measurements of the solar spectrum near 2500 A obtained with a rocketborne high-resolution spectrometer. Short sections of the spectrum in the vicinities of the B I lines at 2496.772 and 2497.723 A are plotted. The photospheric boron abundance is determined primarily by analyzing the solar-center spectrum near the first of the two lines in the framework of several single-component photospheric models. The logarithmic boron abundance obtained is 2.6, with an estimated uncertainty of plus or minus 0.3 dex, on the scale where that of hydrogen is 12.0. This value is shown to be in excellent agreement with that predicted for a nucleosynthesis model in which Li, Be, and B are produced by cosmic-ray spallation.

CARBON MONOXIDE IN THE ULTRAVIOLET SOLAR SPECTRUM.

Abstract : The laboratory absorption spectrum of CO at approximately 5000K has been studied in a shock tube and appears to account for some of the observed features of the solar rocket ultraviolet spectrum. (Author)

The refractive index of krypton for 168 nm ⩽ λ ⩽ 288 nm

Abstract The index of refraction of krypton has been measured at 27 points in the wavelength interval 168 nm ⩽ λ ⩽ 288 nm. The probable error of each measurement is ±0.1%. Our results are compared with other measurements. Our data are about 3.8% smaller than those of Abjean et al.