Simultaneous visible and near-infrared spectrophotometry of Comet Austin 1989c

Abstract

Simultaneous visible and near-infrared spectra of Comet Austin were obtained wit the 1.5 m and 2.3 m telescopes of the University of Arizona Observatories on 1990 May 16. The visible spectrum obtained with the IHW spectrograph covers the 3126-9490 A wavelength interval, while the near-infrared spectrum obtained with the germanium spectrometer covers the 9036-12794 A wavelength interval. Simultaneous measurements of integrated band fluxes are presented for the CN B 2Sigma(+) - X 2Sigma(+) (violet) and A 2Pi - X 2Sigma(+) (red) systems. A CN spectrum and CN band flux ratios calculated from a fluoresence equilibrium model are also presented. From a comparison between the observed and calculated CN spectra and band flux ratios, it is found that red system oscillator strengths determined from recent ab initio calculations appropriately describe the radiative properties of CN molecules.